Alan West, Bloubergrand
Just an observation, for what it is worth.
Watching people exercising, especially runners, wearing face masks and then stopping, gasping for breath, I find it quite strange that they don’t realise that breathing in your own “exhaust gases”, carbon dioxide still trapped in the mask, is depriving your body of oxygen, leading to shortness of breath, tiredness and headache.
Perhaps someone in the medical profession would care to comment.
Keertan Dheda, professor of medicine, director, the Centre for Lung Infection and Immunity, responds:
A mask is safe when walking or running. It does not cause oxygen deficiency.
Studies have shown that after an hour of moderate exercise, blood-oxygen levels are the same, carbon dioxide levels are very slightly higher (less than 5% higher than normal) but quickly settle when stopping exercise or removing the mask.
Of course there is less air inhaled (in terms of the total volume for the same effort) so exercise can feel a little more difficult, but less so if you are fit.
The body adapts over time, but it’s like having an extra workout
Studies show that after an hour one actually compensates by taking larger breaths. In fact, wearing a mask is a form of training some athletes used in the past.
There is also no danger of carbon dioxide toxicity.
Although levels can rise very little, there is no health downside, and it can be blown off very quickly.
Thus exercising with a mask is safe and no need to worry.