Can exercise provide defense against COVID-19?

Grab your gym clothes and walking shoes because your friend is probably right. While there haven't been many studies on exercise protecting against infections, the few that exist all suggest it does.

The biggest study on this, done by Harvard Medical School, was published in JAMA Network Open in February 2024.

The study tracked almost 62,000 adults aged 45 and above from before the COVID pandemic started in early 2020 until the end of 2022. Researchers gathered information on factors like chronic diseases, income levels, and lifestyle habits that might affect the risk of infection. They also kept an eye on who got COVID-19 and how severe their symptoms were.

Out of all the participants, 69% were considered "sufficiently active," meaning they did moderate to vigorous exercise for at least 150 minutes every week. Another 11% were "insufficiently active," and 20% didn't exercise at all.

The results showed that those who kept up with enough physical activity were 10% less likely to get COVID-19 and 27% less likely to be hospitalized because of the virus compared to those who didn't exercise. This protective effect was especially clear among women. Interestingly, people who exercised a little (but not enough to meet the recommended amount) didn't see much better results than those who didn't exercise at all. These findings suggest that a good amount of physical activity is needed to protect against COVID-19.

The study also emphasized the importance of COVID vaccination, which significantly lowers the risk of infection and hospitalization.

Studies also show that regular exercise helps defend against other illnesses like the flu, as well as conditions such as heart disease, cancer, dementia, and depression

How does regular exercise bring about these health benefits? Scientists are just starting to uncover the answer. Exercise boosts the effectiveness of various types of white blood cells that combat infections. It also triggers the body to produce antibodies in the linings of the nose, throat, airways, and lungs, which help fight infections. Moreover, regular exercise helps regulate the immune system, preventing it from overreacting during infections and causing harm not only to the invading germ but also to the body itself.

As you've likely read here before: no medication ever created provides as much protection for your health as regular exercise does.

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