After 10 minutes, we removed the face mask but the subject remained in the resting position for another 170 minutes. During the post- exercise phase, the subject remained in the resting pos- ition immobile. Ten minutes of VO2 measurements were started at 30, 60, 90, 120, 150, and 180 minutes post ex- ercise. For each measurement session, average VO2 data during the final 5 minutes was used.