For athletes across all sports, few experiences are as agonizing as being forced to leave competition with a sudden muscle cramp. These painful, uncontrolled spasms — formally known as exercise-associated muscle cramps — have frustrated athletes, coaches and researchers for decades.

Scientists have traditionally attributed exercise-induced cramps to dehydration or electrolyte imbalances. However, this theory left unanswered questions. For example, many well-hydrated athletes experience cramps, while others competing in hot, humid conditions remain unaffected.

A growing body of research is challenging this explanation, pointing instead to the playing surface as a critical factor.

In my work as a sports scientist, I study how different variables affect athletic performance. Work from my team has found that specific qualities of playing surfaces can lead to early neuromuscular fatigue and unexpected muscle cramps.

Muscle cramps and playing surfaces

As muscles fatigue, the normal balance between signals in the nervous system that direct muscles to contract and relax become disrupted. Muscle spindles, which sense stretch, increase their firing rate. Meanwhile, inhibitory feedback from Golgi tendon organs — a part of the nervous system at the intersection of muscle fibers and tendons — declines.

In other words, muscles are getting mixed signals about whether to contract or relax. The result is excessive activation of motor neurons that stimulate muscle fibers into a sustained, involuntary contraction — a cramp.

Recent studies suggest that competing on surfaces with unfamiliar mechanical properties — such as stiffness and elasticity — can accelerate neuromuscular fatigue. Surfaces alter the mechanics of your muscles and joints. If your neuromuscular system is not accustomed to these demands, fatigue can prematurely set in and create the conditions for cramping.

In one study, my team and I found a 13% difference in muscle activity among runners performing on fields of varying stiffness and elasticity. Another study from my team found a 50% difference in hamstring activity among athletes performing identical drills on different types of turf.

Beyond sports-specific performance metrics, biomechanics research has long shown that altering the properties of playing surfaces changes muscle stiffness, joint loading and range of motion. These variables directly affect fatigue. Muscles crossing multiple joints such as the hamstrings appear especially vulnerable to

Preventing cramps during exercise

If playing surfaces influence fatigue, then managing how they interact with players could help prevent cramps.

Researchers have proposed developing regional databases cataloging the mechanical characteristics of competition surfaces for sports such as tennis. With this data, coaches and sports organizations could tailor training environments to mimic competitive conditions, reducing the shock of unfamiliar surfaces. It's not necessarily the inherent properties of the surface that causes cramping, but rather how similar or different they are from what an athlete is used to.

Consider a soccer team that practices on a soft surface but competes on a more stiff surface. Without preparation, the shift in how their muscles will be used may lead to premature fatigue and cramps during competition. By incorporating drills that replicate how athletes' muscles will be activated on competition turf could help the team better prepare for game conditions.

Similarly, a basketball team accustomed to new hardwood may benefit from training sessions on worn or cushioned courts that simulate upcoming away venues.

The key is systematic exposure. Conditioning on surfaces that replicate competitive demands acclimatizes the neuromuscular system, lowering fatigue risk and potentially reducing the risk of cramps.

Toward a holistic approach to cramps

Hydration and nutrition remain essential for performance. But accounting for conditioning, footwear traction and adaptation to different playing surfaces could help sports medicine move toward a more complete solution to exercise-associated muscle cramps.

With continued research and technology development, cramps may no longer need to be a frustrating inevitability. Instead, athletes and coaches could anticipate them, adjust training to match surface demands, and take steps to prevent them before they derail performance.

The future of cramp prevention may lie in real-time monitoring. Advances in a combination of wearable biosensors to detect neuromuscular fatigue, surface testing equipment and machine learning could help predict individualized cramp risk. Coaches might then adjust practice plans, make in-game substitutions or even adapt surface conditions when possible.

By better preparing athletes for the mechanical demands of competition surfaces, teams may protect their athletes' health and ensure top performers are available when the game is on the line.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

An estimated 90 million to 100 million Americans will tune in to watch the Super Bowl this Sunday. Unlikely to be mentioned during the festivities is this sobering but significant side note: Athletes participating in collision sports are among those at highest risk for concussion.

That risk is not limited to professional football. Researchers estimate that 4 million sports and recreation-related concussions occur in the U.S. every year, across all sports and all levels of play and in both games and practices. They happen to athletes and kids playing basketball and soccer and weekend warriors who bicycle and ski. But thousands of concussions also result from car accidents, slips and trips or other blows to the head.

I’m the director of the University of Michigan Concussion Center, and I have been researching brain injuries for nearly a quarter-century. Across the globe, hundreds more researchers like me have dedicated their careers to understanding concussions and traumatic brain injuries – and, most critically, how to prevent and treat them. While tremendous progress has been made, much more remains to be done.

The backstory

When I began my career, concussions were broadly viewed as “getting your bell rung.” It was not uncommon for an athlete who had been knocked out to be sent back into a game within 20 minutes of injury.

The devastating results of repeat concussions without appropriate treatment led to the adoption of sweeping legislation that specifically addressed youth sports concussions.

That legislation, enacted between 2009 and 2014, is law in all 50 states. Although it varies from state to state, youth athletes now receive annual education on concussions. Those suspected of having a concussion must be removed from play, and concussed athletes can’t play their sport until cleared by a medical professional.

In 2005, researchers discovered the first case of chronic traumatic encephalopathy in a former professional football athlete. The degenerative brain disease is characterized by protein deposits that have been linked to concussions and repeated head impacts.

This monumental finding occurred concurrently with U.S. military involvement in Iraq and Afghanistan. For both conflicts, traumatic brain injury became the signature injury of returning veterans, and the U.S. government increased funding to study short- and long-term effects of concussion.

In addition, sports organizations reversed their prior stance and acknowledged the link between concussions and long-term injury. They began supporting policies that embraced evidence-based rule changes to reduce concussion risk.

The golden age of concussion research

Those events laid the foundation for a new generation of scientists to explore precise ways to diagnose concussions, develop novel treatment options and understand who’s most at risk for negative long-term outcomes.

That includes three transformative studies that are currently underway in the U.S.: TRACK-TBI, which is evaluating 3,000 patients across traumatic brain injury spectrum; NFL-LONG, which tracks former NFL players; and the CARE Consortium, which has enrolled more than 55,000 military service academy members and collegiate athletes to better understand the short- and long-term effects of concussion.

The CARE Consortium, which I co-lead, has produced more than 100 peer-reviewed papers that have contributed to overall improvements in concussion diagnosis and management. Notably, we reported that recovery from a concussion may take up to one month. We also discovered that male and female athletes return to post-concussion play at the same rate and identified blood-based markers that may eventually serve as the gold standard for concussion diagnosis.

My colleagues and I are now starting follow-up evaluations of the CARE Consortium participants to better understand the long-term effects of injury. Those findings, along with work from other studies, will inform researchers on the risk of long-term neurodegeneration and shine a light on ways to intervene with medications and therapies.

The future of concussion science

Concussion research is flourishing. Since the first modern case of chronic traumatic encephalopathy was identified 17 years ago, more than 13,000 papers have been published in the medical literature. Although researchers have much more to learn, the advances in concussion care over the past 20 years are clearly significant. Concussed athletes are now kept off the playing field substantially longer, standardized assessment protocols are widespread and rules are in place to reduce concussion risk.

Findings from these studies will never grab headlines as the Super Bowl does, and some may say that policy changes should happen faster. Admittedly, the scientific process is slow, but decisions based on limited research are rarely, if ever, the right decision. But one day, this largely unheralded work will keep sports safe and its participants whole in body and mind.

This article is republished from The Conversation under a Creative Commons license. Read the original article. The views expressed are those of the author and do not necessarily reflect the views of the publisher. 

A man in North Carolina died from a rare "brain-eating" amoeba infection after swimming in a lake at a local water park, according to news reports.

The 59-year-old man became ill after visiting Fantasy Lake Water Park, a man-made lake in Cumberland County, on July 12, according to The New York Times.

The man tested positive for Naegleria fowleri, a single-celled organism that's naturally found in warm freshwater, such as lakes and rivers, the North Carolina Department of Health and Human Services (NCDHH) said in a statement. In the U.S., most infections occur in southern states, particularly during the summer months after it has been hot for prolonged periods, which raises the water temperature, NCDHH said. [5 Key Facts About Brain-Eating Amoeba]

Swallowing Naegleria fowleri in water will not cause an infection. But if water containing this amoeba goes up the nose, the organism can enter the brain and be fatal — the amoeba destroys brain tissue, which results in brain swelling and usually death, according to the Centers for Disease Control and Prevention (CDC).

Still, infections are extremely rare. From 1962 to 2018, there were just 145 cases of Naegleria fowleri reported in the U.S., according to NCDHH. But the illness has a high fatality rate — of the 145 cases, just 4 people survived.

"Our sympathies are with the family and loved ones," epidemiologist Dr. Zack Moore said in the statement. "People should be aware that this organism is present in warm freshwater lakes, rivers and hot springs across North Carolina, so be mindful as you swim or enjoy water sports."

There is no rapid test for Naegleria fowleri in water — identifying the organism can take weeks, according to the CDC. This means that people who go swimming in warm freshwater should assume that there is a low risk of infection, the CDC says.

If you choose to go swimming in warm freshwater, you can try to avoid having water go up your nose by holding your nose closed, using nose clips or keeping your head above water, the CDC says. People can also lower their risk by avoiding swimming in warm freshwater during periods of particularly high water temperature and low water levels, the NCDHH said.

In 2016, an 18-year-old woman from Ohio died from Naegleria fowleri after going white-water rafting at an outdoor recreation center in North Carolina.

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Originally published on Live Science.

It's a common piece of surfing wisdom that where dolphins swim, there are never sharks. But for ocean-goers who take comfort in a pod of dolphins swimming by, shark experts have bad news.

"This is a myth," Andrew Nosal, a shark expert at the University of San Diego, told Live Science in an email.

And this myth couldn't be farther from the truth, Stephen Kajiura, a shark expert at Florida Atlantic University, said. "If anything, it's the opposite," he told Live Science, "If you see dolphins, more often than not, there might be sharks in that same area." [Why Do Sharks and Whales Swim So Differently?] 

That's because sharks and dolphins — both of whom are carnivores — go to the same spots to hunt.

The myth stems from the false notion that dolphins are the natural enemies of sharks, and that sharks will do anything to avoid them. There's a kernel of truth in there. While dolphins and sharks generally swim side by side "minding their own business," dolphins occasionally antagonize sharks when they feel threatened, Kajiura said. These more aggressive dolphins will ram sharks with their noses, or slam into them with the whole force of their bodies. Sharks sometimes even swim away from encounters bruised and battered. (Orca whales, the largest member of the dolphin family, are also known to hunt sharks.)

Dolphin-shark face-offs are "more the exception than the norm," Kajiura said. Still, pop-culture grabbed onto the image of the shark-fighting dolphin. The popular television series "Flipper," about two boys and their pet dolphin, was especially guilty of perpetuating the myth that dolphins scare off sharks, Nosal said. The show depicted Flipper fiercely chasing sharks away from his beloved owners.

Unfortunately for surfers and swimmers, Flipper isn't an accurate depiction of typical dolphin behavior. But if you're concerned about sharks, there are rules you can follow to minimize your risk of encountering one of these creatures.

First, avoid swimming at sunrise and sunset, when visibility is lower. At these times, it's much more difficult for sharks to distinguish a swimmer from a tasty fish, Kajiura said. Avoid swimming where sharks like to hang out — around drop-offs (an underwater slope or cliff) and kelp beds, large schools of fish or fishing boats, he added. Finally, always swim with others and try to frequent beaches with a lifeguard on duty, Nosal said.

Most importantly, swimmers should remember that although the odds of getting attacked by a shark are "vanishingly small" (sharks cause just one death a year in the United States, on average), the ocean is still shark territory.

"Swimmers need to have the right attitude about swimming in the ocean," Nosal said, "There's no such thing as 'shark infested waters.' The sharks live in the ocean. That is their home."

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Originally published on Live Science.

Not to spoil your summer pool fun, but outbreaks of "crypto," a swimming-related diarrheal illness, are on the rise, according to a new report.

From 2009 to 2017, there were nearly 450 outbreaks of crypto (short for cryptosporidiosis) reported in the U.S., which resulted in more than 7,400 illnesses, according to the report from the Centers for Disease Control and Prevention (CDC). What's more, outbreaks of the illness — which is caused by a hardy parasite called Cryptosporidium — increased 13% per year over the eight-year study period, the authors said.

Cryptosporidium causes profuse, watery diarrhea that can last up to three weeks, according to the CDC. The parasite is the leading cause of outbreaks tied to recreational water use, such as swimming in pools and lakes. The organism is protected by an outer shell that allows it to survive even in chlorinated water for up to 10 days or more. [7 Common Summer Health Concerns]

People can become infected with the parasite after swallowing contaminated water from swimming pools, lakes or rivers, the CDC said.

Among the 444 crypto outbreaks reported from 2009 to 2017, 35% were tied to exposure to treated swimming pools, the report found. These outbreaks tended to peak in the months of June through August.

Although swimming pools are a common source of crypto outbreaks, they aren't the only source. Other major sources of crypto outbreaks included exposure to cattle, which was tied to about 15% of outbreaks; exposure to infected people — particularly children — at day care centers, which was tied to about 13% of outbreaks; and exposure to contaminated food, particularly raw milk or raw apple cider, which was tied to about 5% of outbreaks. (Cryptosporidium can spread from person-to-person via the "fecal-oral route," for example, when people touch surfaces that are contaminated by poop of an infected person. Given that young children may not have the best toileting and hand-washing skills, they can contaminate surfaces and spread the parasite, making daycare centers hot spots for outbreaks.)

The authors note that the development of improved testing methods for the Cryptosporidium parasite may have contributed to the increase in reported outbreaks seen in the study.

"We know more laboratories are using a test that can all at once test for bacteria, viruses and parasites that cause diarrhea," including Cryptosporidium, said study lead author Dr. Radhika Gharpure, of the CDC's Waterborne Disease and Prevention Branch. But the yearly number of crypto cases was increasing even before the widespread use of these tests, so a combination of factors may be contributing to the rise, Gharpure told Live Science.

The CDC is developing a DNA-based tracking system called CryptoNet, which will help researchers better track how Cryptosporidium spreads and help detect outbreaks, Gharpure said.

To prevent crypto outbreaks, the CDC recommends that people not swim or attend day care if they are ill with diarrhea. Those with diarrhea should continue to avoid swimming and day-care settings for at least two weeks after their symptoms resolve, the CDC said. People should also avoid swallowing water while swimming and wash their hands frequently, including after using the toilet, changing diapers, caring for someone with diarrhea or handling animals.

• 8 Awful Parasite Infections That Will Make Your Skin Crawl
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• 5 Deadly Diseases Emerging from Global Warming

Originally published on Live Science.

Elite athletes not only have stronger hearts and fitter muscles than the average Joe, but they also sport special gut bacteria that may actually boost their performance, a new study suggests.

The study, published today (June 24) in the journal Nature Medicine, shows that marathon runners and endurance athletes have higher levels of a bacteria called Veillonella in their guts, particularly after finishing a race, compared with sedentary people.

What's more, when the researchers isolated a strain of Veillonella from a marathon runner and administred this bacteria to mice, they found that the mice ran for 13% longer on a treadmill test, compared with mice not given Veillonella.

It appears that Veillonella feeds on lactic acid, a compound produced in the muscles during exercise; in turn, the bacteria produce a compound called propionate, which may aid athletic performance, the researchers said. [5 Most Amazing Marathon Feats]

According to the authors, it might one day be possible to give non-athletes a probiotic with Veillonella to increase their capacity for exercise. However, much more research would be needed to prove this out.

"What we envision is a probiotic supplement that people can take that will increase their ability to do meaningful exercise and therefore protect them against chronic diseases including diabetes," study co-author Aleksandar Kostic, an assistant professor of microbiology at the Joslin Diabetes Center in Boston, said in a statement.

Several of the study authors are founders of a company called FitBiomics, which aims to identify new probiotic bacteria for use in exercise performance and recovery.

Endurance and the gut

The study researchers analyzed stool samples from 15 people who ran the Boston Marathon in 2015 and compared them with samples from 10 sedentary people.

They found that, while levels of Veillonella were virtually non-existent in samples from sedentary people, they spiked in marathon runners shortly after the race.

A second analysis of 87 ultra-marathoners — those who run races longer than a marathon's 26.2 miles (42.2 kilometers) and Olympic-trial rowers — showed a similar result: Levels of Veillonella significantly increased after endurance exercise.

Veillonella appears to be relatively unique among gut bacteria in that it uses lactate or lactic acid as its sole carbon fuel source, Kostic said.

Studies in mice showed that, indeed, lactic acid from the blood can cross over into the intestines, where Veillonella uses it as a food source and subsequently generates propionate.

The researchers hypothesize that athletes and Veillonella have a "symbiotic" relationship: The higher levels of lactic acid in athletes' guts favor the growth of Veillonella, and these bacteria in turn produce a compound that aids in performance.

"It creates this positive feedback loop. The host is producing something that this particular microbe favors. Then in return, the microbe is creating something that benefits the host," Kostic said.

An exercise probiotic?

"The results are fascinating," said Dr. Emeran Mayer, a gastroenterologist at the David Geffen School of Medicine at UCLA and author of "The Mind-Gut Connection" (Harper Wave, 2016), who wasn't involved in the study. [Don't Be Fooled: 5 Probiotics Myths]

If the findings are reproduced with additional human studies, they could have implications for treating people involved with high-intensity physical activity, such as athletes or people in the military, Mayer said.

Still, Mayer said it's hard to predict whether a Veillonella probiotic could increase a person's capacity for exercise. It may be that some people develop higher levels of Veillonella in their guts early in life, and that these people are more likely to become athletes, he said.

In addition, it's unclear if a probiotic could increase levels of Veillonella in the gut of non-athletes; and even if possible, it could have unwanted side effects, he added. Still, "It is certainly an exciting possibility," Mayer said.

• 5 Ways Gut Bacteria Affect Your Health
• How to Build the World's Fastest Marathoner
• 8 Tips to Be a Probiotic Pro

Originally published on Live Science.

March Madness is in full swing, but along with the fervor over the annual college basketball tournament comes news of a different kind of spring event: vasectomy season.

According to some news outlets, March Madness is tied to an increase in men getting vasectomies. "March Madness vasectomy season is upon us," one recent headline declared. "Vasectomy Spike linked to March Madness," read another. The thinking is that men schedule their vasectomies to coincide with March Madness, which gives them a legitimate reason to sit on the couch for hours watching games while recovering, according to The New York Times.

But is this a real happening, or just hearsay?

It may be a bit of both.

It appears that there is, indeed, an uptick in vasectomies in the U.S. during March. A 2018 study of vasectomy trends in the U.S. found that most vasectomies are performed in March, as well as during the end-of-year holidays. [5 Myths About the Male Body]

But rather than an organic trend, the uptick in March may have been spurred by media headlines and marketing, experts told Live Science.

It's "an urban legend that led to fact," said Dr. Ajay Nangia, a professor and vice chair of urology at The University of Kansas Health System.

According to Nangia, the origins of the idea trace back to around 2004, when a urologist tried to promote vasectomies during March Madness. News outlets picked up on the idea, which eventually led to more men actually booking vasectomies in March. "It's become self-perpetuating," Nangia told Live Science.

Dr. Sarah Vij, a urologist and assistant professor of surgery at the Cleveland Clinic's Glickman Urological & Kidney Institute, said she saw marketing as playing a role in March vasectomies.

"In recent years, there have been significant marketing efforts around vasectomy during March Madness. Patients have responded very positively to this," Vij told Live Science.

Indeed, Vij's center started marketing vasectomies around March Madness in 2017 and 2018, during which they saw a significant increase in patient volume; and they have increased their available procedure slots to accommodate this rise in interest, she said.

"Urology offices around the country are similarly advertising the benefits of a weekend on the couch watching basketball, recovering from the procedure," Vij said. "March Madness is one of the few sporting events where games are on all day, all weekend — so it's a popular idea." [Sexy Swimmers: 7 Facts About Sperm]

But that doesn't mean that all men who get vasectomies in March are die-hard college basketball fans.

Nangia said he has started asking the vasectomy patients he sees in March whether they booked the procedure to coincide with the NCAA tournament. Most have told him no — March was simply a convenient time. So although Nangia does think some men get vasectomies to coincide with March Madness, he hasn't seen it in his practice.

Dr. Elizabeth Kavaler, a urology specialist at Lenox Hill Hospital in New York, said she hasn't specifically seen a link between March Madness and vasectomies, although she has noted an increase in springtime in general.

"I do think there's an uptick in interest [in vasectomies] at this time of year," Kavaler said. "I don't know if the basketball tournament has anything to do with it, or if it's the spring."

"I've never made the association" between March Madness and vasectomies, she added. Kavaler also noted that other popular sporting events, like the Super Bowl, don't coincide with an increase in vasectomies.

A vasectomy is a surgical procedure to cut the tubes that carry sperm, so that there is no longer sperm in the man's ejaculate. It's considered a permanent form of male birth control, according to Mayo Clinic.

The procedure is quick, taking about 10 minutes, and requires only local anesthesia, Vij said. It's nearly 100 percent effective.

"All men have some scrotal swelling after the procedure, so we do recommend taking it easy for a few days," Vij said.

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• Trying to Conceive: 10 Tips for Men

Originally published on Live Science.

A former NHL player developed a life-threatening infection after a spiky cactus pierced his leg, according to news reports.

Fifty-year-old Lyle Odelein, who retired from the NHL in 2006 after a nearly two-decade career, was playing golf in Arizona in March 2018 when he walked into the rough to retrieve a ball, according to the Pittsburgh Post-Gazette. That's when a "jumping cactus," or a small segment of cactus that detaches easily when it's touched, lodged into his leg. Odelein's friends needed to use a golf club to pull the cactus from his leg, the Post-Gazette reported.

About a week later, Odelein was back at his home near Pittsburgh when he began to experience leg pain and flu-like symptoms. A friend took him to the hospital, where doctors found he had a serious blood infection that likely stemmed from the cactus injury, the Post-Gazette reported.

The type of microorganism that caused Odelein's infection was not reported. In 2017, doctors in Phoenix published a study of "thorn-associated infections," which found that one of the most common causes of infection after thorn injuries was Staphylococcus aureus, a type of bacteria that lives naturally on people's skin. But in rare cases, infections were caused by microorganisms in the environment, such as Nocardia bacteria, which live in water and soil, or Paecilomyces lilacinus, a fungus found in soil.

