Its physical and mental health benefits are well documented, but does running increase testosterone levels?
Higher testosterone levels are associated with a plethora of health benefits including boosted bone density, increased muscle growth and improved mood, so it’s easy to see why people might want more of the hormone. Weightlifting is usually touted as the best way to boost your testosterone levels – but could hopping on one of the best treadmills have the same effect?
To answer this, it’s important to first understand what testosterone is and the many impacts this hormone has on the body.
We’ve spoken to two medical professionals – Dr Noel Young, Clinical Innovation Associate at Thriva and Hussain Abdeh, clinical director and superintendent pharmacist at Medicine Direct – to find out more about the impact running can have on testosterone levels.
- Read more: How running changes your body
What is testosterone?
It’s probably a word you’ve heard many times before, but what is testosterone?
“Testosterone is a steroid hormone responsible for the development of what’s called secondary sexual characteristics, or changes that occur during puberty,” says Dr Young.
“For males it causes your larynx to thicken and your voice to deepen, facial and pubic hair growth, and development of the penis and testes.”
Crucially, for those interested in the link between testosterone levels and athletic performance, it also helps build muscle and bone strength, as well as driving libido and the production of sperm.
“It is often called the male sex hormone, and is made by the testes,” Dr Young says. However, he adds, "it is also present at lower levels in women, where it's made by the adrenal gland and ovaries.”
“In women, it’s responsible for libido and arousal, and also plays a role in developing muscle and bone strength.”
Benefits and drawbacks of higher testosterone levels
Higher testosterone levels have been associated with boosted bone density, increased muscle growth and improved mood. “It’s tempting to think that more must be better, but that is not the case,” says Dr Young.
“Having too much testosterone can lead to issues such as skin and hair problems, and prostate enlargement. It can lead to reduced fertility, poorer heart health due to weight gain, higher cholesterol and blood pressure.”
Instead, he suggests it’s important to maintain healthy levels of testosterone, as both lower and higher levels are associated with ill effects.
“When your testosterone levels are optimal, it's associated with better energy, heart health, mood, memory, libido as well as stronger bones and a leaner body mass,” he says.
A 2010 review published in Sports Medicine, exploring testosterone physiology in resistance exercise training, delved into the positive impacts the hormone can have on muscle growth.
It found: “Testosterone is one of the most potent naturally secreted androgenic-anabolic hormones, and its biological effects include promotion of muscle growth. In muscle, testosterone stimulates protein synthesis and inhibits protein degradation; combined, these effects account for the promotion of muscle hypertrophy by testosterone.”
And while higher testosterone levels have thus been shown to benefit those looking to achieve muscular hypertrophy, they can also positively impact the skeletal system.
“Testosterone is important for bone density, which decreases with age in men,” explains Abdeh. “Aging makes your bones weaker and increases the risk of osteoporosis. Higher levels of testosterone reduces this risk.’
Does running increase testosterone?
“Running could have an impact on testosterone, but it depends on the intensity at which you run,” Dr Young explaining. “Evidence suggests that running at higher intensity, like sprinting, is what is needed for a boost in testosterone. You would have to run at 90% of your maximal oxygen uptake (a way of measuring intensity) to see this effect."
The good news is that you only need 90 seconds of running at this speed to achieve a boost in testosterone, according to Healthline.
“The mechanism for this is thought to be due to the body’s response to exercise, where it releases a variety of hormones that break down energy stores (like adrenaline and cortisol) and help build and repair muscles (like testosterone).”
But, he warns, running for longer time periods actually can lead to reductions in testosterone levels.
“This is because of the effects of cortisol. Cortisol is a stress hormone, and has a see-saw-like relationship with testosterone. As cortisol production goes up, testosterone goes down and vice versa. Prolonged exercise can lead to increases in cortisol and drops in testosterone.”
“Running puts pressure on the body, which can impact the endocrine system,” Abdeh expands. “The endocrine system is responsible for producing and secreting all bodily hormones and is very sensitive to stress. Parts involved with reproduction, such as testosterone, are particularly sensitive.”
“The reason for this is that, when your body is under stress, the functions that are essential to survival are put first. Because reproduction is not vital for your survival, the production of testosterone is prioritized rather low down by your endocrine system.”
Nevertheless, the decrease in testosterone caused by running is not normally significant enough to create any significant health problems.
- Read more: What muscles are used for running
Best exercise for increasing testosterone levels
Anyone looking for a testosterone-boosting physical activity should turn to resistance training methods such as bodybuilding and weightlifting, research shows.
One study published in the European Journal of Applied Physiology found that: “In general, testosterone concentration is elevated directly following heavy resistance exercise in men.” However, testosterone response to resistance exercise in women was deemed “equivocal”.
“Resistance training, or strength and weight training, are especially good for boosting testosterone levels,” Dr Young says. “This effect is seen as more muscle mass is activated. So doing squats over bicep curls, or using free weights over machine exercises, will be better as both involve larger muscle groups such as your core, back and thighs.”
“Exercising to exhaustion, however, leads to a drop in testosterone so it’s important not to overstretch yourself and allow sufficient time for recovery in between exercise sessions.”
Other factors that can increase testosterone production
As mentioned earlier, stress and consequent cortisol production can lower testosterone levels. So, by managing stress levels, you can mitigate this impact.
Dr Young suggests the use of methods such as mindfulness and deep breathing to reduce stress levels. He also says practicing good “sleep hygiene” can have a positive effect on stress levels.
“Getting too little sleep can increase stress hormones in your body, which lowers testosterone,” he says. One study published in Sleep Science showed that levels can reduce by 10 to 15 percent after reducing sleeping time to five hours for five days. Aim for between seven to nine hours of good quality sleep.
There are also dietary factors you can focus on, to ensure your testosterone levels don’t drop.
“Ensure you get enough magnesium and zinc in your diet,” advises Dr Young. “Zinc is involved in the production of testosterone, and deficiencies have been linked to low testosterone states. Low magnesium is also associated with low testosterone, though the exact role it plays in testosterone production is still not clear. Good sources of zinc include pumpkin seeds, spinach and chia seeds, while good sources of magnesium include spinach, kale and beans.”
Jakob L Vingren et al. (2010). Testosterone physiology in resistance exercise and training: the up-stream regulatory elements. Sports Medicine - accessed April 2022.
Camilla Hirotsu et al. (2015). Interactions between sleep, stress, and metabolism: From physiological to pathological conditions. Sleep Science - accessed April 2022.
Rafael Timon Andrada et al. (2007). Variations in urine excretion of steroid hormones after an acute session and after a 4-week programme of strength training. European Journal of Applied Physiology - accessed April 2022.