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Need Another Reason to Exercise? It Could Protect You from COVID-19

3 minute read

Regular physical activity may help protect you from severe COVID-19—and could even keep you from getting infected, according to a research review published Aug. 22 in the British Journal of Sports Medicine.

“It’s time to consider exercise as medicine,” says co-author Yasmin Ezzatvar, a doctor of physical therapy and a nursing instructor at Spain’s University of Valencia. “This is more evidence to really affirm that.”

The researchers analyzed 16 previously published studies that looked for associations between physical activity and COVID-19 outcomes. These studies included more than 1.8 million adults in all, and most relied on participants self-reporting their exercise habits. Most of the studies were conducted in 2020 and early 2021, before COVID-19 vaccines became widely available.

Compared to people who didn’t exercise much, active people were about 36% less likely to be hospitalized and 43% less likely to die if they caught the virus. People who got at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous movement each week—the amount recommended by U.S. public-health officials—had the best protection, the researchers found.

In some ways, that finding is obvious. Exercise is consistently linked to good health and longevity, and it can help prevent or manage chronic conditions that put people at risk of COVID-19 complications, such as diabetes and heart disease.

More surprisingly, active people were also about 11% less likely to get infected compared to those who were more sedentary, the researchers concluded—which suggests that exercise itself may be protective.

Read More: These Apps Pay You in Crypto for Working Out

“Regular physical activity can contribute to a more effective immune response,” Ezzatvar says. “It can provide enhanced immunity to [many] infections, not only COVID.”

The paper does not provide proof that exercise is causing these effects—only that it’s linked to better COVID-19 outcomes. There could be other explanations for the trends, such as differences in lifestyle, viral exposure, and socioeconomic status between active and sedentary people. Most of the included studies were also published well before Omicron became dominant and when most people were not vaccinated, so it’s difficult to generalize the findings to the present.

One other potential caveat: if you happen to be exercising next to someone who already has COVID-19, your workout routine may not save you from getting sick. A small study published in May found that someone doing high-intensity exercise emits about 132 times as many aerosols per minute as they do at rest—which is bad news if your treadmill neighbor happens to have the virus.

Still, exercise is “100%” recommended for most people, Ezzatvar says. “It is good for your health—not only for COVID [protection], but also your mental health and your physical health.”

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Write to Jamie Ducharme at jamie.ducharme@time.com