Odelein's condition worsened, and he needed to be placed in a medically induced coma. The infection had damaged part of Odelein's heart called the aortic valve, and poor blood flow had caused his kidney and liver to fail.

Doctors attempted a risky and rarely performed triple transplant — of the aortic valve, heart and kidney — in order to save his life. "After the case, some people approached me and said, 'I can't believe you did it,'" Dr. Ngoc Thai, a transplant surgeon at Allegheny General Hospital in Pittsburgh, who treated Odelein, told the Post-Gazette. A report of Odelein's case will be published in an upcoming issue of the Journal of Cardiothoracic and Vascular Anesthesia.

Odelein experienced a temporary paralysis after his surgery and needed to undergo a lengthy rehabilitation program to be able to stand and walk again. He is still recovering but hopes to soon return to the golf course, the Post-Gazette said.

Odelein played for the Pittsburgh Penguins during his final NHL season. 

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Originally published on Live Science.

Imagine a summer breeze. What smells are wafting in the wind? It could be the salty smell of the ocean, a burger sizzling on the grill or, if you're poolside, the chemical stench of chlorine.

Of course, chlorine is a necessary element for summer fun; after all, you wouldn't want to take a dip in a swimming pool without it. The chemical helps keep us safe from an otherwise bacteria-filled soup of pool water and pee. (Fun fact: That swimming-pool smell you associate with chlorine isn't actually chlorine at all but a compound called trichloramine, which forms when chlorine reacts with pee and sweat.)

But is chlorine dangerous?

It's true that "too much chlorine can cause a lot of [skin] irritation," said Dr. Ana Duarte, the director of dermatology at Nicklaus Children's Hospital in Miami. But the amounts that are used in swimming pools are typically not a cause for worry, she noted. [How to Fix 9 Common Skin Problems]

An overchlorinated pool, on the other hand, can cause eye irritation, dry out the hair and skin (by stripping them of natural oils), and sometimes cause color-treated hair to turn shades of green, Duarte told Live Science. Because of this, it's important to have the right levels of chlorine in the pool, she said.

Excess chlorine in the pool can sometimes also cause small amounts of vapor to come out of the water, which "can trigger [a person's] asthma," Duarte said, though she noted that she doesn't think this effect is too common.

"Perhaps it could happen in a freshly chlorinated pool or a super-chlorinated [one]," she said. But as overeager swimmers may recall, pools are typically closed right after pool keepers chlorinate the water so that some of those vapors can diffuse, she said. (In high concentrations, chlorine gas is known to be very poisonous. In World War I, for example, chlorine gas was used as a chemical weapon. Inhaling large amounts of the gas is poisonous and could cause what's called a pulmonary edema, or fluid buildup in the lungs, according to the New York State Department of Health.)

Recommendations from a dermatologist

In general, swimmers need not worry about chlorine. "If you're in a pool situation, in general, it's safe," Duarte said. "And if you do get a little bit of minor irritation, you can certainly shower off right after the pool and apply a good moisturizer to replenish some of those natural oils" that the chlorine may have stripped away.

Even if you don't rinse off, the consequences won't be dire, she said: You may end up with a bit of dry skin, or brittleness in your hair.

People who spend a lot of time in the pool, such as competitive swimmers or pool-loving kids, could have more of their natural oils stripped off their skin, in which case moisturizing can be very helpful, Duarte said. She specifically recommended using cream or ointment moisturizers rather than lotions. She also suggested using moisturizers that contain ceramides, which are natural oils in our skin.

To ward off eye irritation while swimming, "you can always wear goggles," she said. "If you don't want to wear the goggles, then maybe [you can use] some lubricating eye drops afterwards."And for sensitive hair, it can sometimes help to pretreat your hair with oil before getting into the water or to wear a swimming cap, Duarte said.

And infants older than a few months need not fear the pool. Following "the immediate period after birth … everybody's skin more or less develops the same quality and the same protective barriers," Duarte said. "So, I think the main thing with small infants is definitely avoiding peak sun hours and enjoying the pool early, and [making] sure the kids have swimming lessons and [that] they're supervised." Those things worry doctors more than the chlorine, she added.

Indeed, perhaps a more pressing concern is that globe of warmth that shines on us day after day. Don't forget to put on sunscreen and make sure you reapply, especially if you're swimming, Duarte said.

Originally published on Live Science.

College football player Shaquem Griffin impressed coaches and fans at an NFL scouting event on Saturday (March 3) when he bench-pressed 225 lbs. (102 kilograms) 20 times. And he did it all without a left hand.

Griffin, 22, lost his left hand when he was 4 years old due to amniotic band syndrome, a rare condition that occurs during fetal development. The exact cause of this condition is unknown, but it's thought to occur when parts of the fetus become entangled in the amniotic sac, or the sac of fluid that surrounds the developing baby, according to the University of California, San Francisco (UCSF).

The amniotic sac has two layers, an outer layer called the chorion and an inner layer called the amnion. It's thought that in cases of amniotic band syndrome, the inner layer of the amniotic sac ruptures and bands of floating tissue from the layer wrap around parts of the fetus — such as fingers, toes or entire limbs — constricting them, UCSF says.

The condition can cause several complications, ranging in seriousness from mild to severe. For example, in mild cases, a child might have a crease on one limb, but this doesn't affect how the limb works, according to Seattle Children's Hospital. In other cases, the bands can reduce blood flow to parts of the body, leading to restricted growth or tissue injury. Babies with the condition may be born missing fingers and toes if these digits are cut off inside the womb (known as congenital amputation), or the children may be born with their digits fused together, Seattle Children's says. [9 Uncommon Conditions That Pregnancy May Bring]

In severe cases, the bands can become wrapped around vital parts, such as the head or umbilical cord, and this can be fatal, according to UCSF.

In Griffin's case, the amniotic strands wrapped around his left wrist, preventing his left hand from developing normally, according to Sports Illustrated. If doctors had attempted to remove the band in the womb, it could have endangered the life of Griffin or his twin brother, Shaquill, Sports Illustrated reported. As a result, Shaquem Griffin was born with a left hand that didn't function properly and was painful to the touch. Doctors amputated his hand in 1999 to relieve this pain.

Now, Shaquem Griffin hopes to be the first player with one hand drafted to the NFL in the modern era, according to ESPN.

At the NFL Scouting Combine, an event at which college players showcase their skills in front of professional coaches, Griffin ran the fastest 40-yard dash for his position (linebacker) of anyone since 2003, according to Sports Illustrated. And for his weight-lifting feat, he used a prosthetic hand to grip the barbell as he pushed out 20 repetitions, smashing his previous best of 11 reps for that weight, according to the NFL.

"I remember when I first started using the prosthetic, I had just the bar and I was shaking all over the place," Griffin told NFL.com. "It's amazing because it just goes to show how much hard work I put in to get this level," he said.

Original article on Live Science.

Consider dropping from the height of a mid-sized building onto hard, packed snow. What would happen to your legs?

Even if you survived, the bones in your legs probably wouldn't. So why doesn't that happen to ski jumpers or, even more astonishingly, freestyle skiers during the "aerials" event?

Here's how the aerials work: Skiers slip at high speed down a steep slope, zip up a ramp and launch themselves — nearly vertically — into the air, tumbling and performing a series of astonishing flips. Then they land on two skis on hard-packed snow and slide to a stop, easy-peasy.

"If you think about when you do a jump — or pretty much any object that we throw or launch into the air — you follow this parabolic trajectory," Gbur told Live Science.It turns out that the trick to landing with your limbs intact is that the aerials jumps and landings aren't perfectly vertical, said Greg Gbur, a professor of physics at the University of North Carolina at Charlotte.

A parabola is a symmetrical curve — steep in the case of aerials jumpers, long and shallow in the case of the ski jump.

"You design the [landing] ramp so that the skiers coming down are basically coming down on a ramp that follows that parabolic trajectory," Gbur said. "When they're first landing, they're more or less going in the same direction that gravity wants to take them."

If you fell straight down, the hard ground would stop your fall all at once. The intense force of that brutal deceleration, distributed unevenly across your body, would smash it to bits.

But landing on the ramp, while likely not gentle, involves a much slower change in momentum for the skiers.

"The ramp is sort of following the same path that they're already going, so they take the impact gradually, as the curve of the slope gradually becomes level," Gbur said.

Originally published on Live Science.

The Olympics are designed to test elite athleticism, at least in the human realm. But what about the animal world? How would Arctic foxes fare in the Winter Olympics, or snowy owls for that matter?

These Arctic animals, and others, are fast flyers and runners, and they hunt prey with deadly accuracy.

Granted, these animals might not follow all the rules (penguins, after all, slide on their bellies, not sleds), but here are seven animals that would excel at the Winter Olympics and likely win a few gold medals while they're at it. [Beasts in Battle: 15 Amazing Animal Recruits in War]

1. Artic fox

The Arctic fox (Vulpes lagopus) would crush any cross-country-skiing competition. This small carnivore has thick fur that helps it survive in weather as cold as minus 50 degrees Fahrenheit (minus 45 degrees Celsius), according to the San Diego Zoo. Its lush tail can curl like a scarf around its body, keeping it warm, the San Diego Zoo added.

These foxes don't use skis to get around, but the fur on their feet gives them traction as they run, acating like a natural snowshoe. In fact, their species name, lagopus, means "hare-footed" in Greek, according to the San Diego Zoo. 

2. Flattie spider

Whenever the web-less spider notices a potential meal, it keeps one leg anchored and spins around until it catches its target.The flattie spider (Selenopidae) can spin much faster than an Olympic figure skater. To be exact, this arachnid can spin around in one-eighth of a second, which is nearly three times faster than the blink of an eye, according to a study published Feb. 12 in the Journal of Experimental Biology.

Just like figure skaters draw their arms closer to their body to spin faster, flattie spiders pull their remaining legs toward themselves, which allows them to spin up to 40 percent faster and nail a perfect landing, with their mouth positioned next to the prey, according to the researchers who conducted the study. You can watch a video of it below.

3. Arctic hare

During ski jumping, Winter Olympic athletes zoom off a ski jump and lean forward, with their skis in a V-shape as they zoom through the air and land at record distances for their respective countries.

We nominate the Arctic hare (Lepus arcticus) for this event, given that the hare can go airborne, too, as it bounds through the snow at speeds as high as 40 mph (64 km/h), according to National Geographic. 

4. Seal

There are few things more intense than speeding down a steep racetrack on a skeleton sled. But a seal probably wouldn't mind. These fin-footed pinnipeds slide all the time on their fat bellies as they enter and exit the water, according to Seals-World. 

5. Penguins

Penguins would make world-class bobsledders. That's because they're epic tobogganers.

Bobsledding became a sport in the late 19th century, when Swiss athletes attached two skeleton sleds together and added a steering mechanism to make a toboggan, according to Olympics.org.

Likewise, penguins plop down on their stomachs and then slide around on the ice and snow, using their feet and wings to guide and push them along. Some penguins glide on their bellies for miles at a time, according to the National Oceanic and Atmospheric Administration. 

6. Crow

Curling is a complex sport rife with rules and tools — including brooms, stones and sliders. It's no leap of the imagination that crows would do exceptionally well … largely because they're so good at making and using tools.

New Caledonian crows, for instance, can fashion hooks from sticks to grab larvae and insects from crevices in logs or branches, Live Science previously reported. The Hawaiian crow is also a medal winner, finding the best sticks to reach food in awkward spots.

We're not sure if these crows would sweep the ice with brooms, but they would certainly sweep the competition if the goal were to use sticks to nab a snack.

7. Snowy owl

The biathlon has roots in Scandinavia, where people hunted on skis with rifles hung over their shoulders, according to Olympics.org.

Snowy owls (Bubo scandiacus) don't ski and shoot, but they do fly with speed and have excellent hearing and vision that help them hunt with lethal accuracy. These owls would stand atop the podium at any animal Olympics, though they'd likely prefer a tasty lemming to a gold medal.

Original article on Live Science.

Whale watchers cruising off the coast of Hawaii came across something that looked like a giant, used tissue floating in the water this month. But you wouldn't want to blow your nose into this wet blob — according to the Pacific Whale Foundation, the goopy mass of floating white matter was a placenta, likely belonging to a humpback whale.

That's a big deal, according to the foundation, because although scientists have long assumed that humpbacks travel to Hawaiian waters to give birth, no such birth has ever been definitively documented. (Whale Trust, another Hawaiian conservation and research group, confirms that claim.)

It's not entirely clear where or when the foundation's boat, called Ocean Journey, came across the placenta. The organization said the time, place and circumstances "surrounding the discovery are still being determined," but in a Facebook post, the group later suggested the discovery happened on the first whalewatch of the day on Saturday — apparently referring to Feb. 10. [In Photos: Tracking Humpback Whales]

"Humpback whale placenta would perhaps be the next best evidence of the birthing process taking place," aside from documenting an actual birth, Pacific Whale Foundation representatives wrote. "Scientists infer that the placenta is easily dislodged after the calf is born, and then simply floats away," they added.

Rosie Williams, a whale researcher and doctoral student at the National Environment Research Council Doctoral Training Partnership in London, said the find is entirely credible based on researchers' understanding of humpback migration patterns.

However, this isn't the first time a whale placenta has been found in Hawaiian waters, she noted in an email to Live Science.

A similar large mass turned up near Hawaii back in 1994 and was confirmed, using hormone analysis, to be a humpback whale placenta. (What's more, the mass was found floating next to a newborn humpback.) This discovery was published in the journal Marine Mammal Science in 1997.

In that study, the researchers noted that the floating portion of the placenta was about 1.2 to 1.5 meters (3.9 to 4.9 feet) long and that the submerged portion was about 2.4 m (7.8 feet) long. The umbilical cord was about 5 centimeters (2 inches) wide and 1.3 m (4.3 feet) long.

Though a whale placenta has been found in Hawaiian waters before, "this is still an exciting discovery, and if samples have been taken, then there is great potential to try and understand more about reproduction in these fascinating animals," Williams said.

The foundation did not immediately return a request from Live Science for more information.

Originally published on Live Science.

As I write this, I'm sitting in a desk chair — the kind that turns. If I kick my legs hard against the floor, again and again, it will spin fast — not figure-skater fast, but fast enough that when I stop and try to stand, the whole world careens sideways, threatening to hurl me into my editor — which I don't think she would appreciate. [Editor's note: This is correct.] I gave it a try a few minutes ago, and the words of this article are still listing queasily even as I type them out.

This isn't surprising, really. Every child discovers sooner or later that if they spin themselves hard enough, the whole world will tumble. But when it comes to elite athletes — and figure skaters, in particular — we can forget that their lithe, talented bodies are subject to the same physical laws as ours. [Can Olympic Figure Skaters Break the 5-Spin Barrier?]

When Mirai Nagasu hurls herself into a whirling triple axel, Nathan Chen hops balletically into the air and turns four times before landing, or Adam Rippon contorts himself through a series of fluid shapes while spinning his way on one skate through long measures of music, their wet inner ears — human beings' motion sensors and the origins of most dizziness — slosh around just the same as mine in that rotating chair (or yours, if you gyrate fast enough).

The difference between Olympic figure skaters and the rest of us, it turns out, is deeper than the inner ear, buried in the brain.

Where dizziness comes from

In our inner ears, there are three fluid-filled tubes called "semicircular canals," said Paul DiZio, a neuroscientist at Brandeis University who studies balance, motion and dizziness. Each one is aligned with a different axis of motion: up and down, left and right, and side to side.

"When you move your head, the fluid inside the tubes kind of flows a little bit," DiZio told Live Science. "And then you've got these sensors — sensors that are like little pieces of seaweed inside the tubes — that kind of float with the fluid and sense what's going on."

Nod your head yes, and the sensors in one set of tubes spark to life. Shake your head no, and another set of tubes sends signals to the brain. Touch your ears to each shoulder, and the final set of sensors activates.

"Normally, the motions we make don't last for too long," DiZio said.

And rotational motion, in particular, tends to occur in short stretches of time — turning to look out the window, leaning your head back to crack your neck, that sort of thing. And our inner ears are built well for tracking that sort of motion.

"That information's helpful for just knowing where we are in the world, and it helps us to keep our eyes stable in the world," DiZio said.

Eye stability turns out to matter a lot for balance and motion sickness, said James Lackner, also a neuroscientist and motion-sickness expert at Brandeis University.

If we can keep our eyes fixed on the world against the spinning of our bodies, we usually don't get nauseous. But when our sense of place and movement gets out of whack, our eyes start to flicker spasmodically as they try to keep up with motion that isn't really happening. DiZio compared the effect to watching a movie filmed by a photographer with shaky hands. And that, Lackner added, is when our gorges rise.

Given those reactions, sustained spinning — which our bodies just aren't built for — is a perfect disruptor of our inner ears and inertial senses, DiZio said.

"If you took a glass of water and put it on a lazy Susan, and you spin it just a little and then you stop it, the water won't be moving," he said. But "if you spin the lazy Susan for a while and then you stop it, the water will have built up some momentum." It will keep moving long after the table stops spinning.

A similar effect happens in my ear when I spin on my office chair. The fluids in my ear pick up enough momentum that they keep sloshing long after I've stopped the chair, sending signals through those little seaweed-like sensors to my brain to say my body is still in motion. My brain tries to correct for that motion, juddering my eyes and urging my body to lean one way or another, and then I start to topple.

Figure skaters exert amazing control over their own senses

Figure skaters like Nagasu, Chen and Rippon aren't immune to these effects; their inner ears don't behave any differently from mine or yours. No one can train those fluids not to obey the laws of inertia.

In the GIF below, Russian skater Evgenia Medvedeva's inner ear is likely whipped into more of a sensory frenzy than most people experience in their entire lives — an effect that's only compounded each time she changes the position of her head, DiZio said.

Put an untrained person through that kind of motion, and they'd come out of it feeling like they were "tumbling through space," with their inner ears signaling ongoing motion along more than one axis, Lackner told Live Science.

That would lead to "a reflex to kind of throw yourself in the other direction, and throw yourself off-balance," DiZio said.

And that's not a reflex a skater balancing on one blade can afford.

The first step to overcoming it, DiZio said, is to habituate the brain to the sensation of dizzy motion.

Habituation is a trick the brain does all the time, to avoid being constantly overcome by sensations. "It's like if you start eating something sweet, and you eat it for a while, it doesn't taste as sweet," DiZio said.

But to prepare for Olympic-level high-speed spinning, figure skaters need to adjust to an entire set of sensory inputs. That's a bit tougher than adjusting to an oversweetened slice of cheesecake, or gradually lowering yourself into a pool of frigid water.

DiZio and Lackner understand the process because they've done similar experiments on people who need to control dizziness in other contexts, like potential astronauts and patients with damaged inner ears that send constant, vertigo-inducing dizzy signals to the brain. Brandeis University even has a large room that can spin fast enough to induce seven times the force of Earth's gravity, Lackner said, though they rarely subject their subjects to more than two times the planet's force.

Here's what it comes down to: "Practice — practice over and over and over," DiZio said. [Why Is It So Easy to Cheat at The Olympics?]

In vertigo patients, Lackner said, that practice involves all sorts of head-twisting exercises. For figure skaters, the process is more straightforward.

"Do the spins. They start out with just one or two spins and build up, and they work out, too," DiZio said.

At about 44 seconds into the video below, Nagasu straps herself into a device, which one of her coaches then uses to lift and rapidly spin her. That's a harsh assault on the inner ear — one that takes lots of repetition to tune out. And even then, the training isn't perfect.

Ever wonder what training looks like for an Olympic figure skater?@mirai_nagasu shows us what it takes to be among the world’s elite. pic.twitter.com/AtNQy3F9Ly

— The Players' Tribune (@PlayersTribune) February 9, 2018

"You can't 100-percent habituate," DiZio said. Even the most trained skater will still feel some of the disorientation of a long, twisting doughnut spin.

That's where some more subtle tricks can help.

Slate reported in 2014 that skaters' coaches tell them to come out of a spin with their eyes locked on a landmark.

DiZio said that makes sense from a neuroscientific perspective. After a long spin, he said, "the inner ear is kind of reflexively driving the eyes in a way that's going to mess up vision, and if you're already dizzy and your vision gets blurry, you're kind of lost."

By picking landmarks to focus on after each spin in advance, DiZio said, skaters can fix their sight lines after spinning to locate themselves in space. That way, "even if the inner ear is giving them messed-up information, at least the eyes are helping them out," he said.

Another wild possibility

But DiZio, after watching lots of figure skaters at the Olympics, thinks he's landed on another reason skaters don't tip over, retching after each performance.

"This is my theory — to tell you the truth, I haven't seen this anywhere — but I think at least 80 percent of the time when the person does the spin and they stop, they don't just stop solid and make no movement. They do like a little dance motion at the end in which they dip their head," he said.

That could, consciously or unconsciously, be an effort to take advantage of sensory "dumping," effectively hacking the way the brain handles information.

Here's how it might work, as DiZio explained it:

All the information from the inner ear enters the brain through what amounts to a relay center and amplifier. Nerves twist around on themselves, causing the signal "Spinning! Spinning!" to reverberate louder and louder in the brain so it can reach all the relevant systems. And that "Spinning!" signal is routed along the exact same pathways used to tell the rest of the brain how the body is oriented relative to the constant force of gravity.

Dip the head, jolting the apparent direction of gravity, and that signal will travel to the same relay center already firing off "Spinning!" signals. Given limited resources, the relay "dumps" the spinning signal from its amplifiers to make room for a new signal: "Jolted! Jolted!"

"Again, I've never seen that [written] anywhere," DiZio said. "But it looks to me like skaters work into their routine a little movement at the end that doesn't look like it's an accident. Conscious or unconscious, they make it part of their routine."

Lackner confirmed that sensory dumping is a real effect but said he's skeptical that skaters are deploying it in their choreography.

"My guess is that isn't a big deal in skaters because they have gone through such a process of habituation to start with," he said.

Regardless of whether medal-winning skaters actually unconsciously play with their sensory relays in the way DiZio speculates, the mental workout they go through to prepare for their routines seem at least as Olympian as their physical preparations.

Originally published on Live Science.

Olympic audiences went wild last week when Mirai Nagasu landed a triple axel, becoming the first U.S. female figure skater to turn an entire 3.5 rotations in the air at the Winter Games.

Meanwhile, male figure skaters have mastered the quadruple jump, that is, four rotations in the air. But no skater, male or female, has pulled off a quintuple-turn jump.

