High-intensity exercise in the evening does not disrupt sleep in endurance runners

This study examined how early evening high- and low-intensity running sessions affect sleep in endurance-trained male runners. Both high-intensity (90% VO2peak) and low-intensity (45% VO2peak) exercise improved total sleep time and reduced wakefulness compared to no exercise, with no significant differences between exercise types. High-intensity exercise slightly increased nocturnal heart rate but did not disrupt sleep quality or efficiency. These results challenge guidelines advising against evening high-intensity workouts, suggesting that such sessions can support recovery and sleep in trained individuals.

Endurance athletes can safely perform high- or low-intensity exercise in the early evening, as both improve sleep duration without adverse effects on quality. To balance recovery, alternate between intensities based on training schedules and consider ending sessions at least 3.5 hours before bedtime. These findings are based on controlled settings in trained males and may not generalize to untrained individuals or other groups.