Do masks affect exercise?

By Adam Toffan, M.Sc, NSCA-CSCS, CSEP-CEP,
Assistant Fitness Training and Assessment Coordinator, UM Recreation Services

---

Aside from potential discomfort, does wearing a mask affect our exercise? That is the question I want to cover this week — and recent studies are shedding more light on the subject.

Wearing a mask is a recommended way to reduce the spread of COVID-19.

Studies show that medical-grade masks and unvented N95 masks reduce aerosol particle emission from the wearer by 90 and 74 percent, respectively. (The efficacy of cloth masks was less clear.) Data from the American Society for Microbiology shows that cotton, surgical, and N95 masks protect against droplet spread, with higher protection when masks were worn by virus spreaders. As expected, N95 and other respirator masks were most effective, but cloth face coverings did have some benefit. Since mask use became mandated (including donning a mask while exercising in gyms), some people have raised concerns of potential health risks, including breathing in previously exhaled carbon dioxide leading to high blood CO2 levels and reduced oxygen intake. 

The World Health Organization had previously warned that wearing a mask while exercising may reduce the ability to breathe comfortably, especially when the mask becomes wet.

The Centres for Disease Control and Prevention (CDC) suggest that masks should always be worn in public settings. Gyms are also at higher risk than other public settings because respiratory droplets may be propelled further with heavy breathing during vigorous exercise. If you have trouble breathing during intense exercise, the CDC recommends choosing a location with greater ventilation and air exchange (i.e. outdoors vs. indoors). If that is not an option, you may need to find lower-intensity alternatives. People should also change masks when they become wet from sweat. Replacing a wet mask will allow you to breathe more comfortably and prevent the growth of micro-organisms on your mask. 

New evidence appears to demonstrate that masks do not cause some of the more serious adverse effects.

Including hypercapnia (high blood carbon dioxide) and hypoxia (low blood oxygen levels). Recent research shows wearing a mask also has no significant effect on exercise performance. Studies have concluded that intense exercise with a surgical mask or N95 respirator had no detrimental effects on performance (time to exhaustion) and minimal impact on blood and muscle oxygenation. Two studies conducted in healthy adults found that while exercise in a regular mask is generally safe, it does appear riskier to exercise in a very tight, fitted mask, like an N95. It is important to note that people will react to exercise while wearing a face-covering differently. A very active older person may be able to sustain an hour of running in a mask, while a younger person with asthma may not be able to tolerate wearing one at all, even at rest. Because these studies were conducted in healthy and physically active adults, we do not yet know if there would be a different impact on older people, people with pre-existing conditions, or deconditioned to regular exercise. 

As masks remain mandatory in fitness facilities, most people can exercise worry-free.

Exercising with a mask is generally safe for most people, and there are no negative effects on exercise performance. Aside from the discomfort of breathing warm air, proper mask use and replacing wet masks should allow you to exercise effectively and safely, barring pre-existing conditions that may affect your ability to exercise in a mask. If you do find executing your usual workouts while wearing a mask, you may need to alter your program. If you need some suggestions on alternatives, don’t hesitate to ask a fitness attendant.

Sources

---

Asadi, S., Cappa, C.D., Barreda, S. et al. (2020). “Efficacy of masks and face coverings in controlling outward aerosol particle emission from expiratory activities.” Scientific Reports. Vol. 10. 

Epstein, D., et al. (2020). “Return to training in the COVID-19 era: The physiological effects of face masks during exercise”. Scandinavian Journal of Medicine and Science in Sports. Vol. 31(1). Pp. 70-75.

Shaw, K., Butcher, S., Ko, J., Zello, G.A., Chilibeck, P.D. (2020). “Wearing of Cloth or Disposable Surgical Face Masks has no Effect on Vigorous Exercise Performance in Healthy Individuals.” International Journal of Environmental Research and Public Health. Vol. 17(21).