What gives? And more importantly, is it possible? [Photos: 6 Failed Winter Olympic Sports]

"I'm in the camp that I'm doubtful that that will happen," said Jim Richards, a professor of biomechanics in the Department of Kinesiology and Applied Physiology at the University of Delaware. But other human-biomechanics experts are more optimistic.

"I am a person who leans toward the 'yes' side," said Deborah King, a professor in the Department of Exercise and Sport Sciences at Ithaca College, in New York. Figure skaters could achieve a quintuple-turn jump if they perfected the key components involved in a rotation, she told Live Science.

When skaters leave the ice, they need angular momentum — that is, rotational energy that determines how fast and how much the skaters spin. Once they're in the air, they need to utilize that angular momentum by making themselves into a symmetrical, straight line — crossing their arms over their chests and crossing their legs and ankles — so that they can spin faster. By pulling in their arms, skaters bring their bodies' masses closer to the axis of rotation, something that causes the posh-sounding physics term "moment of inertia" to decrease. Essentially, the moment of inertia works against angular momentum (the spin). Result? The skater spins faster.

In addition, the time they spend in the air depends on their jump height. The higher they jump, the more time they'll have for revolutions before the anxiously awaited landing back on the ice, the experts said.

In general, female skaters tend to jump between 15 inches and 20 inches (38 and 51 centimeters) and men usually jump between 20 inches and 23 inches (51 and 58 cm) vertically off the ice, Richards said.

Most skaters have perfected these components, King said. "They already have their limbs entirely plastered against the body, and they are as narrow as they could possibly get [during the jump]," she said. But some have room for improvement; their arms are crossed, but their elbows are sticking out, or their ankles are crossed, but their knees are separated an inch or two, she noted.

These athletes have "a couple inches of room to get tighter," King said. "From a physics standpoint, that's going to make them rotate a little bit faster."

Granted, the skaters would have to train themselves to get used to a faster rotation. Moreover, the faster they spin, the greater the centripetal force, which makes it feel like their arms are being pushed away from their body. "They have to use the muscles of their arms and legs to squeeze in tightly, and that actually takes a tremendous amount of strength, because they're going so fast," King said. [Winter Warriors: The Fitness Skills of 9 Olympic Sports]

If skaters can master the extra spinning and its increased forces, they could turn about an extra 100 degrees or 120 degrees, about an extra third of a 360-degree rotation, King said. So, to get closer to a full rotation, the skaters would have to train to jump even higher than usual — maybe another 2 inches (5 cm), which could give them another 60 degrees of rotation, King said. Even more practice could bring them to an extra 270 degrees, she said.  

"That's three-quarters of a revolution," King said. "It's technically not a five-revolution jump. If they were doing it in competition, it would probably be downgraded because it's not totally rotated."

But it would still be an extraordinary feat, and it would be more than a 4.5-rotation, which has never been pulled off in a competition, she said. However, King noted that skaters would need the right body type — basically a small body that can spin quickly but that is also powerful enough to get a good jump height.

Richards agreed. It is possible that a five-rotation jump could be pulled off, if the right person trained enough, he said.

"It might be one person, but I don't see it happening on a wide scale," Richards told Live Science.

Original article on Live Science.

Today (Feb. 13), Japanese short-track speed skater Kei Saito became the first Olympic athlete to be suspended from the 2018 Winter Games due to doping allegations. According to the Court of Arbitration for Sport (CAS), Saito tested positive for a diuretic called acetazolamide, which can be taken to hide the presence of performance-enhancing drugs and is one of more than 200 chemicals prohibited by the World Anti-Doping Agency.

Saito's suspension is the first to occur during the 2018 games, but it's hardly the first scent of doping-related scandal this winter. Just days before Saito's expulsion, the CAS ruled to uphold the bans on 47 Russian athletes and coaches implicated in a state-sponsored doping program during the 2014 Winter Olympics in Sochi, Russia.

The actual rate of doping among Olympic athletes, however, is thought to be far greater than even scandals like these indicate. [10 Biggest Doping Scandals in Olympic History]

"As evidenced by athletes who were previously thought to be clean and weren't, people are willing and able to dope at large scale," said Thomas Hildebrandt, a performance-enhancement researcher and associate professor of psychiatry at the Icahn School of Medicine at Mount Sinai in New York City. "I think we have to assume that the Russians got caught but other programs are doing similar things. And I think it would be foolish of anyone to think otherwise."

How widespread is Olympic doping?

The World Anti-Doping Agency (WADA) tests blood and urine samples from several hundred thousand Olympic athletes every year. About 1 to 2 percent of these samples test positive for prohibited substances, but actual instances of doping are estimated to be significantly more widespread. In one anonymous survey of several thousand world-class amateur athletes, up to 57 percent admitted to using performance-enhancing drugs in the past year, according to a study published in the journal Sports Medicine.

WADA said that results like these suggest that many tens of thousands of athletes may be getting away with behavior that, for better or worse, is considered cheating. But why is it so easy to cheat this system?

"The big problem of testing is the timing," Hildebrandt said. "You have to time the test correctly to detect the substance."

Olympic athletes can be tested at any time — potentially even years in advance of the next competition, Hildebrandt said. But because drug tests are so expensive to conduct, most of these evaluations are administered much closer to when the actual competitions occur, he said.

Athletes and coaches are aware of this, "and a lot of athletes get done with their doping before they're at high risk for testing," Hildebrandt said. Drugs taken in small doses during the off-season can be almost impossible to detect in urine samples a year or more later, but the performance-enhancing effects remain, he said.

"You can build muscle and keep it," Hildebrandt said. "Athletes can make physical gains in times when they're not under much suspicion or would be unlikely to be tested at high frequency. So, they can walk into the games and honestly think, 'I'm clean,' have no drugs actually in their system, but have gotten to the place where they're at physically with other help along the way."

A step behind the steroids

Beyond clever timing, athletes also have the ongoing evolution of doping drugs on their side: WADA officials cannot test for a performance-enhancing drug they've never seen before. Because of this, "the ability to beat doping tests continues to evolve, and the test will always be one step behind the perpetrators," Hildebrandt said.

As an example, Hildebrandt pointed to anabolic steroids — the most common form of performance-enhancing substance among athletes, according to a 2017 WADA report. Steroids primarily target the body's androgen receptors, which bind with hormones such as testosterone to facilitate muscle growth, among other things.

However, "there are atleast 500 known chemicals that can target the androgen receptor [and] that can be made in a basic chemistry lab," Hildebrandt said."Someone who's smart, motivated and knows a lot about chemistry can find all kinds of creative ways to target that receptor with a substance that doesn't show up on the traditional test — because [officials] have to know a drug exists before they go looking for it."

Over time, drug tests do catch up with the drugs themselves, resulting in expensive scandal investigations and relatively small groups of athletes losing their medals years after competing. (This can happen because labs will often save a small sample of an athlete's blood for later testing, Live Science reported in 2016.) In the meantime, Hildebrandt said, many other athletes may get away with using performance-enhancing drugs by taking low doses at times when they are unlikely to be tested.

"As that pattern persists," Hildebrandt said, "you will continue to have people who are willing to take the risks to game the system."

Originally published on Live Science.

How do Olympic athletes' diets and exercise regimens affect their performance … in the bathroom?

Olympians-in-training undergo intense and prolonged exercise routines, often accompanied by specific dietary requirements. But studies have shown that these practices — especially in endurance sports, such as marathon running — can have adverse effects on the body and, in particular, on the gastrointestinal (GI) system.

Researchers have found that rigorous training can not only lead to nausea, abdominal pain and diarrhea, among other physical symptoms, but also affect the bacterial communities living in the gut, which can carry additional implications for an individual's health, experts told Live Science. [The Poop on Pooping: 5 Misconceptions Explained]

Perhaps the most extreme — and famous — example of an Olympian experiencing severe gastric distress midperformance is French racewalker Yohann Diniz. While competing in the 50-kilometer (30 miles) walk final at the 2016 Olympic Games in Rio de Janeiro, Diniz collapsed with what appeared to be blood and feces running down his legs — though he still managed to finish the race in seventh place, Business Insider reported.

Pain in the gut

Gut distress is, in fact, "very common" among endurance athletes, with an estimated 30 to 50 percent of long-distance runners experiencing some degree of GI problems, according to a review published in May 2014 in the journal Sports Medicine.

In another study, heavy exercise was found to affect digestion in subjects who were "well-trained athletes," with intense workouts increasing the participants' stool frequency and affecting its consistency, scientists reported in March 2011 in the Scandinavian Journal of Gastroenterology.

Stress generated by endurance training or extreme exercise can produce an inflammatory response in the gut, which can lead to diarrhea, bloating and abdominal pain, Kim Barrett, a distinguished professor of medicine at the University of California, San Diego, told Live Science. Endurance training also diverts oxygen flow from the gut to the muscles, which can disrupt healthy GI function, Barrett said.

"The gut doesn't have enough oxygen, and that can cause injury to the lining of the bowel," she said.

Serious diarrheal symptoms can also lead to dehydration, which will not only affect an athlete's performance but can have serious health consequences as well, Barrett said.

Not only runners

While gastric stress is widely recognized as the bane of long-distance runners, far less is known about the extent of GI symptoms in other athletes, such as hard-training Olympians, and the problem may be more widespread than previously suspected, scientists reported in an editorial published in October 2017 in the British Journal of Sports Medicine.

The researchers surveyed 249 "elite athletes" from sports that included cycling, horse racing, rugby, tae kwon do and ultramarathon running. They found that 86 percent of their subjects described at least one GI symptom, and 15 percent described one symptom — and sometimes more — as being "moderately severe" or worse. About 48 percent reported abdominal bloating, 44 percent described gassiness and 21 percent noted the presence of diarrhea.

Such a high prevalence of symptoms suggests that health professionals should take a closer look at how the gut is affected by intense training and dietary practices across a range of athletic disciplines, the scientists concluded.

Meddling with the microbiome

Athletic training may also bring changes that affect the microbes in the digestive system, and the change in gut microbes may actually benefit the athlete, Barrett noted.

"In athletes of all stripes, there's a positive effect where the microbiota appears to change in a way that makes it more diverse, and there's also an increased representation of microbes that harvest energy from the diet," she said.

According to a review article published in March 2017 in the journal Oxidative Medicine and Cellular Longevity, exercise can increase gut microbial diversity and encourage beneficial microbes to flourish. In particular, exercise promotes a beneficial balance between populations of two gut microbe groups: the genus Bacteroides and the phylum Firmicutes. Imbalances between these groups have been linked to certain GI disorders and obesity, the review authors wrote.

However, far more research will be required in order to uncover the ways athletic training changes the gut microbiome and how these shifts in the microbial balance affect athletes' metabolism — and perhaps their performance, Barrett told Live Science.

"The flip side of this is, are the microbes doing anything that benefits the exercise?" Barrett said.

"Clearly, there's communication between the brain and the gut — beneficial effects of microbes on exercise could be related to changes in mood and cognition," she said.

"There are some very preliminary studies in mice showing that if you change the microbes in their guts, they can endure longer exercise bouts — but that's only in animals at this point," Barrett said.

Original article on Live Science.

A lizard with no lungs, a deer with vampire fangs and a little black bird carrying around human baby teeth in its beak all walk into a country.

This is no joke set-up — this is a real snapshot of the eccentric biodiversity of South Korea (well, except maybe for the baby teeth thing… more on that in a minute).

As the 2018 Winter Games unfold in Pyeongchang, can the viewing public count on any surprise animal cameos akin to the 30 or 40 dog-size rodents called capybaras that invaded the golf links during the 2016 Olympic Games in Rio de Janeiro? Live Science investigated the funkiest fauna of the Korean Peninsula and compiled this list of the likeliest suspects.

Musk deer

Any Olympians who wander too far into the forested hills outside Pyeongchang might come home with horror stories about the smelly, vampire-fanged denizens of the woods. Male Siberian musk deer (Moschus moschiferus) may look fierce with their saber teeth, but they're actually harmless herbivores. "The males have these long sabers to fight each other during the mating season," Jack Tseng, a paleontologist at the American Museum of Natural History, previously told Live Science.

In fact, musk deer, which are native to mountainous habitats around Asia and Russia, have far more to fear from humans than the other way around: Male deer are routinely poached for their eponymous scent glands, which can be worth nearly $20,455 per pound ($45,000 per kilogram) on the black market, according to the International Union for Conservation of Nature (IUCN). In 2016, South Korean researchers started work on cloning the musk deer to save the species from extinction.

Korean magpie

The Korean magpie (Pica pica sericea) is a stocky, black, crow-like bird with a white belly and blue-striped wings. Korean magpies are popular enough in South Korea to land a spot on the Google Doodle inaugurating this year's Winter Games — but these little black birds have had a foothold in culture for a lot longer than Google has been around. Magpies are a common symbol of luck in Korean folklore, and they sometimes even fill in for the tooth fairy. Some Korean children reportedly learn to throw their baby teeth onto the roofs of their homes so that a magpie will fly off with the discarded chompers and bring back healthy new ones in their place.

Despite their folkloric reputation, magpies probably don't take kindly to repeated projectile tooth attacks. According to a 2011 study, Korean magpies can learn to recognize individual human faces and remember which individuals have posed a threat to the safety of their nests.

White-naped crane

White-naped cranes (Antigone vipio) are elegant, endangered and apt to spend winter in the Korean Demilitarized Zone (DMZ) between North and South Korea. In other words, they're the perfect symbol of peace on the Korean Peninsula.

The species takes its name from the white stripe running down the back of its neck, but it might be more striking for the vivid red patches around its eyes. According to the International Crane Foundation, white-naped cranes breed primarily in northeastern China and Mongolia, but several hundred birds fly south to the Korean DMZ every winter. (Thousands of others continue on to one of several artificial feeding stations in Japan.) This Korean stopover may be critical to the species' survival, the IUCN says. Due to the ongoing loss of their wetland breeding grounds to human activities, the cranes are listed as vulnerable by the IUCN.

Wild boar

You might not expect the king of the mountain predators to oink, but according to reports from the Seoul Metropolitan Fire and Disaster Headquarters, wild boars (Sus scrofa) are "now at the top of the food chain in Korea."

The scruffy swine spend most of their time in mountain ecosystems, but in recent years, they have become increasingly comfortable venturing down into cities. Wild-boar sightings in Seoul, for example, have increased 11-fold, from 56 city sightings in 2012 to 623 in 2016, the Seoul Metropolitan Fire and Disaster Headquarters said, mostly occurring between September and December, when there is less food available in the hills. As natural predators like tigers have become extinct from Korea, boars thrive — and that's making human-boar interactions more common than ever.

Lungless salamander

Meanwhile, lurking under a nearby rock, a lungless salamander breathes through its skin. The Korean crevice salamander (Karsenia koreana) was only discovered in 2003, and scientists still don't know much about it. The critter mostly keeps to itself underneath rocks in limestone forests and bears a lot of similarities to the North American lungless salamander family, also called Plethodontidae, which comprises most of the world's salamander species. So far, K. koreana is the only lungless salamander to have been detected in Asia, but it was probably once just one among many others that are now extinct, researchers believe.

"The habitats in Asia are appropriate for these animals — so it is strange that they became extinct there and not here," David Wake, a biologist and salamander expert at the University of California, Berkeley, previously told Live Science.

In other words: Amphibian enthusiasts hoping to see more lungless salamanders on the Korean Peninsula probably shouldn't hold their breath.

Originally published on Live Science.

A nasty stomach bug is spreading at the 2018 Winter Olympics, according to news reports.

As of yesterday (Feb. 8), 128 cases of norovirus — a highly contagious infection that causes vomiting and diarrhea — were confirmed at Olympic sites, according to the Korea Centers for Disease Control and Prevention.

In the U.S., there are 19 million to 21 million cases of norovirus each year, on average, the U.S. Centers for Disease Control and Prevention (CDC) says.

As Live Science has previously reported, the virus can spread very easily, in part, because its symptoms come on so quickly. That means that a person may start vomiting in places where they normally wouldn't, spreading virus particles around. [27 Devastating Infectious Diseases]

And norovirus particles can survive for days outside the body.

Indeed, some characteristics of norovirus have led one expert to deem it the "perfect human pathogen."

"These viruses possess essentially all of the attributes of an ideal infectious agent: highly contagious, rapidly and prolifically shed, constantly evolving, evoking limited immunity and only moderately virulent, allowing most of those infected to fully recover, thereby maintaining a large susceptible pool of hosts," Dr. Aron Hall, an epidemiologist on the viral gastroenteritis team at the CDC, wrote in a 2012 editorial published in The Journal of Infectious Diseases.

In other words, the virus spreads easily and rapidly. It constantly evolves to evade the body's immune system. And it doesn't kill people, instead getting them sick enough to spread the virus further and then recover to live another day as a potential host. 

In the editorial, Hall noted several characteristics that make norovirus so formidable. First, it takes as few as 18 viral particles to make a person sick — a tiny amount, considering that a sick person can shed up to 5 billion viral particles in a single gram of feces, Hall wrote.

Next, in addition to being able to survive lengthy stints outside the human body, norovirus particles can withstand harsh conditions, Hall wrote, including freezing, some heating and many common chemical disinfectants. What's more, there are many ways that norovirus can spread, including by ingesting contaminated food or water, handling contaminated objects and ingesting aerosolized particles, he wrote.

Finally, because noroviruses rapidly evolve, people are unlikely to build up an immunity to the virus, meaning they can get infected once again, Hall wrote.

Originally published on Live Science.

Olympic participants are generally muscular and fit, physically primed by years of training to perform on the international stage. However, two notable exceptions this year are rotund, squishy and a little clumsy, and they won't be winning any medals for their athletic prowess.

Nevertheless, they serve as iconic emblems of the Winter Games and of the culture and folklore of the Olympics' host country, South Korea. They are the official Olympic mascots — a white tiger named Soohorang, representing the 2018 Winter Games, and an Asiatic black bear named Bandabi, serving as the mascot for the 2018 Paralympics.

Visualized cartoonishly, these anthropomorphized animals are tubby and smiling and deliberately cute. But the Asiatic bear and white tiger also have a long and storied past in the Korean peninsula, appearing as pivotal figures in its culture and history, and featured prominently in paintings and sculptures. [Iconic Cats: All 9 Subspecies of Tigers]

Both animals appear in Korea's origin story, according to the "Samguk Yusa," or "Memorabilia of the Three Kingdoms," a collection of Korean historical accounts, legends and folktales dating to the 13th century. In the tale, a bear and a tiger undergo a series of grueling trials to become human. The tiger fails, but the bear triumphs and is transformed into a woman, later giving birth to Korea's founder, according to the legend.

Olympic mascots are often animals that are representative of the host countries — but not always. The very first mascot, nicknamed Schuss and appearing unofficially at the 1968 Olympics in Grenoble, France, was a red ball topping an S-shaped, blue and armless body, balanced on what appeared to be a set of skis, according to the International Olympic Committee (IOC).

The 2012 London Summer Games mascots, Wenlock and Mandeville, were even weirder. Wenlock was a metallic being whose body was born of the steel left over from building the London Olympic Stadium, according to the IOC. A light on Wenlock's head was borrowed from the iconic London cab, and his giant, cyclopean eyes were meant to represent camera lenses "filming everything," the IOC reported.

The Pyeongchang Organizing Committee for the 2018 Olympic and Paralympic Winter Games (POCOG) introduced Soohorang and Bandabi to the world in an online statement in June 2016. The white tiger is thought to be a sacred guardian animal, a role that is mirrored in part of Soohorang's name — "Sooho," which means "protection" in Korean, according to the statement.

"The tiger is one of the most familiar animals in Korea, appearing in art and literature from ancient times till today," Bae Ki-dong, director of the National Museum of Korea, recently told The Korea Times.

White tigers are a variant of the Bengal tiger (Panthera tigris tigris), and their unusual coloring can be traced to a mutation in a single pigment gene. However, they haven't been seen in the wild since 1958, Live Science previously reported.

South Korea was home to Siberian tigers, also known as Amur tigers, and the big cats were once widespread in Korea, Bali, Indonesia and China. Now, however, they are found primarily in eastern Russia, with small populations in China and North Korea, according to National Geographic. It is unclear when tigers disappeared from the southern part of the Korean Peninsula, though one account describes the killing of "the last Korean tiger" in 1921 in the coastal city of Gyeongju, South Korea, The Seoul Times reported.

Asiatic black bears (Ursus thibetanus), also called moon bears, symbolize courage and strength in Korean culture, and the first part of Bandabi's name comes from "bandal" — or "half-moon" — referring to the trademark white crescent design on the bear's chest, POCOG representatives said in the statement.

The species is widely distributed in Asia, but in South Korea, the bears were hunted nearly to extinction by the beginning of the 21st century, according to the International Union for Conservation of Nature and Natural Resources (IUCN). A reintroduction program helped to boost their numbers, and by 2015, approximately 40 bears were living in South Korea's Jirisan National Park, the IUCN reported.

As it happens, Soohorang is not the first tiger to represent the Republic of Korea as an Olympic mascot. During the 1988 Summer Olympics in Seoul, an orange Amur tiger named Hodori — a combination of the Korean words "ho" for "tiger" and "dori," a word for boys —held the place of honor, the IOC reported.

Original article on Live Science.

There's an added challenge at the 2018 Winter Olympics, according to news reports: an outbreak of norovirus.

More than 40 security guards have fallen ill with the stomach bug, The Washington Post reported yesterday (Feb. 6). In an effort to stop the spread of the virus, more than 1,200 people have been quarantined while they are tested for the disease, according to the Post.

The highly contagious stomach virus, which causes diarrhea and vomiting, is notorious for spreading easily at close-quarter events, Live Science previously reported, including on cruise ships and at conventions.

One reason that norovirus is so contagious is that the symptoms — including vomiting — come on very quickly, Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security in Baltimore, told Live Science in 2016. That means that people may vomit in places they normally wouldn't, thereby spreading virus particles to others, Adalja said.

What's more, these particles can survive for days outside the body, he added.

And it doesn't take much to get a person sick: Coming into contact with as few as 18 norovirus particles can make a person ill, according to the Centers for Disease Control and Prevention (CDC). Once infected, a person can shed billions of these particles, the CDC says.

The Pyeongchang Organizing Committee is investigating the source of the virus and how it spread, according to The Washington Post. The security guards who fell ill were all staying at a youth center in the mountains near Pyeongchang, the Post said.

Read more at The Washington Post.

Originally published on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

During the second quarter of Super Bowl LII, the party stopped, if just for a second.

Tom Brady found Patriots wide receiver Brandin Cooks downfield with a 23-yard completion. Cooks spun around then got laid out by the Eagles' Malcolm Jenkins, who was going full speed, leading with his shoulder.

