First, physical activity has the potential to reduce the severity of COVID-19 infections. This is related to what happens in the lungs during an infection. The immune system detects the virus invader in the lungs and attacks it. The conflict between the virus and immune cells creates inflammation. That inflammation causes damage to lung tissue that interferes with breathing and can become severe enough to require medical interventions, such as mechanical ventilators.
How is this relevant to physical activity? When you are active, muscles produce compounds that improve functioning of the immune system and reduce inflammation. Thus, physical activity strengthens the two biological processes that react to the infection.
Second, physical activity is effective for both preventing and treating heart diseases, diabetes and eight cancers, all of which increase the risk of severe illness and death among those infected with the coronavirus. Though physical activity is widely recommended by health authorities, efforts to promote active lifestyles are minimal. It makes sense now to encourage people, especially those with chronic conditions, to be moderately active prior to being infected, to reduce severity of illness after infection.
Third, symptoms of stress will increase as the pandemic continues, due to health threats, job loss, reduced income and isolation. Fortunately, being physically active has important mental health benefits and encouraging people to be active could help many cope with ongoing stress and avoid psychological ill-health. Each session of physical activity reduces symptoms of depression and anxiety, so being active every day can be a partial antidote to the stress of the pandemic.
Fourth, the body’s response to psychological stress creates imbalances between cortisol and other hormones that negatively affect the immune system and inflammation. Thus, psychological stress affects the underlying biological processes of COVID-19 but restoring cortisol balance is another mechanism by which physical activity benefits immunity and inflammation. The most effective strategies for improving cortisol balance are physical activity and stress management. Because older people have disrupted cortisol physiology and weaker immune systems, physical activity may be particularly important for this large population at high risk for COVID-19.
Today, we share a contribution from:
Dr. Jim Sallis, Health Psychologies, University of California at San Diego
Dr. Michael Pratt, Preventative Medicine Physician, University of California at San Diego