It's now common knowledge that to protect yourself from the novel coronavirus, you should stay home, keep at least six feet between you and non-family members when you must go out, wash your hands, and disinfect high-touch surfaces frequently.
But a researcher at the University of Virginia School of Medicine is proposing another key behavior is added to the list: exercise — and not just for its benefits to the lungs, immune system, and mood.
In a new review of past research, Zhen Yan, a professor of cardiovascular medicine who runs a molecular exercise physiology lab at UVA, showed that exercise boosts the production of an antioxidant known as "extracellular superoxide dismutase," or EcSOD, which in turn, protects against acute lung disease and other diseases.
In particular, Yan said, the antioxidant can protect against acute respiratory distress syndrome, or ARDS, which is deadly in 45% of cases. ARDS affects up to 85% of patients in the ICU affected by COVID-19, the illness caused by the coronavirus.
Yan said the takeaway is that exercise (while keeping a safe distance from others) is a key strategy to protect against severe complications from COVID-19, should you fall ill.
"We cannot live in isolation forever," he said in a press release. "Regular exercise has far more health benefits than we know. The protection against this severe respiratory disease condition is just one of the many examples."
The review included past animal and human research, but not coronavirus patients
Yan and a colleague looked at 120 past studies, many of them conducted in animals and some of them from his own lab, to see how, on a molecular level, exercise-prompted EcSOD protects tissues from oxidative stress, which contributes to the development of many diseases.
The pair was especially interested in the benefits of skeletal muscle EcSOD, which is produced naturally but boosted with cardiovascular exercise. Exercise can also help the antioxidant circulate through the body to other tissues affected by disease.
Yan said their findings "strongly support" the possibility that exercise can prevent or at least reduce the severity of ARDS. Even a single session, the press release said, can spur production of the antioxidant.
Yan told Business Insider that while aerobic exercise is best at stimulating EcSOD, weight-training is important too since "more muscle will likely lead to more EcSOD production, hence more benefits."
He recommended at least 30 minutes each day to reap the benefits — if you haven't been infected with COVID-19 yet. Those who are infected should try to move moderately, he said, since long-term bed rest can also exacerbate lung infection and cause other complications.
The review should be looked at cautiously because it only looked at past research, not necessarily in humans, and didn't compare ARDS outcomes among COVID-19 patients who exercise versus those who don't, Helen Kollias, director of science at Precision Nutrition, told Business Insider.
Plus, how EcSOD and antioxidants affect disease and inflammation has been "debated for decades," Dr. Craig Weinert, a pulmonologist and critical-care physician at the University of Minnesota, told Business Insider.
"I'd say that there is little evidence to support exercise as a preventive factor in the development or resolution in ARDS," he said.
Exercise remains an important way to boost your immune system and keep your lung function healthy
Regardless of its effects on coronavirus patients, it's clear that staying active can keep your lungs and immune system healthy, which is especially important during the pandemic.
Just make sure you take a measured approach to your exercise in order to hit that immune-boosting sweet spot, Dr. Jebidiah Ballard, an emergency medicine physician, previously told Insider.
"Use common sense and assess how your workout makes you feel after," he said. "Are you more energized or do you feel wiped out? This is probably not the time to train for a personal best on a 10K."
Manage your expectations, too, Kollias said. While physical activity is associated with a reduced risk of many chronic conditions known to worsen COVID-19, "you can't exercise for a week and expect to see any reversal of any disease," she said. "It would take weeks to see any improvement."
She recommends people with underlying conditions, just like those who are healthy, exercise in a safe environment in order to improve their mental and physical health.
"Would it improve their chances if they get COVID-19? Not in a day or week, but if they can improve their overall health over weeks, then very likely," she said. "There is no magic mechanism that makes exercise work uniquely to this virus. It's the overall effect that moderate exercise has on health."
