Is masking up during exercise necessary?

Is it wise to wear a mask during exercise? The answer is complex and will differ between people, the type of exercise and environment in which you are exercising. Certainly, mask wearing in public will save lives by decreasing person-to-person transmission of COVID-19, lowering hospitalizations and death, particularly in populated areas where the cases of Coronavirus are rising.  The dramatic decrease in infection rates are shown with different models and simulations by various researchers (and others).  In particular, research shows that wearing a mask in public is most effective at stopping the spread of the virus when compliance is high.

In the area where I live, southeast Wisconsin, USA, our research at Marquette University indicates that only 42% of people were wearing a mask when going into a store in the first week of June, 2020. This 42% is about half of the estimated 80% of what is needed to substantially control the transmission of the coronavirus and reduce mortality by up to 65%.

[Hear Sandra on National Public Radio, (NPR WUWM) in the US providing expert advise on mask wearing during exercise].


Are mask-wearing expectations in public the same when exercising?

Exercise poses an interesting dilemma relevant to the question of mask-wearing.  Because exercising at high intensities results in laboured breathing (to increase oxygen delivery to the working muscles), people close to the person exercising are at high risk of potential infection via respiratory airborne droplets forcefully expelled by the person exercising. While there is minimal definitive research on this aspect of the Coronavirus, a simulation study indicated that the 6-foot rule of physical distancing is not adequate when cycling or running.  Here is a commentary on the study. The bottom line is that the faster you are traveling on foot or on bike, greater physical distancing between people — especially those that trail behind others — is necessary to minimize infection risk.

However, the World Health Organization recommends that people avoid wearing masks during exercise because it may reduce the ability to breathe comfortably. Mask wearing, especially during high-intensity exercise, increases the work of breathing. In fact, research shows that more tight fitting masks during moderate exercise will lead to higher heart rates, higher facial skin temperatures and greater discomfort. Furthermore, wearing a thick mask can also put the exercising person at risk of C02 rebreathing (inspiring high levels of C02), which can lead to lightheadedness, dizziness and even fainting. Lastly, core body temperature increases during exercise causing sweating, and is not comfortable. In general, it’s recommended that a  exercise mask that best balances comfort and protection involves no more than two layers of a breathable cloth without a tight seal around your face.

Here are some factors to consider when deciding to wear a mask during exercise, keeping in mind there is no easy one-size fits all answer.

How intense is the exercise?

High intensity exercise will increase rates of breathing and the distance that respiratory droplets travel. If the exercise is intense you will need to be at distances much further than the typically recommended 6 feet to keep others and yourself safe if you are not wearing a mask.


Are you exercising indoors or outdoors?


Outdoors is more desirable, and physical distancing easier to achieve. However, many indoor gyms are reopening.  Despite physical distancing guidelines, air circulation and ventilation quality, level of crowding, and size of the gym space affect the level of risk.


How many people are around you when exercising?


The greater the number of people exercising around you — even when distanced 6-feet apart — is an important variable. The higher density of people, the greater chance of transmission of the virus — especially if the exercise is intense and others are without masks. Keep distances greater than 6 feet apart.

While there is no straightforward answer as to whether you should wear a mask during exercise, knowing some of these above factors will help you make a wise decision.  If for example you run or walk outdoors and there are few people around, the risk is low for potential transmission to others and vice versa.  If, however, you are indoors with limited circulation and lots of people in the same area (even if 6 feet apart) who are exercising at moderate to high intensities, the risk of spread could be high.  Then of course there is every scenario in between.

Remember that regular exercise protects the immune system especially as we age.  While exercise is important, carefully consider the choice of wearing a mask.