Is sleep disturbed by vigorous late-night exercise?

Purpose: This experiment examined the influence of prolonged. vigorous late -night exercise on sleep. Methods: Sixteen highly fit male cyclists complet ed each of two 60-h laboratory treatments involving a baseline night, an ex perimental treatment night, and a recovery night. In counterbalanced order, subjects 1) cycled for 3 h at 65-75% of heart rate reserve combined with b right light exposure (3000 lux) light, and 2) were exposed to a 3 h pulse o f bright light (3000 lux) alone. Results: On the baseline and recovery nigh ts, subjects maintained their usual sleep-wake schedules. On the treatment night, exercise + bright Light or bright light alone were centered at 6 h b efore their usual wake times, followed by bedtimes 30 min after the treatme nts, Illumination was 3000 lux during the experimental treatments, 0 lux du ring the sleep periods. and 50 lux at other times. Sleep was assessed with an Actillume (Ambulatory Monitoring, Inc., Ardsley, NY) wrist monitor to de fine sleep onset latency (SOLI, wakefulness after sleep onset (WASO), and t otal sleep time. Subjective assessments of SOL, WASO, and insomnia were als o gathered each morning. No significant differences in objective or subject ive sleep variables were found between treatments. Conclusions: These data are inconsistent with the general opinion that vigorous exercise shortly be fore bedtime disturbs sleep,