Right in the middle of football's biggest game, there it was: another reminder of the NFL's concussion crisis. NBC commentators Cris Collinsworth and Al Michaels seemed to struggle with the fact that the play was legal.

That's where we are these days. No one knew quite what to say as Cooks looked like he had been knocked out by an absolutely routine part of the game, which sidelined him for the night.

For all that, I doubt the uncomfortable few minutes while he was treated on the field – viewers had no idea how badly he was hurt – caused more than a few fans to turn away. Based on my experience as a sports editor, my hunch is most of the tens of millions who watched had already come to terms with the game's violence.

Concussions and football

The problem of head injuries in football has gotten widespread attention over the last decade.

In 2015, for example, Will Smith's "Concussion" chronicled the work of Dr. Bennet Omalu, who identified the prevalence of chronic traumatic encephalopathy, or CTE, in football players. A Newsweek headline at the time asked: "Can a Will Smith movie change the way America views football?"

The answer then was no, in part because the movie's box-office performance was meh.

If fans and commentators ask a similar question today – can the concussion problem put football out of business? – the answer would still be no, but a qualified one. The health risks of the game aren't enough on their own to kill the sport.

Americans still (mostly) love football

There are two reasons why football won't go out of existence, despite a consistent flow of head injuries.

The first is popularity and the financial strength it yields.

While Super Bowl ratings were down, Philadelphia's thrilling 41-33 upset of New England still drew 103.4 million American viewers. That makes it the 10th most watched event in television history, behind eight other Super Bowls and the final episode of "M.A.S.H."

Not only that, the NFL dominates TV ratings all year. Little wonder league revenue has almost doubled this decade, to roughly $14 billion. The NFL is shooting for $25 billion by 2027.

Smoking, drunk driving and … football?

That leads to the second point.

The implication of that Newsweek headline is an argument that goes like this: "If fans only understood the dangers of concussions, they would turn against football, as they did against smoking or drunk driving."

But the issue is not about awareness. The New York Times reported powerfully on it as early as 2007, and a Frontline documentary in 2013 sparked a national discussion. While there is definite concern, as polling data show, most fans haven't been ready to pull the plug – at least not for that reason.

It's the same for players. The Associated Press interviewed 100 a couple of seasons ago and found only 39 were more worried about the long-term effects of concussions than other injuries.

Maybe it's this simple: We've always known football was risky, and now we know more about what that means. But if everyone knows the risks involved, then everyone should be free to do and watch what they like. There are other examples of sports and activities in a similar vein – motor racing, hockey and boxing, to name a few.

Behind the decline

Still, the NFL has undeniably suffered a ratings decline.

There are several reasons for this, from the erosion of cable television, to controversies such as what constitutes a catch, to the National Anthem protests that prompted the president to attack the NFL. I asked a class of 15 students recently if they knew someone who stopped watching because of players taking a knee. Five raised their hands, something confirmed by national surveys.

The bottom line: Head injuries don't appear to be behind the ratings drop. And it could reverse in an instant, perhaps by a Supreme Court decision legalizing sports betting. That's all it might take to boost fan interest and the league's bottom line – with $25 billion around the corner.

John Affleck, Knight Chair in Sports Journalism and Society, Pennsylvania State University

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

WARNING: This article contains spoilers for a future live sporting event, assuming that you accept that a 1-year-old hippo has the power to violate all known laws of time and space.

Fiona the hippo has determined that the Philadelphia Eagles will win the 2018 Super Bowl, and she communicated her determination to humanity by eating a bit of lettuce. This is science.

Fiona, a 1-year-old baby hippopotamus, was the first of her species born at the Cincinnati Zoo in 75 years and the first hippo ever imaged with an ultrasound before birth. She was born 6 weeks premature, and at just 29 lbs. (13 kilograms), was the smallest baby hippo ever to survive. It's unclear which of these traits imbued Fiona with the ability to cast her consciousness forward through time and return with the results of major sporting events. But that appears to be what happened, as demonstrated in this video released by the Cincinnati Zoo:

Fiona approached two cardboard boxes, one painted Philadelphia Eagles green and the other New England Patriots red, white and blue. Each container had a couple of leaves of lettuce scattered on top.

Fiona approached the Eagles box first. Then, like, any good performer, she built tension by munching some lettuce on the ground and feinting toward the Patriots box. But she munched the lettuce first off the top of the Eagles box, revealing to the world which team will win the 2018 Super Bowl. [Is Time Travel Possible?]

Fiona joins the ranks of several other animals who can apparently transcend the known limitations of this universe and who have chosen to lend that skill to human betting markets: Paul the World Cup-predicting octopus, Sonny Wool the "socially inept" rugby-predicting sheep, Yowie the Super Bowl-predicting Australian cattle dog and many others.

No word yet from Fiona on whether the 2018 Super Bowl will include any major concussions or other devastating injuries on the road to the now-inevitable Eagles win.

Originally published on Live Science.

Swimming dinosaur

About 75 million years ago, an odd dinosaur walked from land into the water, where it used its flipper-like arms to swim in the ocean. This amazing feat was rare, as most dinosaurs of its kind could not swim that well, with the exception of Spinosaurus. A fossilized specimen of this enigmatic species was uncovered and sold on the black market for years before researchers could study it. However, not everyone is convinced it's a genuine specimen, and say that it might be a fake. But the researches of a new study say it's real, and even put it in the European Synchrotron Radiation Facility to guarantee its validity.

[Read the full story about the swan-necked dinosaur]

Back to life

A reconstruction of the Halszkaraptor escuilliei, a small dinosaur related to the Velociraptor, exhibits how its body shape and inferred lifestyle make it more closely related to modern waterbirds like swans than to its predator cousins.

3D masterpiece

A 3D rendering of the H. escuilliei calculated from data gathered from the European Synchrotron Radiation Facility's (ESRF) BM05 beamline.

Work in progress

From left to right, paleontologists Pascal Godefroit, Andrea Cau and Paul Tafforeau set up the H. escuilliei fossil.

Getting ready

Part of the ESRF team that worked to research the H. escuilliei fossil helps to set it up for testing at the ESRF BM05 beamline.

Exquisite details

Paleontologists with the ESRF examine the H. escuilliei fossil before testing at the BM05 beamline.

Stellar team

The BM05 beamline team at the ESRF, made up of Pascal Godefroit, Vincent Beyrand, Dennis Voeten, Paul Tafforeau, Vincent Fernandez and Andrea Cau pose with the H. escuilliei fossil.

[Read the full story on Live Science]

New knowledge

At the ESRF tomography beamline, the H. escuilliei fossil represents the first of a new group of semiaquatic predators.

Improved understanding

The H. escuilliei fossil sheds new light on the lifestyle of raptorial dinosaurs.

Mongolian find

The Halszkaraptor escuilliei fossil, which the team nicknamed Halska, was uncovered in Ukhaa Tolgod, in Mongolia.

Deep discussion

ESRF team members Vincent Fernandez and Dennis Voeten discuss the strength of the fossil as they view a 3D representation of the fossils.

Strange snout

ESRF team members analyze the H. escuilliei fossil snout, trying to understand its design.

The facility

Located outside Grenoble, France, the ESRF is a leading facility for the high-quality X-ray imaging of precious items such as fossils.

[Read the full story about the swan-necked dinosaur]

An enigmatic dinosaur — which sported a swan-like neck, amphibious flippers and Velociraptor-esque claws — could walk like a duck and swim like a penguin during its heyday on Earth, scientists have found after examining its fossilized remains.

In fact, the remains, which were on the black market for years, painted such a wacky image of a dinosaur that paleontologists thought it was a sophisticated fake at first. [See images of the swan-necked, amphibious dinosaur]

Its discovery reveals that the bird-like dinosaur was likely semiaquatic and felt right at home in the water, the researchers said. This is surprising because the newfound species is a theropod — a group of bipedal, mostly meat-eating dinosaurs that includes Tyrannosaurus rex — and it's thought that most theropods didn't spend much time in the water, the researchers said. (The major exception being Spinosaurus. Also, T. rex could likely swim, fossilized underwater footprints show.)

The newly identified species likely swam with its flipper-like arms, and its long neck likely helped it with foraging and ambush hunting, the researchers said.

Black market

The newfound dinosaur hails from Ukhaa Tolgod, a dinosaur graveyard in southern Mongolia. Researchers named it Halszkaraptor escuilliei, or "Halszka" for short, honoring Halszka Osmólska (1930-2008), a Polish paleontologist who specialized in Mongolian dinosaurs. The species name honors François Escuillié, who returned the poached specimen to Mongolia, the researchers wrote in the study.

"Illegally exported from Mongolia, Halszka resided in private collections around the world before it was acquired in 2015 and offered to paleontologists for study and to prepare its return to Mongolia," study senior researcher Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels, said in a statement.

Once H. escuilliei was safely delivered to scientists, they set about analyzing it. But the bizarre dinosaur didn't fit into any of the predatory dinosaur groups known from Mongolia. Rather, it had a mix of reptilian, avian and amphibian characteristics. It even had sickle-like "killer claws" on its feet, like those of Velociraptor, the researchers noted.

"The first time I examined the specimen, I even questioned whether it was a genuine fossil," study lead researcher Andrea Cau, a paleontologist at the Geological Museum Giovanni Capellini in Bologna, Italy, said in the statement.

Real deal?

To ensure the specimen was real, and not a fake configured on the black market, the researchers analyzed it with synchrotron multi-resolution X-ray microtomography. This technique allowed the researchers to take multiple X-rays that were 100 billion times more powerful than X-rays used in hospitals. The scientists then assembled these X-rays to create a virtual 3D image of the dinosaur.

Much to the scientists' delight, the results showed that the specimen appeared to be a genuine animal, and not a fake specimen pieced together from different fossils, said study co-researcher Dennis Voeten, a researcher at the European Synchrotron Radiation Facility (ESRF).

The synchrotron also revealed that the dinosaur has a number of teeth in its mouth that can't be seen with the naked eye, study co-researcher Vincent Beyrand, a researcher at the ESRF, said. "We also identified a neurovascular mesh inside its snout that resembles those of modern crocodiles to a remarkable degree," Beyrand said in the statement. "These aspects suggest that Halszka was an aquatic predator."

The synchrotron also showed that Halszka walked on two legs while on land, likely with the same posture that modern ducks have. While in the water, the bird-like dinosaur likely used its "flippers" to swim, much like penguins do today, the researchers said. [In Images: Digging Up a Swimming Dinosaur Called Spinosaurus]

Despite its odd features, Halszka isn't the only bizarre dinosaur from the Gobi Desert. Several other strange Mongolian theropods appear to be closely related to it, which prompted the researchers to create Halszkaraptorinae, a new group that is a subfamily of the dromaeosaurs, a dinosaur group commonly known as raptors.

However, some scientists are still skeptical about Halszka's validity.

It could be a weird new type of dinosaur, "but because the specimen was collected by poachers and sold on the black market, I am just not 100 percent sure it hasn't been tampered with," said Steve Brusatte, a paleontologist at the University of Edinburgh. "Some fakes these days are so sophisticated."

The conclusion that the dinosaur was semiaquatic is not a "slam dunk," Brusatte added. "The evidence is mostly circumstantial at this point," he told Live Science in an email. "For instance, the long neck is seen in many other small theropods, and is even seen in modern dinosaurs that are not aquatic, like ostriches."

Despite this uncertainty, "I'm very excited about this fossil, but I think it raises more questions than it answers, and we'll probably be debating about it for years," Brusatte said.

The study was published online yesterday (Dec. 6) in the journal Nature.

Original article on Live Science.

The lawyer for Aaron Hernandez is suing the National Football League after an autopsy found that the 27-year-old player, who died by suicide after being convicted of murder, had a brain disease called chronic traumatic encephalopathy (CTE). A new study suggests that kids who play tackle football before age 12 are at risk of developing CTE, which can cause mood swings, aggression and dementia-like symptoms. And yet, another recent study found evidence of CTE in the brains of 99 percent of NFL players examined posthumously.

Is football inherently unsafe?

Despite this spate of bad news, there is no consensus on the answer to that question. Some researchers think football is best-avoided. Others think the sport can be made safer with equipment and training modifications, or at least that there's not enough evidence to throw out the entire game. [See Images of Brains with CTE]

"There are other things we would need to know in order to answer that," said Erik Swartz, a kinesiologist at the University of New Hampshire. But, Swartz said, researchers can't kick the can down the road for much longer.

"We don't want to continually say we need to learn more or we want to know more," he told Live Science. "We know a lot more today than we did 20 years ago. The science is better. The evidence is stronger."

Yellow flags

Chronic traumatic encephalopathy was once known as "punch-drunk syndrome" because it was thought to be a problem mostly exclusive to boxers. It's not. In 2002, an autopsy of former Pittsburgh Steelers football player Mike Webster, who died at 50, revealed the distinctive mark of CTE: a buildup of a protein called tau. Abnormalities in tau are also present in patients with Alzheimer's disease, and the symptoms of people with CTE are dementia-like. They include impulsivity, loss of memory, confusion, tremor and movement problems as well as depression and anxiety.

CTE can currently only be diagnosed by autopsy, though that may change. A study published in the journal PLOS ONE in September found that an inflammatory protein called CCL11 circulates at high levels in the cerebrospinal fluid of people with CTE compared with levels in people with Alzheimer's or without long-term brain damage. Researchers don't yet know if the protein increases early or late in the disease or whether the levels of the protein correspond to disease severity, but CCL11 could be a potential biomarker for diagnosing the disease during life, they wrote.

The inability of researchers to diagnose the disease until after a person dies is one of the problems facing scientists who are trying to figure out just how dangerous football really is. In July, Boston University-led research found evidence of CTE in the brains of 110 of 111 former NFL players that they examined. The limitation to this study is that because CTE can't be diagnosed until after death, families who noticed dementia-like symptoms in their loved ones were disproportionately likely to donate their brains to research. A diagnosis of CTE while the patient is alive would pave the way for more accurate statistics. 

Another problem is that many questions about how CTE develops and who is most vulnerable are still unanswered.

"Everyone has a different genetic background," said Jonathan Cherry, a postdoctoral fellow at Boston University and the lead author of the CCL11 research. "They have different environmental factors that can come into play."

What researchers do know, Cherry said, is that CTE doesn't require people to experience actual concussions, which are traumatic brain impacts that cause noticeable symptoms like confusion, nausea and ringing ears. Subconcussive impacts, if repeated enough times, can also lead to CTE. In the CCL11 study, Cherry and his colleagues found that the inflammatory protein, like CTE itself, correlated not with the number of concussions someone received in life, but with years of football played.

"Something we're trying to answer is how many hits is too many hits," Cherry told Live Science.

Making football safer

In the absence of sure information, there are attempts to make football safer. A major push, funded by the NFL, is to design better helmets. The newest to show up on professional fields is the Vicis Zero1, a helmet with a larger surface area and a flexible outer shell that gives during a collision "like a car bumper," Vicis CEO Dave Marver told Live Science in an email. Instead of traditional padding, the helmet's interior is made up of a series of flexible "columns," which can twist and buckle to absorb rotational forces. The helmet scored above all others in the NFL's 2017 laboratory testing. It's already being used in games by Kansas City Chiefs quarterback Alex Smith, according to Business Insider, and the University of Mississippi announced in March that it would be trying out the helmets for its players as well. Vicis plans to continue refining its technology, Marver said, and the company's engineers are using sophisticated computer modeling and new types of testing to continue to improve the helmets.  

Still, Vicis is careful not to market its product as concussion proof.

"As long as there are impact forces resulting from collisions, risk of concussion remains," Marver said. Different people have different thresholds for concussion, Marver said, and no helmet is foolproof enough to protect against all potential hits.

Helmet companies have overstepped on concussion-reduction claims before. Helmet company Riddell marketed its helmet as reducing the risk of concussion by 31 percent, even after a biomechanics lab warned the company in 2000 that no helmet could promise to reduce concussion risk. In 2013, Riddell was docked $11.5 million for making those claims as a result of a lawsuit filed by a Colorado family whose son suffered a severe concussion during a game.  

Some researchers argue that helmets are part of the problem — or at least not a clear-cut solution. The larger the helmet (and the VICIS Zero1 is larger than many), the more surface area there is for impact, the University of New Hampshire's Swartz said. (More impacts mean more brain trauma over time.) Helmets also offer a false sense of security to players, Swartz said. When your head is cocooned in inches of plastic and padding, you're more likely to ram it into other people than if you're helmetless. [5 Ways Science Could Make Football Safer]

Helmets undeniably provide head protection, Swartz said, and they're a necessary part of the game. But he and his colleagues are testing a method of helmet-free training for college and high-school players. The idea, Swartz said, is to teach players how to tackle and block without head protection so that their instinctive desire to protect their head becomes muscle memory.

"I played rugby for eight years, and it never occurred to me to lead with my head going into contact," Swartz said. Rugby players get concussions and head injuries, he said, but they don't endure as many head impacts as football players do.

In a study in which University of New Hampshire football players were randomly assigned to receive the helmetless training or not, Swartz and his team found that those who'd trained without helmets experienced 30 percent fewer head impacts over the course of a season than those who trained with helmets. The researchers have done a larger randomized trial in high-school students, but those results have yet to be published.

Whether 30 percent is enough to prevent long-term damage, no one knows.    

"We won't be satisfied with a certain threshold," Swartz said. "We just want to get it as low as we can."

Treatment and timing

Head impacts could be even more damaging for athletes who are still recovering from a prior concussion. That's why concussion diagnosis is so important. Even so, diagnosis among athletes hasn't been as throrough as it needs to be, experts said. [5 Facts About Chronic Traumatic Encephalopathy (CTE)]

When an athlete gets hit on the head in the field, National Collegiate Athletic Association (NCAA) standards call for a battery of cognitive and neurological tests that assess things like symptoms and balance on the spot. That's not enough, said Semyon Slobounov, a professor of kinesiology and neurosurgery at Penn State University and author of  "Concussions in Athletics: From Brain to Behavior" (Springer-Verlag New York, 2014). To really assess concussion damage, Slobounov told Live Science, athletes need a direct assessment. At Penn State's Center for Sport Concussion Research and Service, that assessment can include functional magnetic resonance imaging (fMRI), diffusion tensor imaging, electroencephalograms and other methods of directly measuring brain function. 

"Concussive injury is definitely linked to pathophysiological alteration of the brain," which means meaning changes to the structure and function of brain tissue, Slobounov said.

That alteration can persist, even once-obvious symptoms like confusion or dizziness clear up, he said. In other words, letting athletes back on the field when symptoms abate doesn't guarantee that their brains have really recovered. Most players are cleared to play after a week, Slobounov said, while studies on blood flow show that alterations in brain function persist past 30 days. The damage may be compounded in players who take more hits before the brain heals.

At the same time, Slobounov said, athletes' brains recover from concussions faster than the brains of nonathletes, and he and his colleagues have found that light, low-impact exercise started as early as two days post-injury can speed recovery. The benefit of exercise for the brain is one reason Slobounov is among the experts who are reluctant to throw the football out with the bathwater.

"We should be concerned about disability and mobility and obesity issues and kids not getting exercise," Slobounov said, while still characterizing the questions surrounding concussions as "a serious problem."

The benefits of a physically active lifestyle make Swartz hesitate to condemn football, as well. There may eventually be enough evidence to suggest that the full-tackle game be delayed to older ages, he said. In September, Boston University researchers published data in the journal Translational Psychiatry that showed that individuals who began playing before age 12 were more likely to show depression, problems with cognitive functioning and trouble with behavioral regulation in middle age than those who had started later, as assessed over the phone and in online psychological testing. More research is needed to make any policy changes or guidelines, those researchers wrote.

"If a parent were to decide, 'My child is going to play football, but they're going to start off for two or three years in flag football, then progressively move over to a tackle football,' that is almost objectively a safer approach," Swartz said, simply because the child will receive fewer total head impacts. The age at which children have the capacity to weigh the risks and rewards of the game is also worth thinking about, he said.

For Cherry, who disentangles the postmortem consequences of CTE, it's hard to see how to reduce the risk enough.

"When people ask what is the best way to not get CTE, I tell them that you don't get hit in the head," he said. "That is the surefire way to not get CTE. It gets very difficult to say, How can you make the sport safer? when the way is to not get hit in the head — and that's football. So I have a lot of trouble when people ask that question."

Original article on Live Science. 

There's nothing quite like the rush of seeing your favorite sports team pull off a win at the last second. But watching live sports can put some serious stress on your heart, a new, small study finds.

Watching a hockey game live can more than double a fan's heart rate, according to the study. And you don't even have to be in the arena for your heart rate to climb: Catching the game on TV can also have an effect, according to the study, published today (Oct. 5) in the Canadian Journal of Cardiology.

The excitement of sports is likely responsible for the observed increases in heart rate, said study author Dr. Paul Khairy, a cardiologist at the Montreal Heart Institute. [Heart of the Matter: 7 Things to Know About Your Ticker]

But the new study is the first to demonstrate that the ambience of a live game — being surrounded by cheering fans, being closer to the action and experiencing an increased level of engagement — may all contribute to the heightened emotional stress response in fans, Khairy told Live Science.

In the study, the heart rates of fans who watched a hockey game in person increased by 110 percent, on average, from their resting heart rates. That's comparable to the increase you'd see in someone running, jumping rope or doing any other vigorous form of exercise, Khairy said.

Fans who watched the same game on TV had a 75 percent increase in their heart rates, on average, which is similar to the heart rates seen with moderate physical activity, such as a casual bike ride, Khairy noted. 

This is the first time that the heart-rate response of hockey spectators has been measured, the researchers wrote. But previous studies from Europe have found higher heart rates in soccer fans who watched World Cup matches in person. These increases occurred after their team scored a goal or after their team beat an opponent.

In the new study, the researchers looked only at fans of the Montreal Canadiens, a team with an avid fan base in a country where hockey is considered the national winter sport. The study was the brainchild of two 13-year-old girls in Canada, one of whom was Khairy's daughter.   

They recruited 20 participants ages 23 to 63. Half of the participants attended Canadiens games while the rest watched the action at home. Both groups wore heart-rate monitors during the games.  

Because the researchers included fans of only one team, the results may not apply to all hockey fans, the study noted.

Taking hockey to heart

The study found that fans' heart rates peaked most often during overtime periods. The second-most-stressful time for fans was during scoring opportunities by the Canadiens, followed by the opposing team's attempts to put the puck in the net. 

