Should I use a mask for exercise?

With regions re-opening many people are eager to get back to their local gym, park or community centre. As a result, the question of whether one should wear a mask for exercise has gained significant attention.

In some areas, masks are mandatory in all indoor public spaces. And recently, Hong Kong mandated masks to be used outdoors . If there are governmental regulations in your area, those need to be followed. If not, it may be left to local authorities, private businesses or you, yourself, to decide whether to wear a mask.

Do masks work?

A number of factors are involved to determine whether someone gets infected or not, but it’s largely a function of proximity and time. How close you are to another person. And, how long you are with that person.

Because of this is a new virus, there hasn’t been enough time to do robust studies. But masks have been associated with lower infection rates in hospital workers. There is also evidence that outbreaks and symptoms are be less severe when people wear masks. And previous studies have shown surgical and similar masks reduce infections of other viruses.

Given this, masks can act as a barrier reducing transmission of the virus and protecting the user. As a result, national agencies recommend wearing a mask when you can’t be more than six feet apart. However, as most masks aren’t sealed, it is still possible for the virus to exit/enter around the edges. So they’re not foolproof.

Exercising Outdoors

To date, the majority of infections have occurred indoors. Two studies (both in pre-print meaning they have not been peer-reviewed or published) have reported on outdoor transmission. The first found only one of 318 recorded outbreaks to occur outside. The other reported an 18.7 times greater likelihood of transmission indoors compared to outdoors.

The lower infection rate outdoors is probably due to a number of factors. First, ventilation is greater outdoors and therefore the virus is more likely to get spread over a larger area. Second, physical distancing is easier to practice outdoors than indoors. And lastly, sunlight and humidity may cause the coronavirus to deteriorate. Although this last study was done in a lab so it isn’t known if the same thing happens in the real outdoor world.

That of course doesn’t mean there’s no risk of contracting the virus outside. Again, proximity to others and time come into play. However, the risk of infection when passing a walker, runner or cyclist outdoors is considered to be very small. If there is space, giving a wide berth is encouraged. In addition, exercisers should refrain from spitting and clearing nostrils when others are around. If physical distancing isn’t possible, then wearing a mask outside is ideal.

Exercising Indoors

In contrast to outdoors, the risk of infection is far greater indoors. All of the recorded “superspreader” events have happened indoors (restaurants, choir practice, workplace). These events suggest the virus may stay in the air for some time. The additional concern with respect to exercise, is the increased force and frequency of breathing that occurs. This can result in particles carrying the virus to travel further into the room.

In a (pre-print) randomized study of training in a fitness centre or not, only one new case occurred in 1896 people in the training arm and no cases in the non-training arm. This suggests going to a fitness centre may be safe. However, the training centres enforced strict hand washing, physical distancing and regular disinfecting of equipment. The study was also done when positive cases in the surrounding community were low. In addition, it was only two weeks long. Much shorter than many of us hope to exercise.

But more significant outbreaks have occurred in fitness centres, with one in South Korea linked to 112 cases in fitness classes across 12 facilities. Of note, there were no infections in classes with less than five participants, nor in the Pilates/yoga classes. This suggests physical distancing is one of the best defenses. And also lower intense exercise may be different from higher intensity exercise such as aerobic dance classes. Another outbreak has occurred in Calgary linked to 40 cases at a single cycling spin studio.

When indoors, you’re at the mercy of the confined space and the room’s ventilation. This was apparent from a restaurant outbreak in which most cases occurred to people who were downwind of the air conditioner from the initial case. If possible, choose to exercise outdoors (some centres have moved classes outside) or in your own home.

If you do choose to exercise in an indoor public facility, it’s best to use a mask. Particularly in small rooms. In addition, ask about the room’s ventilation system (where is it and how it works), how many people are allowed in the area at once (how close you are to others) and how long you spend in the room. Also, look into how much time is given between groups (the longer the better) and the frequency of equipment cleaning. Lastly, use a facility that collects contact information from all users. That way if there is an outbreak, you’ll be contacted.

Considerations When Exercising with a Mask

For many people, wearing a mask is a new experience that may take some adjustment. There’s been some debate as to whether wearing a mask during exercise is problematic or effects performance (here and here).

Wearing a mask while exercising is unlikely to be harmful. A lab investigation did show airflow is slightly reduced through a surgical mask. And an exercise study of athletes using sealed elevation masks (used to mimic altitude training, not reduce virus transmission) resulted in improvements in some lung measures. This suggests a slightly greater strain of the muscles around the lungs. However, for most people, this effect will likely go unnoticed.

In addition, wearing a mask may make you hotter and result in more sweating. This discomfort may lead to mask touching, which should be avoided. Extended exercise and excessive sweating may reduce a mask’s effectiveness and require it to be replaced for a dry one.

Using a mask, however, should not be viewed as an alternative to physical distancing, hand washing and disinfecting surfaces before and after use. These should all happen together.

Proper Use of a Mask

1. Wash hands.
2. Use loops or ties to place mask over nose and mouth, and secure it.
3. Adjust mask if needed (avoid touching the front).
4. Avoid touching the mask when wearing.
5. Remove using the loops or ties.
6. Fold and dispose of in a clean bag.
7. Replace mask if moist, dirty or damaged.
8. Do not have mask hang off your face.
9. Wash hands.

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