Research Provides Hints About Why Exercise May Help Protect Against COVID-19 Complications

There’s evidence that a specific enzyme our bodies produce during exercise may be protective against lung damage known to play a role in COVID-19 outcomes.

By Philippa GarsonMedically Reviewed by Justin Laube, MD

Last Updated: May 1, 2020

This research sheds light on how exercise may help protect our bodies against myriad diseases and illnesses, potentially including the infection caused by the novel coronavirus.

Research shows that an antioxidant enzyme we produce when exercising may stave off or lessen the risk of acute respiratory distress syndrome (ARDS), a condition that occurs when the lungs become so inflamed they get stiff and swollen, leading to fluid buildup and oxygen deprivation. ARDS is one of the complications that people with COVID-19 can develop, and it is associated with a higher death rate from the disease.

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Many studies have found that the antioxidant extracellular superoxide dismutase (EcSOD) helps protect against ARDS and other heart and lung diseases, according to a review published in May 2020 in the journal Redox Biology. And that protective effect may include helping prevent the severe complications occurring as a result of COVID-19, the article notes.

Zhen Yan, PhD, professor of cardiovascular medicine at the University of Virginia School of Medicine in Charlottesville and the lead author of the paper, says that while it’s important to point out that evidence has not yet included people with COVID-19 (because the disease is too new), the data has implications for people with it and those at risk.

“If you exercise regularly, you will have more EcSOD and better ability to deal with any stressors,” Dr. Yan says. The research suggests that EcSOD is one of the ways exercise may protect people with COVID-19 against more severe complications, like ARDS.

According to information from the Centers for Disease Control and Prevention (CDC), studies that included more than 40,000 people in China who had COVID-19 showed that overall 3 to 17 percent developed ARDS; between 20 and 42 percent of all hospitalized patients developed the complication; and 68 to 85 percent of all patients admitted to ICU developed it. (Deaths from patients admitted to the ICU ranged from 39 to 72 percent.)

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Why Is EcSOD So Good for Us and How Does It Protect Heart and Lung Functioning?

Although our muscles naturally produce EcSOD, they produce it in higher quantities during vigorous exercise. After it is produced in the skeletal muscles, it then spreads through the blood to other organs, such as the lungs, heart, and kidneys.

It’s a potent enzyme, Yan says. And it’s unique because, so far, it is the only known antioxidant enzyme that naturally works in the fluid, noncellular part of blood known as plasma, and it breaks down toxic free radicals produced during disease processes. (Free radicals are harmful molecules our bodies produce. Usually, our own antioxidants are able to neutralize them before they do damage, but when our bodies are burdened with disease or illness, we’re less able to fight them off. We experience what's termed oxidative stress, leaving us more vulnerable to disease.)

Research from Yan’s and other labs (conducted mostly in animals) has found that exercise indeed raises EcSOD levels, which was associated with better lung, heart, and kidney health. Yan’s team has used genetic engineering to get mouse skeletal muscle to produce more EcSOD to mimic the effects of aerobic exercise training. He found that the mice were protected from severe ARDS when injected with a bacterial toxin that would usually cause high death rates.

More research is needed to determine if this protective effect against ARDS happens in people, too — and more specifically in people with infections, like the one caused by the new coronavirus, Yan says.