Melatonin and sleep responses to normobaric hypoxia and aerobic physical exercise: A randomized controlled trial.

This work evaluated the effects of moderate physical exercise performed under hypoxic conditions on melatonin and sleep. Forty healthy men were randomized into four groups: Normoxia (N) (n = 10); Hypoxia (H) (n = 10); Exercise under Normoxia (EN) (n = 10); and Exercise under Hypoxia (EH) (n = 10). The observation period for all groups was approximately 36 h, beginning with a first night devoid of any intervention.