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.