Background: This study sought to determine the 12-month effects of exercise increases on objective and subjective sleep quality in initially inactive older persons with mild to moderate sleep complaints.
Methods: A nonclinical sample of underactive adults 55 years old or older (n=66) with mild to moderate chronic sleep complaints were randomly assigned to a 12-month program of primarily moderate-intensity endurance exercise (n=36) or a health education control program (n=30). The main outcome measure was polysomnographic sleep recordings, with additional measures of subjective sleep quality, physical activity, and physical fitness. Directional hypotheses were tested.
Results: Using intent-to-treat methods, at 12 months exercisers, relative to controls, spent significantly less time in polysomnographically measured Stage 1 sleep (between-arm difference=2.3, 95% confidence interval [CI], 0.7-4.0; p=003), spent more time in Stage 2 sleep (between-arm difference=3.2, 95% CI, 0.6-5.7; p=.04), and had fewer awakenings during the first third of the sleep period (between-arm difference=1.0, 95% CI, 0.39-1.55; p=.03). Exercisers also reported greater 12-month improvements relative to controls in Pittsburgh Sleep Quality Index (PSQI) sleep disturbance subscale score (p=.009), sleep diary-based minutes to fall asleep (p=.01), and feeling more rested in the morning (p=.02).
Conclusions: Compared with general health education, a 12-month moderate-intensity exercise program that met current physical activity recommendations for older adults improved some objective and subjective dimensions of sleep to a modest degree. The results suggest additional areas for investigation in this understudied area.