Surprisingly, a person's interest in the sport and engagement as a fan were not linked to changes in heart rate during the game, Khairy said. However, he added that he suspects there might have been a different result if researchers had developed their own way to measure passion in hockey fans rather than adapting a tool originally designed for soccer spectators.

Although fans watching any sport can experience a similar amount of excitement as was observed in this group of hockey enthusiasts, these results may not apply to other sports, Khairy said. There are too many elements that differ among sports — such as the pace of the game, a fan's emotional attachment to a team, and even the number of high-intensity moments — that prevent researchers from making similar generalizations, he said.

A fan's emotional reaction to a game can be intense, Khairy said, and that could trigger cardiovascular problems.

Fans who experience cardiac symptoms during a game should seek immediate medical attention rather than waiting for a convenient moment, such as in-between periods, Khairy said. Many arenas and ice rinks have cardiac defibrillators on hand, as well as people trained in using them, he added.

Originally published on Live Science.

Former NFL player Aaron Hernandez had one of the most severe cases of chronic traumatic encephalopathy (CTE) ever seen in someone his age, according to his lawyer. But how did his condition progress so quickly?

Hernandez was just 27 when he died from suicide earlier this year. A recent analysis of his brain by researchers at Boston University's CTE Center showed that Hernandez had "stage 3 out of 4" CTE, with stage 4 being the most severe. This is particularly extreme for someone his age — his brain showed the type of damage that is typically seen in pro-football players in their 60s, according to The New York Times.

CTE is a degenerative brain disease found in people with a history of repeated blows to the head, including pro-football players and boxers, according to the CTE Center. It is thought that these repeated hits cause damage to brain tissue, leading to a buildup of an abnormal protein called tau. Currently, the condition can be diagnosed only by examining a person's brain tissue after death. [10 Things You Didn't Know About the Brain]

The characteristic brain changes of CTE can begin months, years or decades after the last head injury or the end of a person's athletic career, the CTE Center said.

However, many questions about CTE remain, including exactly which factors affect a person's risk of developing CTE or how the disease will progress. Many factors could be involved, but much more research is needed to identify these factors and examine their role in the condition, according to experts. For example, although researchers hypothesize that frequent head trauma plays a role in the disease, it's not clear exactly how many hits to the head a person needs to experience, or how severe the hits need to be, to trigger the brain changes seen in CTE, according to the CTE Center.

Kevin Bieniek, a research fellow in neuropathology at the Mayo Clinic College of Medicine in Jacksonville, Florida, said that there may be both genetic and environmental factors that play a role in the risk of developing CTE, and in the disease's progression. Some of these factors might be protective, while others could contribute to a person's risk, he noted.

For example, it's thought that a gene called APOE may influence CTE risk. Some studies have found that a version of this gene, called APOE e4, is more common in people with CTE, compared with people without the disease, suggesting it may be a risk factor for developing the disease, according to a 2011 paper published in the journal Clinics in Sports Medicine. About 57 percent of people with confirmed CTE have at least one copy of the APOE e4 gene variant in their genome (out of the two copies that are inherited from each parent), according to the paper. However, only about 28 percent of people in the general population have at least one copy of the APOE e4 gene, the paper noted.

The evidence linking CTE with APOE e4, however, is still not conclusive, Bieniek told Live Science, so more studies are needed to confirm that it is a real risk factor.

In addition, a slew of environmental factors could potentially play a role in the disease, such as the number of head injuries a person experiences, the severity of these injuries, and the age at which a person experiences the head injuries, Bieniek said. In addition, a person's use of substances such as alcohol and tobacco might also play a role in the likelihood of developing CTE, he said.

The type of sport a person plays, or even their position (such as a football wide receiver versus a lineman), might also affect a person's risk of CTE, according to the Clinics in Sports Medicine paper.

To better understand how these environmental factors affect a person's risk of CTE, researchers will need to study many cases of CTE and compare them with athletes who don't have CTE, as well as to nonathletes without CTE, Bieniek said. Researchers would also need a lot of information about each of these cases, including their experience with head injuries, and whether they had any psychiatric or neurological conditions.

Ideally, researchers would start studying athletes and nonathletes at a young age, Bieniek said. They would collect information on numerous factors, such as the type of sports and activities they participate in; the number of games they play; the number of concussions or injuries they experience, and how severe these injuries are; and whether they develop symptoms such as memory loss or depression, Bieniek said. Then, after the participants' death, researchers would study the brains for CTE and look for relationships between the studied environmental factors and the risk of CTE.

This "ideal" study would be technically challenging and take a tremendous effort. Currently, "we are trying to answer elements of these questions on select [groups] and populations, and the cumulative findings of these studies will help paint a better picture" of CTE's risk factors, Bieniek said.

 Original article on Live Science.

Former NFL player Aaron Hernandez had a severe form of the brain disease chronic traumatic encephalopathy (CTE) when he died earlier this year, a new analysis of his brain shows.

Researchers at Boston University's CTE Center, who studied Hernandez's brain, said on Thursday (Sept. 21), that the former New England Patriots player had "Stage 3 out of 4" CTE, with stage 4 being the most severe. The damage seen in Hernandez's brain was particularly severe for someone his age — at 27, Hernandez showed the type of damage that is typically seen in pro-football players in their 60s, according to the New York Times.

It was "the most severe case they had ever seen in someone of Aaron's age," Jose Baez, a lawyer for the Hernandez family, said at a press conference announcing the findings.

Hernandez committed suicide on April 19, while serving a life sentence in prison for murder.

CTE is a degenerative brain disease found in people with a history of repeated blows to the head, including pro-football players and boxers, according to the CTE Center. It is thought that repeated hits to the head cause damage to brain tissue, leading to a buildup of an abnormal protein called tau. The characteristic brain changes of CTE can begin months, years or decades after the last head injury or the end of a person's athletic career, the CTE Center said. So far, the center has identified CTE in more than 100 former NFL football players.

The condition can cause symptoms such as memory loss, impaired judgment, impulse-control problems, aggression, depression, anxiety and suicidality, the CTE center said. Several other former NFL players who committed suicide, including Adrian Robinson, Dave Duerson and Junior Seau, were later found to have CTE.

Currently, the condition can be diagnosed only after death.

Hernandez's family is suing the NFL and the Patriots on behalf of his 4-year-old daughter, Avielle, seeking unspecified damages for the loss of her father, according to Reuters.

Original article on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

For many, American football is a beautiful game that is simple to enjoy but complex to master. Choreographed with a mixture of artistry and brutality, it features the occasional "big hit" or bone-jarring tackle, forcing a fumble and turning the tide of the game.

But with this part of football comes justified concern about the long-term health effects of engaging in this type of activity over time, concerns that abound in practically every high-impact contact sport. It is possible that effects of continued involvement may accumulate quietly in the background until they show themselves, later in life.

A recent study appeared to give a "big hit" to the game of football itself, with findings that nearly all the brains of 111 deceased NFL players studied showed signs of chronic traumatic encephalopathy, or CTE.

At the University of Florida, our interdisciplinary team has studied brain injuries in athletes, military veterans and civilians for many years. Regarding sports concussion, there are many gaps in our knowledge and many associated issues to consider as we develop ways to keep our athletes, both young and old, safe.

The concussion 'explosion'

Concussions result from mechanical impact to the brain that produces transient changes in awareness or consciousness and a range of other symptoms. A 2016 study reported that between 1.1 million and 1.9 million concussions occur each year in children.

Although diagnosed concussions have been the primary focus, they are not the only, or maybe even the main, problem. There is also rising concern about subconcussive impacts, repetitive blows that may not be severe enough to cause clinical symptoms. There may be hundreds of subconcussive impacts per player, per year.

In response to widespread concern, organized sports organizations from Pop Warner to the NCAA to professional levels have developed and implemented concussion management protocols to help in the identification and management of concussions.

Yet the massive attention given to concussion management and prevention has produced a level of public pseudo-awareness about CTE that currently outstrips what is scientifically known about the disorder.

Missing links and gaps in knowledge

Several scientific studies have linked repetitive brain trauma to CTE.

CTE is a "tauopathy" in which the normally occurring protein tau becomes misfolded and accumulates at the depths of the folds (sulci) of the brain, in regions that may also be susceptible to mechanical forces during head impacts. The abnormal accumulation of the tau protein gives rise to a cascade of brain pathology that leads to cognitive impairment, neuropsychiatric problems (depression, anxiety, aggression, reduced impulse control), functional decline and, eventually, death.

The study published July 25 that showed CTE in 110 of 111 deceased, former NFL players reflected a startling 99 percent prevalence rate.

The results were reported by news outlets across the world, leading many people to think that CTE is an all but inevitable outcome of playing football or other sports.

But is it? And most importantly for parents, coaches and fans, what is the actual risk to my kids, my players and my team?

The answers to these questions are not yet known, though the risk to the individual player is very likely to be considerably less than would be suggested by available research findings.

Two important facts should be considered.

First, studies of CTE have all been conducted on small samples of brains delivered to CTE research centers by families of former players who have had concern about post-retirement cognitive, psychiatric or behavioral problems and symptoms.

The likelihood of finding brain pathology in these brains of symptomatic players is high, but these results cannot be generalized to all former football players, many of whom are living healthy lives in retirement.

Second, no study has evaluated even a single living player to determine whether he or she exhibits the cognitive, psychiatric or behavioral signs of CTE and then followed that person to autopsy to verify that CTE-associated pathology actually exists in their brains.

So, we do not know the actual prevalence of CTE in the general population of players, though it is assuredly much lower than those quoted by studies of symptomatic players.

Why do some get CTE and others do not?

We also don't know much about who develops CTE and who doesn't. There are over 10,000 living NFL retirees, yet the entire science of CTE is based on samples of less than a few hundred former NFL players and a handful of athletes from other sports. This means that some of those exposed to the risk of repetitive head impacts develop CTE, but most do not.

There are several factors that may contribute to the development of brain dysfunction and disease, including:

• medical or genetic risk factors
• medical and psychiatric problems such as depression, anxiety, sleep disorders and abuse of prescription medications or other drugs and substances
• reduced educational attainment or literacy, or socioeconomic deprivation

In addition, some athletes have poor adjustments to retirement, leading to psycho-social and psychiatric maladjustment, marital or financial difficulties, substance abuse and other behavioral problems.

Repetitive head impacts may heighten risk of CTE, but other factors are undoubtedly involved in determining whether risk becomes reality. Reducing risk of CTE will involve targeting and treating these other factors as well.

What parents, coaches and athletes need to know

We need to take seriously the possible health consequences of prolonged exposure to repetitive head impacts and concussions.

That said, parental decisions to remove children from contact sports should be weighed against the many proven positive aspects of participation in team sports. Decisions should not be based on inflated risk assessment. Several studies have shown that recreational or scholastic athletic participation in youth conveys no significant added risk to brain health later in life.

Still, the developing brain may be more susceptible to injury and may take longer to recover. Knowledge of the individual player and his or her response to injury should guide parents, coaches and athletes in decision-making. Some youth are more injury-prone than others, and some have other conditions (e.g., ADHD, learning disability) that may affect how they react to head impact. When all factors are considered, the strongest predictor of recovery is the severity of initial symptoms.

All states now have legislation requiring public schools to have a concussion program in place. Parents should ask their school or athletic organization what their policies are regarding concussion management.

While helmet manufacturers are developing helmets that might provide greater protection, there is not enough evidence to recommend one over another. We do know, however, that appropriate fitting of helmets and protective gear is necessary to get the full protective benefit.

Some measures to reduce possible exposure and risk have been implemented. The Dartmouth University football program has significantly reduced contact practices for its football team. Other Ivy League teams and organizations have followed suit. The NCAA has recently recommended the elimination of two-a-day practices and restricted the number of contact practices allowed in football.

Physicians and athletic trainers at the University of Florida are using data from helmet sensors originally designed to help detect concussions to inform coaching staff on which specific practice drills and pad configurations may incur higher risk so that such drills can be adjusted.

Ongoing research for this important issue is focused on developing techniques for accurate diagnosis while an individual is alive and understanding the exact pathophysiology that might inform future disease-modifying treatment, in addition to our current treatments aimed at reduction of symptoms.

For those athletes who choose to continue the sports they love, we hope for continued innovations and policies that make their participation as safe as possible.

Russell M. Bauer, Professor, Clinical & Health Psychology and Neurology, University of Florida and Michael S. Jaffee, Vice chair, Department of Neurology, University of Florida

This article was originally published on The Conversation. Read the original article.

A study of the brains of more than 200 deceased football players — including 111 who played in the National Football League (NFL) — reveals that nearly 90 percent of the players had a brain disease called chronic traumatic encephalopathy (CTE).

CTE is likely caused by repeated blows to the head, according to the Mayo Clinic. People with the condition get worse over time and can develop symptoms such as learning difficulties, memory loss and depression.

But CTE can be definitively diagnosed only after a person has died, during an examination of the person's brain, according to researchers at Boston University's CTE Center, who conducted the new study. [Images: Brains with CTE]

In the study, published today (July 25) in the journal JAMA, researchers found evidence of CTE in 177 out of 202 brains, or 87 percent of the individuals. Among the brains of NFL players, 110 out of 111, or 99 percent, had CTE. (The other men who had donated their brains for the study played football either semiprofessionally, or in college or high school.)

CTE ranges in severity from mild to severe. Among the former NFL players in the study, the disease was "frequently severe," the researchers found, with 71 percent of these players having severe CTE.

To learn about the symptoms the players may have had before they died, the researchers interviewed people close to the players, such as spouses or adult children. These interviews were completed for 111 of the donors in the study.

The researchers found that 96 percent of the men with severe CTE and 89 percent of those with mild CTE had shown changes in their behavior or mood, including impulsivity, depression, apathy and anxiety. In addition, they found that 95 percent of the men with severe CTE and 85 percent of those with mild cases of the condition had shown changes in their thinking abilities, such as problems with memory, attention and language.

Interviews with people close to the men also revealed that nearly all of the players' cases of CTE were progressive, meaning that their conditions got worse over time, the study said. However, the researchers noted that they could not confirm that the disease was progressive based only on examining the players' brains, as this provided only a snapshot in time of the disease.

The donor brains in the study came from players who played a wide range of positions on the field, including lineman, quarterback and kicker. (Different positions come with different likelihoods of being tackled.) Donors had played football for 15 years, on average.

Overall, the findings suggest that CTE "may be related to prior participation in football," the researchers wrote in the study.

The researchers noted that the study had limitations. For example, the researchers said, donors in the study and their families may have made the decision to donate because they were aware of CTE and thought the players may have had symptoms of the disease.

Originally published on Live Science.

Some emergency-medicine doctors want to banish the phrase "dry drowning" because the term doesn't actually refer to any medically accepted conditions.

"Dry drowning" tends to come up in the summer, as it did this June, after a young boy in Texas died several days after swimming and his parents were told it was because of dry drowning.

But terms such as "dry drowning," "delayed drowning" and "secondary drowning" are all incorrect, and can cause unnecessary alarm, according to the American College of Emergency Physicians (ACEP). [10 Ways the Beach Can Kill You]

"There are no cases of completely normal, asymptomatic patients who suddenly die because they went swimming a few days ago," Dr. Rebecca Parker, president of the ACEP, said in a statement yesterday (July 11). "It's time to retire those incorrect terms, because it is inaccurate and incorrect to say a child was initially fine after a water event and then 'dry drowned' a day or a week later."

Parker said media reports of such instances "unduly alarm" parents.

Still, in very rare instances, a person can die as a result of breathing problems several days after being submerged in water. The name for such an occurrence? Drowning.

The definition of drowning is when a person has any type of breathing problems after being submerged in a liquid, said Dr. Howard Mell, an emergency-medicine physician and a spokesperson for ACEP. For example, if a person goes underwater and comes up sputtering a bit, that's technically drowning, Mell said.

When most people think of drowning, they imagine a person going underwater and never coming up again because he or she dies from a lack of oxygen, Mell told Live Science. But "that would be the far end of the spectrum," he said. The medical term "drowning" includes a wide range of scenarios, including deadly problems, but also milder ones.

Drowning doesn't mean dying, he added.

In the mildest cases, drowning is when water "goes down the wrong pipe," but this phrase is also inaccurate, Mell noted. What's really happening is that water gets to the back of the throat and comes into contact with the epiglottis, which is the flap of cartilage in the back of the throat that blocks the breathing tube when you swallow. The muscles around the epiglottis then spasm to protect you from inhaling water. A person may cough and clear out the water, and then have no further problems.

"If you are symptom-free, it's no longer drowning," Mell said. "It's not going to come back."

The bigger concern is when a person is coughing when he or she comes out of the water and doesn't stop coughing, Mell said. This could indicate that a person did inhale water — in other words, that water got past the protective barrier of the epiglottis, and into the lungs. [10 Bizarre Diseases You Can Get Outdoors]

When even a drop or two of water gets into a person's lungs, it can cause problems, Mell said. This is because the water can wash away a compound called "surfactant" that coats the inside of a person's lungs. Surfactant is a slippery substance that helps keep the air sacs within the lungs open so that oxygen and carbon dioxide can be exchanged between the air sacs and nearby blood vessels. If the surfactant washes away, the immune system may react, leading to a deadly condition called acute respiratory distress syndrome.

If a person inhaled water, and some of the surfactant was washed away, the signs of this would be clear, Mell said. A person would come out of the water coughing, or start coughing within a couple of minutes, he said. An hour later, the cough would be horrid, and an hour after that, the person would be losing their normal color, and turning gray.

The term "dry drowning" came about because there were cases in which people died from this process, but they died several days after they inhaled water, Mell said. "It was harder for people to comprehend" the concept that people can die of drowning when they're not in water, even if they had been coughing and sputtering since they were in the water, he said.

"It's not a benign, mysterious process; it's an obvious process" that starts right away, not several hours or days after a person gets out of the water, Mell said.

There's no process that would be considered "drowning" that would start only several hours after a person was out of the water, Mell added. So if a child develops a cough a few days after swimming, that's just a cough.

But if the person is coughing when he or she comes out of the water, and that coughing continues and gets worse, the person definitely should be taken to the emergency room, Mell said.   

In addition to the ACEP, these organizations also discourage the use of terms such as "dry drowning" and "secondary drowning": The World Health Organization, the International Liaison Committee on Resuscitation, the Wilderness Medical Society, the International Lifesaving Federation, the International Conference on Drowning, the American Heart Association, the American Red Cross and the Centers for Disease Control and Prevention. 

Originally published on Live Science.

A 4-year-old boy in Texas died recently, nearly a week after he went swimming, from what his parents were told was "dry drowning." But what exactly does this mean?

The boy, Frankie Delgado, was playing in the waters of the Galveston Bay when he was knocked down by a wave, according to CNN. Initially, the boy seemed all right. But the next day, he began vomiting and having diarrhea. Nearly a week later, the boy said he had shoulder pain, and later, during a nap, he stopped breathing. Although he was rushed to the hospital, doctors were unable to resuscitate him, CNN reported. [5 Tips for Safe Summer Swimming]

Doctors said they found fluid in Frankie's lungs and around his heart, and they told his parents that he died of "dry drowning," according to CBS affiliate KHOU-TV. However, the official cause of his death has not been released by the county coroner.

Dry drowning occurs when, after being submerged in water, a person's vocal cords experience a spasm and close, making it difficult to breathe, said Dr. Mike Patrick, an emergency-medicine physician at Nationwide Children's Hospital in Columbus, Ohio, who was not involved in the boy's care. When this happens, the body's response is to send fluid to the lungs to try to open up the vocal cords. But this can lead to excess fluid in the lungs — a condition called pulmonary edema. Symptoms of dry drowning usually start within an hour after a person is submerged in water, Patrick said.

Another uncommon way people can drown some time after being submerged in water is called "secondary drowning." In this case, water dilutes or washes out the lungs' surfactant, a slippery substance that's needed to prevent lung sacs from sticking together and collapsing, Patrick told Live Science. Without the surfactant, the lung sacs start to stick together, and the body can't properly exchange carbon dioxide and oxygen, Patrick said. This causes the same shock response as dry drowning — the body sending fluid to the lungs — resulting in pulmonary edema. Symptoms of secondary drowning usually start within 24 hours after a person is submerged in water, he said.

Both dry drowning and secondary drowning are rare, Patrick said, affecting only about 5 percent of kids who have a "near-drowning" experience, in which they are submerged in water and have trouble breathing but are revived.

Doctors recommend that, if a child is submerged in water, parents should keep a close eye on the child for 24 hours following the submersion. If the child experiences respiratory symptoms such as difficulty breathing, wheezing, coughing or chest discomfort, they should get the child medical attention right away, said Patrick, who also hosts the parent-advice podcast PediaCast.

Delgado's family has set up a GoFundMe account to help with expenses for his funeral. "There are no words to describe how heartbroken we are over the passing of Baby Frankie," the page says. "He was loved by so many people … the world lost a beautiful soul."

Original article on Live Science.

Running is a sport that both men and women enjoy, whether they're racing in a 5K or a marathon, or competing for a team or their country while speeding around a track. But no matter the venue, it's pretty common to see men clock faster times than women do.

Given that both men and women train equally hard, why is it that men, on average, are faster runners than women? Even the world's fastest man is about a second speedier on the 100-meter dash than the world's fastest woman: Usain Bolt did it in 9.58 seconds, versus the late Florence Griffith Joyner's time of 10.49 seconds.

The answer to this gender bender is multifold, but it has a lot to do with hormones and body size, doctors told Live Science. [Who Are the World's Fastest Man and Woman?]

Before girls and boys hit puberty, their bodies are fairly similar. During puberty, however, boys experience a surge of testosterone. By adulthood, some men have up to 20 times more testosterone than women do, according to HealthLine.

Testosterone plays several roles, including telling the body to create new blood cells, keeping bones and muscles strong and prompting growth spurts, according to the Society of Endocrinology.

"Because [women] produce less testosterone, we are at a disadvantage in terms of muscle," said Dr. Emily Kraus, a primary care sports medicine physician at Stanford Health Care in California. "Males have a greater amount of muscle bulk."

A man's leg is about 80 percent muscle, compared with about 60 percent muscle in a woman's leg, Kraus said. That extra muscle can help men run faster, she said. Also, men's muscles tend to have larger fast-twitch muscle fibers, which help with sprinting, than women do, Kraus said.

In addition, women have more estrogen than men do, which leads them to have a higher percentage of body fat than men have. "That can also lead to a small disadvantage for running performance [for women, in comparison with men]," Kraus said.

