Effects of moderate-intensity exercise on polysomnographic and subjective sleep quality in older adults with mild to moderate sleep complaints

Abstract

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. Copyright 2008 by The Gerontological Society of America.