Effect of Night Exercise during 27-Hr. Total Sleep Deprivation on the Subsequent Sleep

Abstract

This study was designed to determine the effects from loading and nonloading of night physical exercise during 27-hr. total sleep deprivation on the subsequent sleep. Subjects were 6 healthy male students. They cycled on the bicycle ergometer at 50% of VO₂ max for 10 min., and then rested for 20 min.; repeated this schedule 14 times during the night (00:00 to 08:00). The standard polysomnograms were recorded during day sleep after exercise and during the following recovery-night sleep. When night exercise was not imposed, the sleep recordings were made during the day sleep (day sleep after no exercise), after the 27-hr. total sleep deprivation and following recovery night sleep. Stage 3 and Stage 4 sleep latencies were significantly shortened in the exercise condition as compared with those on baseline night and the no-exercise condition. The mean amount of slow-wave sleep was in the order of baseline < no exercise < exercise, each increase being significant. Stage 2 sleep, however, significantly decreased. The rectal temperature during sleep was significantly higher in the early half of day sleep after exercise than in that without exercise. The self-rating of the sleep depth and rapidness of sleep onset were only significantly better for both conditions compared with that for baseline night. There were no significant differences on any sleep parameters between the exercise conditions after recovery sleep. Results suggest that the increase in slow-wave sleep during day sleep after night exercise may be ascribed to the effects of both the exercise and the total sleep deprivation. The results support the hypothesis that increase in slow-wave sleep was part of recovery from fatigue.