Body size is another factor. Women, on average, have smaller lungs than men do, meaning their maximal oxygen consumption (VO2 max) is lower. The VO2 max for a sedentary woman is about 33 milliliters of oxygen per kilogram of body mass per minute, while a young sedentary man's is about 42 ml/kg/min, according to a 1998 study in the journal Medicine and Science in Sports and Exercise.

In elite runners, VO2 max is higher, but men still top women. Basically, "the amount of oxygen produced at maximum exertion is greater in males than in females," Kraus said. This means that women have to work harder to breathe in oxygen that they can deliver to their muscles, she said.

Women's hearts also tend to be smaller than men's, which means they have a smaller stroke volume, or the amount of oxygenated blood that the left ventricle pumps out in one beat.

"Even though [women] have a higher heart rate, it's not enough to counterbalance the lower stroke volume that [women] have," Kraus said. "Each time the heart pumps blood, that amount of blood is less in a female than in a male." That means less blood and less oxygen are delivered to women's muscles, she added.

To top that off, women also have less hemoglobin, the protein in red blood cells that carries oxygen to the body's tissues, including the muscles, Kraus said.

Biomechanics and running

As far as biomechanics, men usually have longer legs than women do, meaning they have more room for muscle, as well as a longer stride length, said Dr. Miho Tanaka, an assistant professor of orthopedic surgery and director of the Women's Sports Medicine Program at Johns Hopkins Medicine.

Moreover, because women tend to have wider hips, their running stance is not as efficient as a man's is, Tanaka said. 

"Muscles work efficiently when everything is in line," Tanaka said. "If your hips are very narrow, like a man's, then your quads are running straight from your hips, past your knees. It's in a straight line, so it's acting in the same direction that you're running."

For a runner with wider hips, however, the "muscles almost have to turn a corner, so to speak," Tanaka said. "It's not like the optimized function for the muscle."

This isn't to say that women with wide hips can't run, but it's one of the many factors that explain why women, on average, aren't as fast as men, she said.

To sum it up, women's lungs and hearts have a smaller capacity to breathe in oxygen and pump oxygenated blood, respectively, and they have less hemoglobin in their blood to carry that oxygen. Moreover, women tend to have less lean muscle and shorter legs than men do, as well as wider hips, which makes running less efficient.

"It's quite impressive; even with these disadvantages at baseline, some women are still quite competitive with men," Kraus said.

Original article on Live Science.

Live Science is bringing our readers a monthly series on personal health goals, with tips and tricks we've gathered from the many health experts we've interviewed. Each month, we'll focus on a different goal, and the goal for June is Get Outdoors to Stay in Shape. Follow us on Facebook and Twitter to connect with other readers who are working toward these goals.

Jump to: January — Lose Weight | February — Eat Healthy | March — Start Exercising | April — Cope with Allergies | May — Protect Yourself from Sun and Heat

For getting fit and staying in shape, experts say there's no single type of exercise that's considered "the best." The most important thing is that you like the activity you choose to do.

Here on this page, we've pulled together important information on some of the most common outdoor activities, as well as tips on how to stay motivated and avoid health risks while you exercise outdoors this summer.

Walking

One of the simplest ways to get fit outdoors is to take a walk; research shows that brisk walking on a regular basis can improve the health of your heart, lungs and circulatory system; reduce your risk of cardiovascular disease and type 2 diabetes; and help you maintain a healthy weight. Walking is also a low-impact exercise, so it's easy on the joints and muscles. According to the Centers for Disease Control and Prevention (CDC), just 10 minutes of brisk walking, three times a day for five days a week (for a total of 150 minutes per week) is enough to improve your aerobic health.

Read more about the benefits of walking and how much you really need:

• How Short Bursts of Activity Can Get You Fit
• Just 20 Minutes of Walking May Reduce Inflammation in Your Body
• The Truth About '10,000 Steps' a Day
• Aerobic Exercise: Everything You Need to Know

Running

Like walking, running helps improve your cardiovascular fitness. If you chose to run rather than walk, you don't need to exercise for quite as long. According to the most recent physical activity guidelines from the U.S. Department of Health and Human Services (HHS), adults can do 75 minutes of vigorous-intensity activity, such as running, to get the same benefits as 150 minutes of moderate-intensity activity.

Here is more useful information for runners:

• Even a 5-Minute Run Is Great for Heart Health
• Just How Short Can Your Workout Be?
• Here's How You Can Prevent Foot Blisters While Running
• Skip Your Run Today? Science Says You Can (Partly) Blame Your Friends
• Walking and Running May Offer Similar Heath Benefits

Swimming

Swimming is another good way to improve your aerobic fitness, and it offers health benefits similar to those of walking and running. What's more, because swimming is easy on your muscles and joints, you may be able to exercise for longer in the water than you could on land without increased muscle or joint pain, according to the CDC. Swimming may be particularly good for older adults, as it may help strengthen core muscles and reduce the risk of falls, one study found. In addition, swimming may help people with arthritis increase the use of their joints without worsening their symptoms, the CDC says.

Here are some important things to know about swimming:

• Why Swimming May Be the Best Exercise for Older Adults
• Good Sports: Longer Lives Linked to Swimming, Racquetball
• Do I Really Have to Wait an Hour After Eating Before Swimming?
• How Top Swimmers Can Go Faster: It's All in the Fingers

Hiking

Hiking not only gives you an aerobic workout, but it may also be good for your mental health; a number of studies suggest that spending time in nature reduces stress levels and negative thinking. What's more, if you don't have time to work out during the week, a long hike or two on the weekend may offer health benefits similar to those seen in people who exercise more frequently, according to a recent study.

Here are some important things to know about hiking and experiencing nature:

• 5 Minutes with Nature Can Boost Mental Health
• Got Nature? Why You Need to Get Out
• Walking in Nature May Reduce Negativity
• 'Weekend Warrior' Workouts Improve Health
• Hiking with Kids: 7 Tips for Getting Outside This Summer

Cycling

Cycling is another low-impact exercise that provides health benefits but is easy on your muscles and joints. And studies suggest that even a little biking can help people avoid weight gain. Although men may have concerns about how cycling could affect their fertility or sexual function, a recent study found no link between cycling and infertility or erectile dysfunction. Biking may even be good for your mental health, with some studies finding that cycling to work is linked with better well-being than driving to work.

Here are some important things to know about cycling:

• Biking and Brisk Walking Can Keep Pounds Off
• Walking or Biking to Work May Make You Happier
• Can Cycling Crimp Sex for Men?

Getting motivated

It may be difficult to keep up a regular exercise routine, but here are some tips to help you overcome some of the most common barriers to exercise:

• How to Start an Exercise Routine and Stick to It
• 4 Easy Ways to Get More Exercise
• Move It! How to Exercise When You're Depressed
• Inactivity Can Become a Habit: 4 Tips to Get You Off the Couch
• How Emotions Can Sabotage Exercise

Outdoor dangers

Getting outdoors can be a great way to get fit this summer, but there are a number of risks you might encounter during your outdoor adventures, from tick bites to sunburn. Here are some tips on how to stay safe while you enjoy summer fun outside:

• 10 Important Ways to Avoid Summer Tick Bites
• 10 Bizarre Diseases You Can Get Outdoors
• 13 Tips for Staying Hydrated in the Summer Heat
• 5 Tips for Safe Summer Swimming
• How to Choose a Sunscreen That Protects You
• 10 Health Woes Summer Can Bring
• No-Brainer: Bike Helmets Protect Noggins and Face Bones

Editor's note: On Wednesday April 20, Serena Williams confirmed she is pregnant.

Tennis star Serena Williams hinted today that she may be pregnant, but is it safe for her to continue serving up hard hits on the court while she's expecting?

Earlier today (April 19), Williams, who is 35 and recently got engaged, posted a picture of herself to Snapchat with the caption "20 weeks," according to Sports Illustrated. However, Williams later deleted the post. If Williams' pregnancy began 20 weeks ago, this would mean that she was pregnant when she won the Australian Open in January.

Experts say that, in general, playing tennis is safe for pregnant women, at least in early pregnancy, although it could be risky in later pregnancy.

"Tennis is still a good sport for the average woman who's pregnant because it is a moderate cardiovascular form of activity," said Dr. Jonathan Schaffir, an obstetrician/gynecologist at The Ohio State University Wexner Medical Center, who is not involved in Williams' care. However, pregnant women should play at the level they are accustomed to playing, Schaffir said. This means that, because Williams is conditioned to play at a high level, she could continue to play at that level in early pregnancy, Schaffir said. But for the average woman, it wouldn't be advisable to play for as long or as intensity as Williams does, he noted.

Williams is "an elite athlete who is probably in peak physical form," Schaffir said. "The kind of tennis that [she] plays is a much higher intensity and duration" than what the average woman plays, he said. [11 Big Fat Pregnancy Myths]

Pregnant women should speak with their health care provider before starting any exercise regimen during pregnancy, Schaffir said.

In general, if a woman is otherwise healthy and isn't at high risk for certain complications during pregnancy, she can safely engage in most types of exercise, according to the American Congress of Obstetricians and Gynecologists (ACOG). In fact, regular exercise during pregnancy has a number of health benefits, including reducing back pain, decreasing the risk of gestational diabetes, strengthening the heart and blood vessels, and promoting healthy weight during pregnancy, ACOG said.

However, pregnant women are generally advised to avoid sports that put them at increased risk for falls, including downhill skiing, water skiing, surfing, off-road cycling, gymnastics and horseback riding, according to ACOG. Women are also advised to avoid sports that could put them at risk of getting hit in the belly, such as ice hockey, boxing, soccer and basketball.

Schaffir said he doesn't consider tennis to be a sport to avoid in early pregnancy, because there is a low risk of an impact to the body. However, later in pregnancy, a woman experiences changes to her body that could make playing tennis harder and more risky, and therefore not advisable, Schaffir said. [Blossoming Body: 8 Odd Changes That Happen During Pregnancy]

For example, pregnant women experience a shift in their center of gravity as their belly gets larger, which makes them more likely to lose their balance or fall, ACOG said. In addition, hormonal changes during pregnancy cause the joints to become more relaxed, which increases the risk for injury — particularly if a woman makes sudden, quick movements.

Schaffir said that, because of these changes, he did not think that Williams would be able to continue to play at her usual high level in the later stages of her pregnancy.

"There are concerns [about] playing activities that involve quick turns and sharp movements in the end of pregnancy," and so pregnant women may have to stop or modify their play in these cases, he said.

All women who exercise in pregnancy should make sure to stay properly hydrated, because pregnant women may get dehydrated more quickly, Schaffir said. Pregnant women should also listen to their body while exercising — if they feel lightheaded, dizzy, fatigued or short of breath, they should stop what they're doing and rest, he said.

Original article on Live Science.

Testing to see if someone peed in the pool just got a little bit sweeter: Scientists in Canada have developed a new way to test for urine, and it involves measuring how sweet the water is.

That is, the researchers turned to an artificial sweetener called acesulfame potassium. Acesulfame potassium isn’t broken down in the body and is excreted in urine, according to the study. The compound persists in bodies of water and remains stable at various pH levels and temperatures.

The researchers hypothesized that it could be a good indicator of urine levels in pools.

Many compounds in urine can react with compounds in swimming pools, such as disinfectants, and form “disinfection byproducts.” Some studies suggest that these byproducts may be harmful to human health, though it’s unclear if coming into contact with them in a swimming pool is dangerous, the researchers wrote.

The potential that these compounds may have to be harmful inspired the researchers, led by Lindsay Blackstock, a doctoral student in analytical and environmental toxicology at the University of Alberta in Canada, to investigate a way to test for urine in the water. [Tips for Keeping Kids Safe in Swimming Pools]

Acesulfame potassium is found in many packaged foods, the researchers noted. In recent years, artificial sweeteners have been increasingly recognized as a source of environmental contamination.

On average, the concentration of acesulfame potassium in pee is 4,000 nanograms per milliliter, according to the study.

In the study, the researchers collected samples from a total of 22 swimming pools and eight hot tubs in two Canadian cities. In addition, they collected samples of the municipal tap water in each city, as this was the source used to fill the pools and hot tubs.

They found that the concentrations of acesulfame potassium in the pools and hot tubs ranged from 30 nanograms per liter up to 7,110 ng/L. This variation may be explained by a number of factors, including how the water was filtered in the pool, and the number of people swimming (and potentially peeing) in it, the researchers noted.

The concentration of the artificial sweetener found in the municipal tap water was much lower, however: It ranged from 6 ng/L to 15 ng/L, according to the study — meaning that the concentrations of acesulfame potassium in swimming pools and hot tubs was up to 571 times greater than what was found in the tap water.

In a separate experiment, the researchers took 15 samples from two swimming pools over a three-week period. One pool held 220,000 gallons of water (one-third the size of an Olympic pool) and one pool held half that, with 110,000 gallons of water. 

Using the acesulfame potassium concentrations as a guide, they estimated that, on average, the smaller swimming pool contained about 30 liters (7.9 gallons) of pee, and the larger pool contained about 75 liters (19.8 gallons) of pee.

The results of this method of testing for urine have not been confirmed by any other method. Currently, there is no recommended way of testing for urine in pools.

The study was published today (March 1) in the journal Environmental Science & Technology Letters.

Editor's note: This story was updated on July 12 to correct the name of the artificial sweetener used in the study. The artificial sweetener was acesulfame potassium, not aspartame potassium. 

Originally published on Live Science.

This Sunday, the New England Patriots and the Atlanta Falcons will face off in the Super Bowl, battling for the championship on a turf field at Houston's NRG Stadium. Does the field's surface type — grass or turf — affect players' injury rates?

One of the benefits of artificial turf is that the surface is more uniform — free of things like potholes, said Brian Dorfman, a kinesiologist who owns an injury rehabilitation practice in California and works with both professional and Olympic athletes.

"Generally, the issues with grass surfaces are that they are not a perfect surface," Dorfman told Live Science. [5 Ways Science Could Make Football Safer]

However, if a grass field is smooth and lacks uneven bumps, then it may actually be safer for athletes, Dorfman said. That’s because grass is "a pretty forgiving surface," he added.

A few different studies have looked into the injury rates of athletes playing on grass and turf surfaces, and generally have found that neither surface leads to significantly more injuries than the other.

For instance, one study, published in the British Journal of Sports Medicine in 2006, found that, for 10 elite European soccer teams, the number of injuries during both training and games did not differ based on whether the athletes played on grass or turf.

Another study, published in 2007, also in the British Journal of Sports Medicine, looked at injury rates of 2,020 female soccer players over the course of one season, and found that injury rates on both artificial turf and grass were relatively similar.

The studies both found some slight increase in risk when it came to ankle injuries on turf. In the 2006 study, the risk of an ankle sprain was slightly greater in matches played on artificial turf versus grass (a ratio of about 4.83 injuries per 1,000 match hours played for artificial turf, to 2.66 injuries per 1,000 match hours played for grass). The researchers of the 2007 study also found that slightly more ankle ligament injuries occurred on artificial turf compared with grass.

This may be because turf surfaces are stiffer than grass surfaces, which can affect impact forces on the body's bones, muscles, tendons and ligaments, according to the 2007 study. Similarly, the friction between shoes and surfaces is higher on turf than on grass surfaces, which can affect rates of ankle and knee injuries, the authors of the study said.

Dorfman agrees, noting that ankle, knee and head injuries can be exacerbated on turf, which is a harder surface than grass. Turf also "tends to be a little sticky, so you can't get the natural slide," Dorfman said. This could affect ankle, toe and knee joints, he added. Finally, athletes who compete and train on turf are likely to experience soreness in their legs and lower back, given the harder surface, he said.

Numerous other factors, however, are likely to play just as great or even greater a role in injuries, including weather conditions, quality of the surface (whether it's grass or turf), an athlete's fitness level and impacts between players, the 2007 study noted.

Ultimately, Dorfman said, risk of injury doesn't just come down to surface type, but also biomechanics: The greatest athletes know how to move their bodies in the most efficient, safest way possible, properly aligning their bones and muscles and reducing the risk of injury.

"If I could change one thing to make less injuries, biomechanics would make a bigger change than the turf," he said.

Originally published on Live Science.

Seattle Seahawks fans' enthusiastic stomping and cheering at CenturyLink Field during the NFL playoff season is so powerful it can be felt by sensitive earthquake-detection equipment. And seismologists made special preparations to record the crowd noise that accompanied an important game on Saturday (Jan. 7) against the Detroit Lions.

The Pacific Northwest Seismic Network (PNSN) installed an array of seismometers (equipment that visualizes shaking as waves) at several stations throughout the stadium, in anticipation of the tremors that Seahawks followers have become famous for generating. PNSN shared web displays of the wave readings so that viewers at home could track the boisterous celebrations in real time — in fact, the seismographs were visible several seconds before the cheering appeared on TV, PNSN reported on its website. [The 10 Biggest Earthquakes in History]

Preliminary analysis of the Jan. 7 data revealed that the largest recorded seismic signal emerged shortly after 8 p.m. local time during a play toward the end of the game, when Seahawks quarterback Russell Wilson threw a touchdown pass to wide receiver Doug Baldwin. The signal lasted for about 30 seconds, and some shaking continued after the main activity subsided, PNSN reported on their website.

"Beast Quake"

Seahawks fans' reputation for earth-shaking displays erupted during a game on Jan. 8, 2011, when they produced what became known as the "Beast Quake." Their raucous response to a 67-yard touchdown vibrated the stadium so strongly that it registered as a magnitude-2 quake on equipment that was located about a block away, part of a network that spans the Pacific Northwest to monitor earthquake faults and volcanos for hazardous rumbling.

Since then, scientists have been collecting readings during select games at CenturyLink Field, noting how the stadium responds to the shaking and how that reverberates through the ground nearby. Their efforts allow them to test new equipment and software, and develop tools and strategies to improve responses to earthquakes, according to John Vidale, director of PNSN, and a professor of seismology with the department of Earth and Space Sciences at the University of Washington.

As PNSN explained on its website, "Earthquakes are not predictable, but Seahawk fan enthusiasm is."  

An array of seismometers

For the Jan. 7 Seahawks game against the Lions, Vidale and his colleagues seeded the stadium with six seismometers, which will remain in place for two more weeks, in case another testing opportunity, such as a game, arises, Vidale said.

During the game, waveform data is displayed live on the PNSN website through software called QuickShake, which people could use to follow wave amplitude and frequency changes.

Response time of the software to ground motion is faster than ever before — about 1 to 1.5 seconds, compared with 2 to 3 seconds last year, Vidale said.

Tracking quakes from the cloud

The scientists also shifted the software from running in the lab to running in the cloud, to determine if the virtual storage space could support thousands of people looking at it and still deliver information, which would be critical during an actual earthquake.

"These aren't the alerts that we'd send out, but they're related to the early warning system we're building, and they're related to how we make sure our equipment is functioning properly in the field, so that everything's working when we really need it," Vidale said.

Raising public awareness about earthquake preparedness is another important part of this initiative. Earthquakes are challenging to prepare for because they strike so unpredictably, so PNSN seismologists are constantly investigating ways to inform the public about earthquake risks and safety, Vidale told Live Science.

Original article on Live Science.

It might not be obvious to those who spend Saturdays cheering on their alma mater on the gridiron, but playing college football is linked to changes that negatively affect the heart.

However, not all players are affected equally — position makes a difference, a new study finds.

In the research, linemen were more likely to develop high blood pressure over the course of a season than players in other positions were, according to the study, published Dec. 5 in the journal JACC: Cardiovascular Imaging. [The Science of Football: Which Positions Take the Hardest Hits?]

Linemen tend to be bigger than other players on the field, as their primary job is to block and tackle. Indeed, the linemen in the study had, on average, higher BMIs than players in other positions, such as quarterbacks and wide receivers.

Previous research has shown that former professional linemen have an increased risk of dying from heart disease, but scientists weren't sure what caused this increased risk, the new study said.

This research included 87 freshmen athletes who played on the Harvard University varsity football team between 2008 and 2014. Before each football season began, the researchers measured the athletes' blood pressure and took images of their hearts, according to the study. The same measurements were taken after the season ended.

The researchers looked to see which players had "prehypertension," meaning that their blood pressure fell between what's considered "normal" (120/80 mm Hg) and what's considered hypertension (140/90 mm Hg).

Results showed that before the season began, the rates of prehypertension were similar between linemen and nonlinemen: 57 percent of the linemen had prehypertension, and 51 percent of the nonlinemen had the condition, the researchers wrote.

But at the end of the season, 60 percent of the linemen had prehypertension and another 30 percent had hypertension, while in the nonlinemen, the rates remained the same as in the preseason, the researchers found.

In addition, at the end of the season, cardiac imaging showed changes to the structures of the linemen's hearts that were "concerning in this population of young, otherwise healthy athletes and" that raise "questions about long-term health implications," Dr. Aaron Baggish, the associate director of the Cardiovascular Performance Program at Massachusetts General Hospital and the senior author of the study, said in a statement.

More research is needed on how sports may affect athletes' hearts, Dr. William Zoghbi, the chairman of the cardiology department at Houston Methodist DeBakey Heart and Vascular Center, said an editorial accompanying the new findings. Zoghbi was not involved in the study. 

Originally published on Live Science.

Many types of exercise are linked to a lower risk of premature death, but activities like racquet sports, swimming and aerobics seem best at improving people's chances of staving off an early demise, according to a new study.

Researchers found that people in the study who regularly played racquet sports had a 47 percent lower risk of dying over the course of the nine-year study than people who did not regularly engage in such sports. And people who regularly went swimming had a 28 percent lower risk of an early death during the study than those who did not regularly swim, the researchers found.

Moreover, people who regularly did aerobics had a 27 percent lower risk of dying during the course of the nine-year study than people who did not regularly do such activity, the researchers found. [The 4 Types of Exercise You Need to Be Healthy]

"These findings demonstrate that participation in specific sports may have significant benefits for public health," the researchers, at the UKK Institute in Finland and the University of Sydney in Australia, wrote in the study, published Tuesday (Nov. 29) in the British Journal of Sports Medicine.

In the study, the researchers asked more than 80,000 people whether they had exercised in the past month and, if they had, what types of exercise they had done. The people were 52 years old, on average, at the start of the study; the researchers then followed the participants for nine years, on average. During the course of the study, 8,790 of the participants died.

The researchers found that the people who reported swimming, doing aerobics or playing racquet sports in the past month at the start of the study were less likely to die during the study period than those who had not engaged in these activities in the past month at the start of the study.

