Lack of perceived sleep improvement after 4-month structured exercise programs

Objective: Many middle-aged women experience decreases in their sleep quality during the menopausal transition. Physical activity has been shown to improve sleep, but few randomized, controlled trials investigating such effects in this population exist. In 164 previously low-active middle-aged women (mean age = 49.9, SD = 3.6), using a 4-month randomized, controlled trial, we examined structured exercise in the form of walking or yoga to determine the effects on perceived sleep quality. Design: Participants completed body composition and fitness assessments and a battery of psychological measures, including the Pittsburgh Sleep Quality Index, at the beginning and end of a 4-month randomized, controlled exercise trial with three arms: walking, yoga, and control. Results: A series of mixed-model repeated-measures univariate analyses of covariance did not reveal any statistically significant intervention effects for total sleep quality or any individual sleep-quality domain. The pattern of effect sizes indicated that the walking group tended to experience small improvements in five of the seven assessed sleep-quality domains. Residual changes in menopausal symptoms and depression were associated with residual changes in total sleep quality. However, after controlling for the effects of physical activity, only menopausal symptoms contributed a unique amount of variance in residual change in total sleep quality. Conclusions: In this study, 4-month moderate-intensity walking and low-intensity yoga programs were ineffective in yielding statistically significant improvements in sleep quality. Exercise interventions of longer durations or greater intensity may be needed for such improvements.