What happens when you exercise with a face mask on?

Masks make it harder to inhale the quantity and quality of air needed to perform at the highest levels. Exercising leads to faster and bigger breaths, so wearing a mask during exercise places a further strain on airflow.

When you work out hard, your muscles produce lactic acid, which causes that burning sensation. It is then converted to carbon dioxide and exhaled, but what happens when the carbon dioxide is trapped by the mask? As you move from more moderate to heavy exercise, you may be rebreathing carbon dioxide, which can reduce cognitive function and increase breathing rate.

There may also be less oxygen in the recycled air, which could imitate exercising at higher altitudes. So it is important we gain a better understanding of the limitations of heavy exercise with a facemask.

Experts Weigh-in

The World Health Organization (WHO) says people shouldn't wear masks while exercising because they may reduce one's ability to breathe comfortably.

"Sweat can make the mask become wet more quickly, which makes it difficult to breathe and promotes the growth of microorganisms," the WHO's guidance reads.

However, many experts say that if you'd prefer to keep your mask on the whole time while you work out, that there's no real danger, though it might not be comfortable at first. This statement may sound contradictory but it's all very subjective. Many factors are mostly related to individual needs and health.

In conclusion, if you chose (or are forced) to wear a mask while exercising then the silver lining is that your lungs and cardiovascular system will get an extra workout because it is providing extra breathing resistance. The more you exercise with a face mask on, the more accustomed your body will become to the reduced flow of oxygen, and theoretically, should improve your endurance.