In addition, the researchers found that the people who reported cycling in the past month at the start of the study were 15 percent less likely to die during the study than those who did not report cycling in the past month at the start of the study. [The Odds of Dying from Shark Attacks, Tsunamis & Dozens of Other Causes]

Those study participants who ran or jogged, and those who played football or rugby did not have a lower risk of dying during the study period than those who did not engage in these sports, the researchers also found.

However, the results don't prove that engaging in certain types of physical activities directly causes people to live longer, the researchers noted. Rather, the findings suggest that there is a link between these activities and a longer life, the study said.

The research did not look at why certain sports may help people to live longer than others.

Originally published on Live Science.

The best way for competitive swimmers to hold their fingers is to spread them slightly apart so they rake the water, a new study finds.

In the hunt for the technique that could bring the fastest freestyle swimming, previous research hinted that swimmers could improve their efficiency by spreading their fingers apart, but much remained uncertain how this might work and how much swimmers needed to spread their fingers to benefit.

To solve this mystery, fluid dynamicists investigated both virtual models of human arms in computer simulations and 3D-printed models of human arms in wind-tunnel experiments. They analyzed the forces that these models experienced at five different levels of finger spreading: At zero degrees of spread, where all the fingers were pressed together like a paddle, through progressively wider 5-degree intervals all the way to 20 degrees of spread. [The 4 Types of Exercise You Need to Be Healthy]

The best results were seen with 10-degree finger spreading in both computer simulations and wind-tunnel experiments, the researchers said.

The researchers explained that as fingers spread apart, some water slips through them. However, the resulting turbulence can limit the flow of water between the fingers. As such, slight finger spreading can effectively increase the surface area of a hand. Up to a certain point, the benefit from this effective boost in surface area outweighs the effect of water lost between the fingers, said study co-author Josje van Houwelingen, a swimming fluid dynamicist at the Eindhoven University of Technology in the Netherlands.

In the study, even 5-degree finger spreading reduced the amount of drag that arms experience by 2 percent in computer simulations and 5 percent in wind-tunnel experiments.

"Using optimal finger-spreading might give a competitive edge," van Houwelingen told Live Science.

Although these effects are subtle, they could make a big difference in races between elite swimmers. "When you are a top swimmer, this very small effect, only a few percent, can make the difference between a gold medal and no medal at all," van Houwelingen said in a statement.

"We made a rough, and a little bit exaggerated, estimate for the possible improvement on the 50-meter freestyle," van Houwelingen said. "This resulted in a 0.6-second improvement." In contrast, she noted that the time difference between first and sixth place at the woman's 50-meter freestyle final at the 2016 Summer Olympics in Rio de Janeiro was just 0.12 seconds. [10 Biggest Doping Scandals in Olympics History]

Van Houwelingen noted that she was a swimmer herself, and tried the raking technique during swimming. She found it difficult to keep her fingers spread a constant distance from each other, "but since elite swimmers can also optimize their starting position up to 1 degree, they most probably also can also apply something of this knowledge to their technique."

The researchers noted that their research involved arms moving somewhat unrealistically at constant speeds through fluids. They now plan to put 3D-printed arms in a big water tank and see what forces they experience when they perform more realistic swimming movements using a robot. [Infographic: Body Types of Olympic Athletes]

The scientists detailed their findings Monday (Nov. 21) at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Portland, Oregon.

Original article on Live Science.

Health Myths

Despite what you may have heard, drinking eight glasses of water a day isn't the key to good health. Also, neglecting to wear a coat on a cold day won't make you sick. And — you might want to sit down for this — pregnancy doesn't last nine months.

Health-related myths are often repeated as fact, even though any diligent Google search will reveal the truth behind these fallacies. Here are 26 of the most common medical myths, debunked.

Myth: Vaccines can cause the flu (and autism).

Although the body can develop a low-grade fever in response to any vaccine, rumors that a flu shot can cause the flu are "an outright lie," said Dr. Rachel Vreeman, co-author of "Don't Swallow Your Gum! Myths, Half-Truths, and Outright Lies about Your Body and Health" (St. Martin's Griffin, 2009).

The flu shot does contain dead flu viruses, but they are, well, dead. "A dead virus cannot be resurrected to cause the flu," Vreeman told Live Science in 2010. As for vaccines causing autism, this myth was started in 1998with an article in the journal The Lancet. In the study, the parents of eight (yes, only eight) children with autism said they believed their children acquired the condition after they received a vaccination against measles, mumps and rubella (the MMR vaccine). Since then, rumors have run rampant despite the results of many studies. For example, a 2002 study in The New England Journal of Medicine of 530,000 (yes, a whopping 530,000) children found no link between vaccinations and the risk of a child developing autism.

Unfortunately, the endurance of this myth continues to eat up time and funding dollars that could be used to make advances in autism, rather than proving, over and over again, that vaccinations do not cause the condition, said Vreeman, who also researches pediatric conditions.

Myth: Supplements always make you healthier.

Vitamin supplements may be not only ineffectual but even dangerous, studies have shown. For example, a study published in 2016 showed that some older women who take calcium supplements may face an increased risk of dementia. And in a huge review of 20 years of supplement research published in 2015, researchers found that taking high doses of vitamins may be linked with an increased risk of cancer.

Aside from these possible long-term risks, reports have suggested that supplements can cause damage in the short term too. A report published in 2016 found that a man in Pennsylvania who took Ayurvedic herbal supplement developed lead poisoning. Another report, also published in 2016, showed that a 4-year-old boy in England went to the ER after taking a slew of "natural" supplements, and developing a condition called vitamin D toxicity.

"The FDA does not require supplements to be regulated in the same way that drugs are, which can be a real problem," Vreeman said in 2010. As a result, the safety of many supplements has not been rigorously studied. Furthermore, supplement bottles can sport unsubstantiated claims and even make errors in dosage recommendations, she said.

It's a better idea to get your vitamins and other nutrients from eating real food, rather than taking a pill, she said.

"A vitamin pill is not the answer," Vreeman said. "Eating more healthily in general is the answer."

Myth: Cold weather makes you sick.

"This myth is common around the world, but it is just not true," Vreeman told Live Science. Studies have shown we may feel more cold symptoms — real or imaginary — when we are chilled (after all, a cold is called a "cold" for a reason), but the temperature itself does not make us more susceptible to viruses. This has been known since at least 1968, when a study in The New England Journal of Medicine showed what happened when researchers exposed chilly people to the rhinovirus (one cause of the common cold).

It turned out that whether they were shivering in a frigid room or in an icy bath, people were no more likely to get sick after sniffing cold germs than they were at more comfortable temperatures.

Vreeman said that cold air also does not make a difference in people's recovery time from a cold. In fact, although the research is in its early stages, "it is possible that being exposed to cold may even help your body in some way," she said.

However, its unclear how chilly conditions might affect the germs themselves. Research has shown that two common causes of colds — rhinoviruses and coronaviruses — may thrive at colder temperatures, and that the flu may spread most effectively under cold, dry conditions.

Some scientists speculate that colds are more common in cooler months because people stay indoors more, interacting more closely with one another and giving germs more opportunities to spread.

Myth: We use only 10 percent of our brains.

Motivational speakers and other self-help gurus have been promoting this one since as early as 1907, as a way to encourage people to tap into some latent capacity, explained Vreeman and the co-author of her book, Dr. Aaron Carroll, both of the Indiana University School of Medicine, write in the book. But these people were not basing the proclamation on sound science.

Today, scientists can look at any brain scan, measuring activity at any given time, and have a big laugh at this myth. "You just don't see big dormant areas," Vreeman said. The idea lingers in popular culture because "we want to think we haven't reached our full potential," Vreeman said.

Myth: Sugar turns kids into little monsters.

It can be hard to find a parent who does not believe this, Vreeman said. "But it is in their heads." In one particularly clever study among a slew of studies finding sugar's nil effect on unruliness, kids were given Kool-Aid sweetened with aspartame, a compound that contains no sugar. Researchers told half of the parents the Kool-Aid contained sugar, and told the other half the truth.

The parents in the study who thought their kids were riding a sugar high reported their children were uncontrollable and overactive. But a sensor on the kids' wrists that measured activity level said the opposite: The kids were actually acting subdued. The study was published in the Journal of Abnormal Child Psychology in 1994.

Sugar is often given at times when the rules are loosened and there are lots of other kids around, like birthday parties and holidays, Carroll told Live Science. These factors may be behind the myth's persistence in popular culture, he said.

Myth: You need to stay awake if you've had a concussion.

Anyone who may have a concussion should seek medical attention, but the condition is rarely severe or life-threatening. Warnings that people need to stay awake after incurring a concussion  most likely grew out of a misunderstanding about a particular type of head injury — one that involves brain bleeding and that causes people to have a "lucid period," followed by a coma or even death. But this is very uncommon and doesn't pertain to people with normal concussions, Vreeman said.

"If you've been evaluated by a doctor, and he has said that you have a mild regular concussion, you don't need to worry that someone has to wake you up every hour," she said.

Myth: Chewing gum stays in your stomach for 7 years.

Although it is true that many of the ingredients in gum — such as elastomers, resins and waxes — are indigestible, that does not mean they hang out in your guts for seven years. Plenty of what you eat — even things you are recommended to eat, such as fiber — is indigestible. But the digestive system is a robust piece of organic machinery, and anything it can't absorb, it moves along. Despite the stickiness and strange consistency of gum, "it passes right through your digestive tract and into the toilet," Vreeman explained.

Myth: Reading in the dark or sitting too close to the TV ruins your eyesight.

Dim light — or alternatively, staring into the multicolored tube at close range — can undoubtedly make your eyes work so hard they hurt. But there is no evidence that these practices cause long-term damage, Vreeman said. The TV myth may have started in the 1960s, and at that time, it may have been true. Some early color TV sets emitted high amounts of radiation that could have caused eye damage, but this problem has long been remedied, and today's TV and computer monitors are relatively safe, she said.

If you or your child tend to sit so close to the computer or TV that it hurts the eyes, it may be a good idea to get checked for nearsightedness. However, sitting too close does not create a need for glasses even if getting glasses can remedy the habit.

Myth: You should drink at least 8 glasses of water a day.

"In general, we are not all walking around in a dehydrated state," Vreeman said, adding that our bodies are very good at regulating our fluid levels. The eight-glasses-a-day myth likely started in 1945, when the Food and Nutrition Board of the National Research Council said adults should take in about 2.5 liters of water a day (equivalent to about eight glasses, or two-thirds of a gallon). Although most media outlets reported that as fact and stopped there, the council actually went on to explain that most of the 2.5 liters comes from food. According to Vreeman, the recommendation should be amended to the following: Drink or eat about eight glasses of fluid a day.

Myth: You should wait an hour after eating before you go swimming.

This myth has ruined many summer afternoons, forcing young and old to swelter in the heat while cool waters beckoned, all because they were careless enough to down a PB&J. Let the ban be lifted: There is no special reason not to swim after eating, Vreeman said.

It's true that any type of vigorous exercise can be uncomfortable (although not dangerous) after an overwhelming feast. But for most of us whose waterfront dining experience includes sand-dusted chips and soggy sandwiches, that is hardly a concern. And cramps can happen anytime, whether you've eaten or not. If you are swimming in waters so rough that a charley horse will mean the death of you, you should probably swim elsewhere. Just don't forget the picnic!

Myth: Fingernails and hair continue to grow after death.

This myth is actually just a misperception, and for many years, most physicians couldn't disprove it, even though they couldn't quite explain it. Here's what really happens to your nails and hair after you die: 

"As the body's skin is drying out, soft tissue, especially skin, is retracting," Vreeman said. "The nails appear much more prominent as the skin dries out. The same is true, but less obvious, with hair. As the skin is shrinking back, the hair looks more prominent or sticks up a bit."

Myth: Shaved hair grows back faster, coarser and darker.

Here's a myth you can debunk yourself by paying attention to your own hair after shaving. You may notice that new hair grows in with a blunt edge on top. Over time, that blunt edge gets worn down, making it seem thicker than it really is. But why might recently shaved hairs seem darker than their nonshaved counterparts? It could be that those newly spouted hairs haven't yet been bleached by the sun, Vreeman said.

But if you don't trust your own experimental skills, there's other evidence that this myth isn't reality. A clinical trial conducted in 1928 compared hair growth  in shaved patches to hair growth in nonshaved patches. The study found that new hair that replaced shaved hair wasn't darker or thicker, nor did it grow faster. More recent studies  have confirmed that one.

Myth: Eating turkey makes you drowsy.

Your excuse for taking a nap after dinner on Thanksgiving just went out the window. While turkey does contain a chemical called tryptophan that is known to cause drowsiness, your serving of Thanksgiving bird doesn't contain any more of the chemical than a similar-size serving of chicken or beef, Martha Stipanuk, a professor of molecular nutrition at Cornell University, told NPR in 2008.

So why do people feel so sleepy after a Thanksgiving feast? It could be the overall quantity of food you eat on this holiday that makes you drowsy. Those heaping mounds of carbohydrates on your plate (think dinner rolls and mashed potatoes), plus a few alcoholic beverages, will almost certainly make you feel tired, according to experts.

Myth: Ulcers are caused by spicy food and stress.

If you think your ulcers are acting up because of the curry you ate last night for dinner, think again. Although doctors once believed that ulcers were caused by stress, lifestyle choices or spicy foods, they now know that most ulcers are actually caused by the bacterium Helicobacter pylori.

Ulcers — sores that develop in the lining of the esophagus, stomach or the first part of the small intestine — can also be caused by certain medicines. Aspirin and iron tablets are the most common culprits, according to Dr. Arun Swaminath, director of the Inflammatory Bowel Disease Program at Lenox Hill Hospital in New York City. 

Myth: A woman can't get pregnant during her period.

Although it's unlikely that a woman will conceive during menstruation, it isn't impossible, according to Carroll. Sperm can live inside a woman's body for up to a week, and ovulation can occur soon after (or even during) the "bleeding" phase of a woman's menstrual cycle. That makes it possible for a woman to become pregnant if she has sex either during her period or shortly after it ends. 

Myth: You lose most of your body heat through your head.

Don't believe the hat salesman: You don't lose most of your body heat through your head.

In 2006, scientists decided to debunk this myth  once and for all. They found that the amount of body heat lost through a person's head is only about 7 to 10 percent of total body heat. In other words, body heat loss from the head is proportional to the amount of skin on the average human head.

Myth: Going out in the cold with wet hair will make you sick.

Don't have time to dry your hair before leaving the house on a cold day? Don't worry about it! Though lots of people might tell you that a wet head, plus cold air, is bound to equal a head cold, that's simply not the case, according to Weiss. Germs such as viruses and bacteria, not temperature changes, make people sick. So although you might be a bit chilly if you leave home with wet hair on a winter day, that doesn't mean you'll get sick, he said.

However, a study published in 2015 in the journal Proceeding of the National Academy of Sciences does suggest that rhinoviruses (the viruses behind the common cold) may take advantage of cold weather. Researchers found that cold temperatures might make it easier for these cold-causing viruses to replicate by diminishing the body's antiviral immune responses.

Myth: Deaths by suicide increase over the holidays.

Here's a myth you've probably heard every December: The number of people who die by suicide increases during the holiday season. But that's actually not the case. In fact, suicide rates in the U.S. are lowest in December, according to the Centers for Disease Control and Prevention's (CDC) National Center for Health Statistics.

One reason for this myth may be the way the media covers deaths from suicide. A recent analysis of media reports written during the 2013 holiday season found that 70 percent of published articles perpetuated this myth.

The number for the national suicide hotline is 800-273-8255.

Myth: Poinsettias are toxic.

Poinsettias aren't toxic. We repeat: Those beautiful flowers you've been so wary of keeping in your home during the holidays (lest they poison pets or children) are not toxic.

The plants can make people sick, but there have been no definitive cases of a person dying from exposure to a poinsettia plant.In a paper  published in the Southern Medical Journal in 1996, researchers reviewed 22,793 cases of poinsettia exposure that were reported to poison control centers over a seven-year period. They found that not one of those cases was fatal. The most severe reactions reported were stomachaches and cramping.

The myth about poinsettias being toxic may have come from a case, reported in 1919, of a 2-year-old in Hawaii who allegedly died after ingesting parts of the plant, according to a 2012 article in the Western Journal of Emergency Medicine. But the child's death was never confirmed, nor was the cause of death.

Myth: Chicken noodle soup cures … everything.

p> Everybody's heard that chicken soup is supposedly the best cure for whatever ails you. But does this delicious food really help you get better when you're sick?

Unfortunately, no, Weiss said. The combination of hot broth and yummy veggies is more of a comfort than a cure, he said. However, some research suggests that chicken noodle soup may work well as a placebo. In other words, it may convince you that you're getting better. So keep slurping!

Myth: Eating at night makes you fat.

Don't feel guilty the next time you reach into the fridge for a midnight snack.

Though eating late at night has been associated with obesity, this eating behavior doesn't actually cause obesity.

"You shouldn't be afraid to have that midnight snack anymore than a mid-day or mid-morning snack," Carroll said.

Myth: Psychiatric and emergency room visits increase during the full moon.

Myths about the moon's effect on human behavior have been around since at least the Middle Ages, but science doesn't support full-moon folklore. For example, one popular myth states that emergency psychiatric visits increase around the full moon. But that's just not the case.

A2005 study by Mayo Clinic researchers looked at how many patients checked into a psychiatric emergency department between 6 p.m. and 6 a.m. over several years. The researchers found no statistical difference in the number of emergency psychiatric visits on the three nights surrounding full moons versus other nights of the lunar cycle.

And regular emergency-room visits are not any more common during a full moon, either. In 1996, researchers at Northwestern University examined 150,999 records of emergency-room visits to a suburban hospital. Their study found no significant difference between the number of visits during the full moon versus other nights.

Myth: Taking probiotics helps prevent colds.

Sure, probiotics won't make you sick, but they won't keep you from catching a cold, either, according to Dr. Patricia Hibberd, a professor of pediatrics and chief of global health at MassGeneral Hospital for Children in Boston.

Although preliminary research does suggest that probiotics could possibly help ward off colds, no high-quality trials support this claim, Hibberd told Live Science in 2014. 

Myth: Babies get fevers when they are teething.

This is one of those myths that every parent has heard: Babies get fevers when they teethe. But this medical myth is both false and potentially dangerous, according to Vreeman. Parents shouldn't write off a baby's fever as due to teething, she warned.

Research has not shown a strong relationship between teething and high body temperatures, so if your tot has a fever, it might be time to visit the doctor.

Myth: Pregnancy lasts nine months.

Everyone knows that pregnancy lasts nine months. But everyone is wrong about this "fact."

"It's actually more like nine and a half months," said Dr. Joanne Stone, an obstetrician at Mount Sinai School of Medicine in New York City and co-author of "Pregnancy for Dummies" (For Dummies, 2009).

Doctors typically measure a full-term pregnancy as lasting 40 weeks, counting from the first day of a woman's last period. But women usually become fertile 10 to 16 days after their period starts. So by this method of counting, the first two weeks of most pregnancies actually take place before a woman has conceived. And just to confuse the matter even more, researchers have found that the amount of time a healthy pregnancy lasts can vary by as much as five weeks. 

Original on Live Science.

Revelations of doping typically provoke moral outrage. The received view is that doping is morally wrong because it’s cheating, and those caught doing it should be punished.

The rhetoric of the media, the World Anti-Doping Association (WADA) and sporting officials – and, in the Rio Games, some athletes themselves – all embody this idea. But why is doping morally wrong? Would it be morally wrong if it wasn’t against the rules?

Athletes who dope are seeking to gain a competitive advantage over their rivals. But athletes seek to gain competitive advantages in numerous ways and many of these are not banned.

If it’s wrong to enhance your performance by doping, why is it not also wrong to enhance your performance by taking dietary supplements, for instance, or carb-loading, or by training at altitude?

Identifying the moral culprit

Banned substances are typically synthetic so they artificially enhance athletic performance. If the point of sport is to test the natural limits of human nature then, by artificially extending those limits, doping is at odds with the essence of sport.

Many banned substances, such as anabolic steroids, are synthetic. But many naturally occurring substances, such as Erythropoietin (EPO), and techniques that involve no synthetic substances, such as blood doping, are also banned.

Conversely, many synthetic enhancements are permitted. Think of the latest in streamlined clothing, cycling helmets, and running shoes.

Another problem could be the intended effect. Blood doping is supposed to increase red blood cell supply, thereby increasing stamina. But other means of achieving this effect are permitted by WADA.

Altitude tents, for instance, are currently not on WADA’s prohibited list. But even if they were, would WADA also prohibit athletes from going to high-altitude locations to train, which has the same effect?

Perhaps the real problem lies with the coercive effect of doping: the so-called “arms race”. If some athletes are at an advantage because they are doping, it puts pressure on others to dope too.

But elite sport is already highly coercive.

To remain competitive, athletes have to submit themselves to harsh training regimes and controlled diets that potentially cause long-term harm. If such measures produce better results, then all athletes have to adopt these measures.

Yet no one suggests there’s anything wrong with this kind of coercion in sport.

Cheating and unfair advantage

The moral outrage points to a simpler reason for the wrongness of doping. Doping is cheating because it’s against the rules. But why is it against the rules? Because it’s cheating, of course!

This argument moves in an embarrassingly small circle. And it doesn’t help to expand the circle: doping is cheating, and cheating is wrong, so doping is wrong. But why is doping cheating? Because it is banned.

And so we arrive at the nub of the problem: what justifies the rule banning doping in the first place?

The most obvious answer is that doping confers an unfair advantage. But the advantage is only unfairly gained because doping is banned: by contravening the rules the doping athlete gets an advantage that her more rule-abiding competitors don’t get.

There are lots of ways in which athletes seek to gain advantage over their rivals: by using the best coaches, training techniques, dietary regimes, and so on. But we view these methods of gaining advantage as fair because they are within the rules.

The unfairness of the advantage secured by doping seems to be conferred simply by the fact that it is against the rules, and therefore cheating.

A way forward

If there’s no prospect of a clear, non-arbitrary justification for why doping is wrong, one option would be to allow doping in some form or other. Many find that unappealing, presumably because the moral intuition that doping is wrong is so strongly felt.

But if it is to be maintained, we need to find another way of justifying it.

Here’s one suggestion: give up the view that doping is intrinsically morally wrong, and replace it with the view that the ban on doping is justified in the same way that the rules of any particular sport are justified.

The rules of any sport are arbitrarily designed with various aims in mind: to facilitate an even contest between the competitors; to reward certain skills and virtues; to produce an entertaining spectacle; and so on. They have no intrinsic moral significance.

