Physical Activity May Change Your Heart As You Age (In a Good Way)
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People who increase their physical activity may experience beneficial changes in their heart's structure, and these changes could reduce the risk of heart failure, a new study suggests.

In the study, researchers analyzed information from more than 2,700 people who'd had their heart examined with an MRI at the start of the study, and again 10 years later. The participants — who were around 60 years old, on average, at the start of the study — also completed a survey about their physical activity levels during a typical week.

The researchers then looked at how people's heart structures changed over time and whether this was linked with the individuals' activity levels. Often, as people age, the walls of their hearts get thicker, while their heart cavities get smaller. This "small, thick heart" increases the risk of heart failure, a condition in which the heart muscle can't pump enough blood to meet the body's normal demands, said Dr. Roberta Florido, a research fellow in cardiology at Johns Hopkins University School of Medicine in Baltimore.  [8 Tips for Healthy Aging]

In particular, a small, thick heart increases the risk of so-called "heart failure with preserved ejection fraction," Florido said. This means heart failure develops because the heart is stiff, despite having a normal pump function, she said.

The researchers found that, after taking into account participants' activity levels at the start of the study, greater increases in physical activity over the 10-year study period were linked with beneficial changes in the heart's structure. The alterations included a slight increase in heart volume, as well as maintenance of the heart wall's thickness — in other words, the heart's walls didn't get any thicker. These changes could prevent the development of the "small, thick heart" that's associated with heart failure, Florido said.

"We see favorable changes in their heart structure" linked with physical activity, Florido told Live Science. Previous studies have found that physical activity reduces the risk of heart failure, and the new study suggests that these beneficial changes comprise "one of the mechanisms of how physical activity prevents heart failure," Florido said.

Heart failure is on the rise in the United States, and around 6.5 million U.S. adults now live with the disease, according to the American Heart Association. It's estimated that about 50 percent of people with heart failure will die within five years of the diagnosis, Florido said. What's more, there are really no treatments for heart failure with preserved ejection fraction, which makes prevention of this type of heart failure particularly important, she said.

"We need to reinforce the importance of the recommended levels of physical activity, especially with the growth of heart failure [diagnoses] and the lack of treatment strategies for heart failure with persevered ejection fraction," Florido said.

The new study's methods make it difficult to estimate what level of change in physical activity is linked with the beneficial heart changes. That's because the researchers took into account people's activity at the start of the study, meaning that people who performed a lot of physical activity at the start of the study could still see benefits even if they decreased their activity later, Florido said. But in general, the more activity people did, both at the start of the study and over time, the better it was for their hearts, Florido said. A follow-up study will look more specifically at the level of change in physical activity that's needed for these beneficial heart changes, she said.

Florido recommends that people try to meet the U.S. physical-activity guidelines of 150 minutes of moderate activity, or 75 minutes of vigorous activity, per week.

The new findings were presented this month at the American Heart Association's Scientific Sessions meeting in Anaheim, California.

Original article on Live Science.