Limitations
desaturation
Our results are limited to short-term face mask use, acute exposure to 3000-m altitude, resting to moderate exercise conditions (only rest for cognitive tests, only exercise for TAlthough the sample size was enough to detect main predictable cardiorespiratory changes, it was not large enough to provide enough power for more subtle or heterogeneous changes in other parameters, in particular those regarding cognitive function. Even if a larger sample size had revealed a statistical significance of the mask-induced desaturation during exercise in HH, its magnitude would have remained below the commonly accepted clinically significant threshold of −4 percentage points.