Regular Exercise Reduces COVID-19 Risk, Severity, Studies Say

Staten Island Advance, N.Y.

Regular moderate exercise significantly reduces the risk of getting COVID-19, a large international research review has found.

And, for those who do get COVID, routine exercise dramatically lowers the odd of serious illness, hospitalization and death, according the review of several international studies, published on Monday in the British Journal of Sports Medicine.

"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," author Antonio Garcia-Hermoso told Health Day. Garcia-Hermoso is a senior researcher with Navarrabiomed and the Universidad Pública de Navarra in Pamplona, Spain.

The research supports the advice of the Centers for Disease Control and Prevention (CDC), which states on its website that those who do not exercise regularly are more likely to get very ill if they contract COVID-19.

The link between exercise and reduced COVID risk follows a research effort into the findings of 16 studies conducted around the world between 2019 and 2022. In total, they included more than 1.8 million men and women (average age: 53), Health Day reported. Most of the studies were conducted in the United Kingdom, Canada, South Korea, Iran, Spain, Brazil, Palestine, South Africa and Sweden.

In the studies, researchers noted that participants who reported being routinely active were on average 11% less likely than inactive participants to become infected with 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, the studies found.

Researchers found that 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.

Researchers noted that the studies they reviewed differed in their methods and were all conducted before the emergence of the highly contagious Omicron variants that are now common.

Yet, the researchers stressed that 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 told Health Day that 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, Dr. Armeen Poor, an attending physician in pulmonary critical care medicine at Metropolitan Hospital Center in Manhattan, told Health Day.

"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."

Poor also pointed out 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.

He also noted that people who exercise regularly may practice other healthier habits that are likely protective, which could be affecting the outcomes in the 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.