The rule banning doping in any given sport could simply be one of these rules, no more morally weighty than the offside rule in football. Doping would then be cheating in just the same way as taking the subway for part of a marathon would be cheating.

The International Olympic Committee’s recent decision not to ban the entire Russian team, leaving international sporting federations to rule on individual athletes, can be seen as a move in this direction. Rather than adopting a uniform, homogeneous view on doping across all sports, it has delegated to individual sporting bodies decisions about how to deal with doping athletes within that sport.

Perhaps we should curb our moral outrage. Rules against doping in a particular sport are no more morally weighty than any other rule in that sport.

Heather Dyke, LSE Fellow in the Department of Philosophy, Logic and Scientific Method, London School of Economics and Political Science

This article was originally published on The Conversation. Read the original article.

A competitive edge

Some athletes seeking to push the boundaries of their personal performance may find it tempting to grab a competitive advantage by looking beyond their training and nutrition. And on the world's biggest stage, at the Olympic Games, there are all too many instances of athletes who have turned to the use of a chemical advantage to gain a leg up on their fellow competitors.

Most performance-enhancing substances are banned in sports, but there are still many that either can't be reliably detected or that have yet to be classified. In Olympics history, cheaters often face swift punishment, but sometimes, official rulings take years to resolve. Secondary drug tests may catch the offender after the competition, or arbitration may drag on. And no matter how clearly the rules are defined, debates over what actions should be punished, and how severely, endure. [Doping at the Games: Why the Olympics Banned These Drugs]

Here are some of the biggest doping scandals in modern Olympics history.

Lance Armstrong (USA), 2000

After his first Tour de France victory in 1999, American cyclist and cancer survivor Lance Armstrong immediately became an icon of resilience. As his popularity grew, so did the profile of Livestrong, his charitable cancer organization. But his seven Tour de France titles (from 1999 to 2005) were revoked in 2012 after years of suspicion culminated in the exposure of an elaborate, multifaceted doping scheme within Armstrong's U.S. Postal Service team.

In light of that evidence, in 2013, the International Olympic Committee nullified the bronze medal Armstrong won for the men's road time trial at the 2000 Summer Olympics in Sydney, Australia. Soon afterward, Armstrong delivered his first public admission of guilt in a terse televised interview with Oprah Winfrey. He did not return the medal for another eight months, reported NPR.

Luiza Galiulina (Uzbekistan), 2012

Luiza Galiulina was a gymnast from Uzbekistan who in 2012 was set to make her second appearance at the Summer Olympics in London. After testing positive for furosemide, a diuretic that is considered to be a masking agent or weight-loss supplement, Galiulina was provisionally banned from the games. Galiulina denied knowingly taking the substance, and she said that her mother had given her a heart medication the previous month. Furosemide is also used to treat high blood pressure or congestive heart failure.

Galiulina missed a scheduled competition in artistic gymnastics due to the ban. Days later, when her backup sample also tested positive, she was removed from the Olympic Village, and afterward she was given a two-year suspension.

Marion Jones (USA), 2000

A 2003 investigation into the Bay Area Laboratory Co-operative (BALCO), which supplied steroids to a variety of high-profile athletes, led to suspicions that American sprinter Marion Jones had used performance-enhancing drugs. But, it wasn't until 2007 that Jones admitted to past use of a designer steroid known as "the clear." Jones said she began using the steroid just weeks before the 2000 Summer Olympics in Sydney.

Jones returned the five medals she won in those games, including gold medals in the 100-meter and 200-meter races, and the 4 x 400-meter relay. Jones had also nabbed bronze medals for long jump and the 4 x 100-meter relay. All of Jones' race results after Sept. 1, 2000, were expunged, and she was given a two-year ban.

In 2010, the Court of Arbitration for Sport ruled that Jones' relay teammates could keep their medals, based on rules in place at the time of competition.

Russian team, 2012, 2014 & 2016

Russian athletes have been dogged by doping suspicions at several Olympic Games, but these allegations were made worse by recent evidence of pervasiveand persistentdoping schemes, reported the New York Times. This includes the revelation of a sample-swapping systemto protect cheating athletes, in an effort to boost Russia's medal count when the country hosted the 2014 Winter Olympics in Sochi. 

Based on a report from the World Anti-Doping Agency, the International Olympic Committee said, "all Russian athletes … are considered to be affected by a system subverting and manipulating the anti-doping system." Yet,the organization left it to the governing bodies of each sport to determine the eligibilityof individual athletes. As a result, 271 of 389 Russian athleteswere cleared for competition at the 2016 Summer Olympics in Brazil, reported CNN.

The International Paralympic Committee banned the entire Russian federationfrom competing at the Rio Paralympics.

Ben Johnson (Canada), 1988

Three days after sprinting to glory in the 100-meter final at the 1988 Summer Olympics in Seoul, Korea, Canadian track star Ben Johnson was disqualified for a positive test for the steroid stanozolol. Johnson had set a new world record time of 9.79 seconds in the race. When the positive drug test was revealed, Johnson denied any wrongdoing, but later admitted to using a different steroid, furazabol, while training for the Olympics.

Johnson's records were removed and the gold medal was awarded to American Carl Lewis instead. In 1993, Johnson failed a second drug test, which turned up an elevated testosterone-to-epitestosterone ratio, and the International Amateur Athletic Federation, the governing body of Track and Field, banned him for life.

Nicklas Backstrom (Sweden), 2014

A positive test for pseudoephedrine kept Swedish hockey star Nicklas Backstrom out of the gold-medal game at the 2014 Winter Olympics in Sochi. Sweden criticized the timing of the suspension announcement, which came just hours before the game.

Olympic officials eventually determined that Backstrom hadn't intended to gain a competitive edge by taking a banned substance. The hockey player took medication at the advice of a team doctor and even declared its use in paperwork. Backstrom later received a medal and only a reprimand from the World Anti-Doping Agency. It was cold comfort: a short-handed Swedish team lost to Canada 3-0, taking silver.

Andreea Raducan (Romania), 2000

Romanian gymnast Andreea Raducan was disqualified and stripped of the gold medal she won in the all-round gymnastics competition at the 2000 Summer Olympics in Sydney, after she tested positive for pseudoephedrine. The drug, a stimulant that is the active ingredient in medicines such as Sudafed, was banned by the International Olympic Committee but not the International Gymnastics Federation.

Raducan, then 16, received the pseudoephedrine in cold medication from a team doctor, who was subsequently suspended for the next two Olympic games.

Earlier, Raducan had won gold in team gymnastics and a silver in the vault. She tested negative following those events and was allowed to keep the medals. In 2015, Raducan appealed the status of her all-around gymnastics gold medal to International Olympic Committee president Thomas Bach in person, but the result was not reinstated.

Tyson Gay (USA), 2012

American sprinter Tyson Gay was part of the silver-medal-winning 4 x 100–meter relay team at the 2012 Summer Olympics in London. But the next year, Gay failed three drug tests in rapid succession, prompting the erasure of results dating back to the London games. Gay, then 31, immediately dropped out of competition, returned his medal and cooperated with U. S. Anti-Doping Agency investigators. He served only a one-year suspension.

In 2015, the International Olympic Committee stripped Gay's relay teammates of their medals.

Ross Rebagliati (Canada), 1998

At the 1998 Winter Olympics in Nagano, Canadian snowboarder Ross Rebagliati won a gold medal in giant slalom. Rebagliati subsequently tested positive for marijuana, after which a series of Olympic boards voted to strip him of the medal. The ruling was unusual, because cannabis was not on the International Olympic Committee's list of banned substances at the time (it was added a couple of months after the games concluded), and it is not generally considered to be a performance-enhancing drug. An appeal to the Court of Arbitration for Sport was quickly rewarded, and Rebagliati was able to keep his medal.

Rebagliati is now the face of a marijuana dispensary branding company.

Johann Muhlegg (Spain), 2002

Cross-country skier Johann Muhlegg competed for his native Germany in three Olympics prior to representing Spain in the 2002 Winter Olympics in Salt Lake City. Muhlegg won gold in the 30-kilometer and 50-kilometer races, and the 10-kilometer pursuit, but after a positive test for darbepoetin, a then-new prescription drug that promotes red blood cell production, he was disqualified from the 50-kilometer race.

Other tests conducted throughout the competitions had been inconclusive, but Muhlegg was eventually stripped of his other medals as well.

Olympic officials in Rio de Janeiro announced this past weekend that they had found out why the water in two pools turned bright green, but their explanation has at least one chemist scratching her head.

The confusion comes down to an understanding of basic chemistry and swimming pool maintenance, said Susan Richardson, a professor of chemistry at the University of South Carolina and a former pool owner.

On Saturday (Aug. 13), Olympic officials said they had definitely found out why the water in two of the swimming pools turned an unusual green color, The New York Times reported.

"Someone, the officials said, mistakenly added 160 liters [42 gallons] of hydrogen peroxide on Aug. 5, neutralizing the chlorine and allowing the growth of 'organic compounds' that might have included algae," the Times said. [The Twisted Physics of 5 Olympic Sports]

But Richardson said that hydrogen peroxide — an antiseptic that kills bacteria — is not used in pools, as far as she is aware. Though Richardson isn't involved with the pool maintenance in Rio, she has based her response on news reports of the pools' colors.

And the official explanation offered at the Rio Olympics leaves her skeptical. "My suspicions are that somebody just wasn't paying attention, wasn't doing their job for making sure that there was enough chlorine in that pool," Richardson told Live Science. "And then they're trying to reach for some excuses."

If hydrogen peroxide were poured into a pool, it would quickly react with the chlorine-containing liquid bleach (NaOCl) in that pool and disable it, Richardson said. More specifically, hydrogen peroxide (H2O2) reacts with sodium hypochlorite (NaOCl) to form oxygen (O2), sodium chloride salt (NaCl) and water (H2O), she said.

As hydrogen peroxide reacts, it forms water (H20), and its signature bubbles, or fizz, which is really oxygen (O2), Richardson said.

If enough hydrogen peroxide were poured into a chlorinated pool, it would react with all of the bleach, until there wouldn't be any chlorine left to kill algae and other organisms that thrive in warm pools, she said.

"I didn't try to do the math," Richardson said. "Generally, in a pool, you're going to have anywhere from 1 to 4 parts per million of chlorine. If that 160 liters is enough to … react with the chlorine in this large pool, you will have probably degraded it [until there isn't any left]," she said.

However, when Olympic officials monitored the pools, they found the proper amount of chlorine in the pools, but didn't know that the chlorine wasn't working, Gustavo Nascimento, director of venue management for the Rio Olympics, told the Times.

This doesn't make sense, Richardson said. "Even if they had 'accidently' added hydrogen peroxide, they should be checking the chlorine level regularly," Richardson said. "They would have known immediately that the chlorine was gone."

Live Science reached out to Olympic press officials, but they did not immediately respond to comment. [In Living Color: A Gallery of Stunning Lakes]

Clear waters

It's likely that algae caused the green hue in the two Olympic pools, Richardson said. As someone who has owned a pool for more than 25 years, Richardson advised using large amounts of chlorine (called a chlorine shock) to get rid of the algae.

The chlorine shock kills algae, which die and fall to the bottom of the pool, she said. Then, the dead algae, which look like pieces of dirt, can be vacuumed up. The whole process would probably take about 24 hours for the Olympic-size pool, she added.

However, Rio officials opted for a faster solution, mainly so that the synchronized swimmers would have clear, blue water in time for their competition, the Times reported. Officials drained the 984,040-gallon (3,725,000 liters) pool with green water, and replaced it with clear water from a practice pool, the Times said. Nascimento, who spoke with the Times the day before the switch, estimated that it would take about 10 hours in total.

The switch clearly worked. British diver Tonia Couch tweeted that the water in the diving pool was a clear blue today (Aug. 15), saying, "Women's individual soon and the water isn't green anymore."

Original article on Live Science.

Fans of the Summer Olympics can't seem to get enough of American gymnast Simone Biles. The 19-year-old, who has already snagged gold medals in events for the team, individual all-round and vault competitions, can jump, flip and twist in ways the average person likely never will. Biles may make it look easy, but between all the different events that gymnasts have to master — from balance beam to the vault for women, and the pommel horse to the rings for men — what's the most challenging apparatus, according to science?

The answer is complicated, experts say. Generally, the gymnastic events that have the simplest explanation in terms of physics tend to also be the ones where athletes push the limits of physics the most.

For example, the physics of the pommel horse, an apparatus that male gymnasts must tackle, is easy to understand, said Jonas Contakos, a gymnastics coach with a Ph.D. in kinesiology and a master's in biomechanics. [Exercise and Weight Loss: The Science of Preserving Muscle Mass]

"The principle is quite simple: Keep your center of mass over the base of support at all times," Contakos told Live Science. In action, however, the ways in which gymnasts manipulate this basic principle places it among the most difficult events, he said.

The main challenge of the pommel horse, from a physics point of view, is dynamic stability, which means that the gymnast has to stay balanced enough to remain on the pommel while also moving his body.

"I think their center of mass is actually swinging around as their legs swing around, but they have to do that at the right rates, so, as they start to fall over, their legs are already having moved to the other side," said Jordan Gerton, an associate professor of bioengineering, physics and astronomy, and director of the Center for Science and Mathematics Education at the University of Utah. Basically, gymnasts are trying to keep from falling while making that objective as hard for themselves as possible.

Balance & core strength

The balance beam involves similar concepts. All the athlete has to do is keep her center of mass over the 4-inch-wide (10 centimeters) beam in order to balance. In other words, she could just stand there and not fall off, but it would be a rather uninteresting physics problem (and sport). Instead, gymnasts spin, twist and kick on the balance beam, testing the boundaries of the simple physics principle that could easily keep them stable. [7 Weird Facts About Balance]

Gerton said that the rings should also be counted as an event that's among the most advanced confrontations with physics that an athlete can face. The physics challenge that he notices specifically in this event is the lack of leverage that occurs when a gymnast pulls his body into a cross shape. It's one thing for a person to pull his body up to and through rings with arms that are near the body, but elite male gymnasts do this with their arms completely straight. The farther away from the body a gymnast holds his arms, the less leverage he has to move his body upward, Gerton said.

"[They] need to have an incredible amount of core strength to counteract that reduction in the leverage," he added.

In reality, there is no gymnastic event that is without extreme physics, experts say. Many of the events involve complicated balancing, such as handstands on the bars, and these maneuvers require the same coordination between center of mass and base of support as do the balance beam and pommel horse, but not as continually. Vault presents its own unique physics problem in the conversion of horizontal energy (running) into the vertical push and velocity required for the aerial skills gymnasts perform off the vault.

"You'll notice that people like Simone Biles do that really efficiently," Gerton said. "She takes her horizontal speed […] and she is able to convert that into vertical motion, which gives her a lot of time to do amazing things in the air."

Taking it to the floor

However, vaulting doesn't require the same level of balance as do some of the other apparatuses.

Tumbling is notable because, when viewed through the lens of physics, it's somewhat the opposite of pommel horse and balance beam: There are fewer constraints on the gymnasts' movements but the physics involved are harder to understand. Gymnasts in this event aren't fighting to balance on a small surface, but the complex physics of a floor routine is sometimes beyond comprehension.

"Tumbling on floor, from a physics perspective, is really, really complicated to deal with if you were to do an analysis of tumbling," Contakos said. In the world of biomechanics, motion analysis on tumbling is still at a really "primitive stage," he said. [The Twisted Physics of 5 Olympic Sports]

Floor exercises are hard to analyze, because they have more variables than the other events, according to Contakos. For example, the floor is spring-loaded and the gymnasts are moving their bodies in more diverse ways that blend jumping, balancing, twisting and turning.

Olympic gymnasts in every event are performing at the limits of what is physically possible and showing laymen and scientists alike that they can do more than anyone realized.

"As soon as we think we've hit a wall on that ability of just one simple principle, someone comes along and does it bigger and better and faster, or makes up a new skill," Contakos said.

And this year's gymnasts at the 2016 Summer Olympics in Rio de Janeiro are no exception.

"These amazing Olympic athletes are pushing the limits all the time," Gerton said. "They're figuring out how to push the physics to the edge as well."

Original article on Live Science.

Since the start of the modern Olympic Games in 1896, about one person in 2 million has won an Olympic gold medal. Michael Phelps now has 23 of them — more than double the number of gold medals won by any other individual in the history of the games.

This achievement seems superhuman, but just how out-of-the-ordinary is Phelps?

To find out, we can turn to a simple law of statistics. This basic math shows that Phelps' gold-medal count is so sky-high, it wouldn't have been predicted to occur, at least not for another 250 years. [The Science of Olympic Rivalries: Do Adversaries Help or Hurt?]

In the natural world, it has long been recognized that phenomena that vary over a wide range of values follow a remarkably simple pattern. Considering the size of earthquakes, for example, we know that there are numerous small temblors every day, with larger quakes being increasingly rare. Similarly, the size of meteor strikes, terrorist attacks and even the popularity of different websites follow a pattern where the biggest numbers rapidly become increasingly scarce. The amazing thing about these seemingly random events is that their rarity or frequency follows what is known as a power law distribution, a simple mathematical form that gives a straight line graph when plotted in a certain way. Even the popularity of words used in the English language follows such a "rule."  

So what does this have to do with Phelps and the list of multiple-gold-medal winners? A plot of the individuals who have won different numbers of gold medals in this way reveals this same power law distribution. Though nearly 6,000 people have won a single gold medal, fewer than 200 have won exactly three, and only four have won nine gold medals during their Olympic careers. Phelps is the only athlete to reach double figures.

A graph of the logarithm of both the number of people and the number of medals yields a relatively straight line — except for the 23 held by Phelps. That number is far to the right of the line, meaning that the number of medals is much greater than expected. In fact, the line crosses the "one individual" level at about 14, which would be about what we might expect based only on the medal counts of all other individuals.

Exactly how special is Phelps' achievement? The graph suggests we'd need to wait until almost five times as many medals have been awarded before we would reasonably expect someone to reach a total of 23. At the present rate of about 100 gold medals per year (average of Summer Games and Winter Games), we would need to wait about another 250 years to reach this mark — beyond 2260!

If anyone ever matches or surpasses Phelps' haul, they will most likely come from swimming or gymnastics, where the structure of the competition is more favorable to multiple winners. In fact, 10 of the 17 athletes who have won seven or more gold medals were either gymnasts or swimmers. In team sports such as soccer, one medal per Olympiad is all that is possible, while even in track and field, four medals in a single Olympics is a practical maximum, with Carl Lewis leading the pack with nine gold medals over four Olympics.

Charles Rettner is a research scientist at IBM, where he works on different aspects of chemistry, physics and engineering. His views do not represent those of his employer.

Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

Olympic runner Wayde van Niekerk's gold medal win in the 400 meters last night is an extraordinary feat, and not just because he broke the world record for the event, but because of where he was placed on the track — in one of the very outside lanes, experts say.

In track and field, the middle lanes — lanes 3, 4 and 5 — are the most desirable, while the outside lanes have disadvantages, said Dr. Daniel Vigil, a sports medicine specialist at the University of California, Los Angeles.

The outside lane is undesirable in the 400 meters because the person in that lane can't see his or her competitors. This means that racers often can't pace themselves properly — they don't know if they're going too fast or too slow, Vigil said.

But van Niekerk won, with a world record time of 43.03 seconds, despite being placed in Lane 8, the outermost lane in his race.

"The fact that he overcame that and did as well as he did is truly extraordinary," Vigil told Live Science. "He ran that entire race without ever seeing his competitor... He basically ran in a bubble." [Olympic Form: How Sports Influence Body Shape]

Having a very keen ability to focus and a developed sense of discipline likely played a role in allowing van Niekerk to run at his record-setting pace without seeing his competition, Vigil said.

Running on the inside lane (Lane 1) is also a challenge for sprinting events such as the 200 and 400 meters, Vigil said. That's because, from the inside lane, the curve that people run along is so tight that it's difficult to run forward as fast as you could if you were running in a straight line. "You're fighting forces of gravity and physics," as you try to maintain speed, Vigil said.

Track and field isn't the only sport in which middle lanes are advantageous — they are also desirable in swimming events. That's mainly because, in a body of water like a pool, the "flattest" water (with the least waves) is in the middle of the pool. So simply put, the middle of the pool is faster, Vigil said.

People with the best qualifying times are rewarded by being placed in the middle of the track (for sprinting events) and the pool, Vigil said.

Original article on Live Science.

More than 100 people in Ohio have been sickened with a diarrheal illness linked to swimming in local pools, causing health officials to declare an outbreak in several counties.

Yesterday (Aug. 11), officials at the public health department in Columbus said there has been a recent rise in cases of cryptosporidiosis, an illness caused by a hardy parasite that can survive in chlorinated pools.

Overall, 107 cases of cryptosporidiosis have been reported this year in Columbus, Franklin County and Delaware County, which is more cases than the area has seen in the last three years combined, Columbus officials said.

Although public health officials regularly see cases of cryptosporidiosis, commonly known as "Crypto," "there has been a recent rise over the normal threshold of cases," Columbus Public Health said in a statement.

Officials haven't tied the outbreak to any one swimming location. A number of the people who got sick went swimming multiple times at various recreational water facilities in the three counties, the statement said. [10 Bizarre Diseases You Can Get Outdoors]

The Crypto parasite is protected by an outer shell that allows it to survive in chlorinated water for long periods of time, of 10 days or more, according to the Centers for Disease Control and Prevention (CDC). The main symptom of the illness is watery diarrhea, but the parasite can also cause stomach cramps, vomiting and fever, the CDC said. People become infected with the parasite in swimming pools after swallowing contaminated water.

Cases of Crypto have also been on the rise in the United States as a whole. In the mid-1990s, officials saw less than one case of Crypto per 100,000 people in the U.S., but by 2011, the rate rose to three cases per 100,000 people, according to a 2015 report from the CDC. From 2011 to 2012, there were more than 17,000 reported cases of Crypto in the United States, the report said.

Rates of Crypto are particularly high in the Midwest. In 2011, there were six cases of Crypto per 100,000 people in the Midwest, the CDC report said.

To prevent the spread of Crypto and other illnesses linked with swimming, the CDC recommended that people not swim if they have diarrhea, and stay out of the pool for two weeks after their diarrhea stops if they were diagnosed with Crypto. People should also shower before swimming, take their children on frequent bathroom breaks when swimming, change diapers in the bathroom rather than by the pool and avoid swallowing pool water, the CDC said.

The agency also recommended that swimming water be treated with ultraviolet light or ozone to inactivate Crypto at pools where people may have contracted the disease.

Original article on Live Science.