Acute physical exercise under hypoxia improves sleep, mood and reaction time

Area of Science:

• Exercise Physiology
• Sleep Science
• Altitude Medicine

Background:

• Hypoxia, simulating high altitude (4500 m), negatively impacts sleep, mood, and reaction time.
• The effects of acute physical exercise under hypoxic conditions on these parameters require further investigation.

Purpose of the Study:

• To evaluate the impact of two exercise sessions at 50% VO2peak under hypoxia on sleep, mood, and reaction time.
• To compare these effects against normoxic conditions and exercise in normoxia.

Main Methods:

• Forty healthy men were randomized into four groups: Normoxia (NG), Hypoxia (HG), Exercise in Normoxia (ENG), and Exercise in Hypoxia (EHG).
• Participants underwent 28 hours of hypoxia exposure with two 60-minute exercise sessions at 50% VO2peak on days 1 and 2.
• Sleep, mood, and reaction time were assessed at various time points, including 40 minutes post-awakening and 28 hours after hypoxia initiation.

Main Results:

• Hypoxia exposure alone impaired sleep efficiency, increased wake after sleep onset, and negatively affected mood and reaction time.
• Exercise under hypoxia significantly improved sleep efficiency, N3 sleep, REM sleep, and reduced wake after sleep onset.
• Exercise in hypoxia also led to improvements in tension, anger, depressed mood, vigor, and reaction time compared to hypoxia alone.

Conclusions:

• Acute physical exercise at 50% VO2peak under hypoxic conditions can mitigate the detrimental effects of high altitude on sleep.
• This exercise intervention appears to reverse negative impacts on sleep efficiency and quality, potentially improving mood and reaction time.
• Exercise in hypoxia offers a promising strategy to counteract physiological disturbances associated with altitude exposure.