Prevention is better than cure!
There is simple strategy that the other answers seem to have overlooked.
Research shows that you can reduce water-loss by exhalation simply by breathing through your nose rather than through your mouth.
According to this paper, the savings are in the region of 40%.
Nasal breathing will also help prevent over-exertion, which ...
I had a quick look at this from another angle in 2021. I found an existing breadth condensate collection device. Not the ideal answer in and of itself, but certainly worth a look.
They place an upper bound for collection from an adult of 250 microlitres a minute, that's if you can actively cool the collection tube. The device collects up to 10 minutes worth ...