Have you heard the claims that strenuous exercise can suppress the immune system and increase infection risk, particularly when conducted over long periods? A lot of fitness professionals have. An international group of researchers analyzed that assessment in a debate article in Exercise Immunology Review (2020; 26, 8–22). James Turner, PhD, and John Campbell, PhD, exercise physiologists from the University of Bath in England, are leading opponents of the hypothesis and maintain that exercise is beneficial for immune function.

A research review does show that those who exercise at levels far above health recommendations—for example, high-performance athletes and elite military groups—experience a greater risk of infection along with alterations to immune biomarkers. However, Campbell and Turner note that these changes are strongly influenced by nonexercise factors like genetics, nutritional status, stress, sleep disruption and more. Researchers both for and against the hypothesis that arduous exercise can suppress the immune system agree that infection susceptibility is multifactorial.

Turner and Campbell urge people not to fear that exercise will suppress the immune system, placing them at increased risk of coronavirus. Instead, the researchers encourage people to stay fit and physically active while following government guidelines for health and safety.

See also: Resistance Training Tips to Minimize Infection Risks