Looking for a new reason to work out?
Here's a good one: Regular exercise appears to significantly reduce your risk of getting COVID-19, a large international research review has found.
And, if you do get COVID, the study found, routine moderate and/or intense exercise dramatically lowers your odds for serious illness, hospitalization and/or death.
"There is evidence that regular physical activity might contribute to a more effective immune response, providing enhanced protective immunity to infections, which could explain the relationship between exercise consistency with COVID-19 infection," said study author Antonio Garcia-Hermoso. He's a senior researcher with Navarrabiomed and the Universidad Pública de Navarra in Pamplona, Spain.
The apparent link between regular activity and reduced COVID risk follows a deep dive into the findings of 16 studies conducted around the world between 2019 and 2022. In all, they included more than 1.8 million men and women (average age: 53). Most were conducted in the United Kingdom, Canada, South Korea, Iran, Spain, Brazil, Palestine, South Africa and Sweden.
Researchers observed that participants who reported being routinely active were (on average) 11% less likely than inactive participants to become infected with SARS-CoV-2, the virus that causes COVID.
And among those who did get sick, regular activity was linked to a 36% lower risk of hospitalization. Routine exercise was also associated with a 34% lower risk of severe illness, and a 43% lower risk of dying.
As for just how much of a workout brought the biggest benefit, researchers found that roughly 2 hours and 20 minutes of moderately intense exercise each week -- or 1 hour and 15 minutes of vigorous exercise -- offered the broadest protection against the virus.
The researchers offered their findings with a note of caution: The studies they reviewed differed in how they were done. None tested the potential of trying out different exercise regimens, relying instead on observations from participants' usual habits. Also, the studies were all conducted before the emergence of the highly contagious Omicron variants that are now common.
Still, researchers noted, exercise is likely helpful for several reasons. They pointed to exercise's ability to reduce inflammation and stress, while boosting heart health and immunity. In addition, Garcia-Hermoso said, routine activity can also reduce known "risk factors for a worse prognosis of COVID-19, such as obesity or high blood pressure."
For all those reasons, the findings make a lot of sense, said Dr. Armeen Poor, an attending physician in pulmonary critical care medicine at Metropolitan Hospital Center in New York City.
"We know that regular exercise has a wide array of benefits that can be protective in countless ways, including but not limited to neurologic, cardiovascular, respiratory, digestive and psychiatric wellness," said Poor, who reviewed the findings.
"And with this benefit, people who exercise regularly will definitely reduce their chances of being in the higher risk categories that we know are more likely to have adverse outcomes from severe COVID-19," he added.
Poor also noted the "strong connection between regular exercise and obesity," with obesity putting patients at increased risk for worse COVID-19 outcomes.
"Adipose tissue -- or fat -- has inflammatory properties, and so reducing that with regular exercise can go a long way in helping people feel better and prevent significant disease," he said.
Poor pointed out that people who exercise regularly "may also have healthier backgrounds and practice other healthier habits that are likely protective, which could be affecting the outcomes in this data."
Yet overall, he said, the conclusions might be expected.
"It shouldn't be a surprise to us that routine physical activity can help us feel and live better," Poor said.
The findings were published Aug. 22 in the British Journal of Sports Medicine.
There's more about physical activity and COVID-19 at the U.S. Centers for Disease Control and Prevention.
SOURCES: Antonio Garcia-Hermoso, PhD, senior researcher, Navarrabiomed, Universidad Pública de Navarra, Pamplona, Spain; Armeen Poor, MD, assistant professor, medicine, New York Medical College, and attending physician, pulmonary critical care, Metropolitan Hospital Center, New York City; British Journal of Sports Medicine, Aug. 22, 2022