High or increasing levels of physical activity protect women from future insomnia

Abstract Objective There is a lack of evidence about the impact of physical activity on insomnia based on representative samples with a long-term follow-up. The aim of this study was to assess the impact of physical activity on insomnia incidence, as well as the impact of changes in leisure-time physical activity on insomnia in women. Method The study included a population-based sample of 5062 women aged >20 years who responded to questionnaires in 2000 and 2010. Insomnia was defined as experiencing severe or very severe problems in falling asleep, maintaining sleep, or experiencing early morning awakenings, together with daytime sleepiness or fatigue. Physical activity was categorized as low, medium, or high level at baseline and at follow-up. Results After adjusting for age, body mass index, smoking, alcohol dependence, snoring status, level of education, and psychological distress, the adjusted odds ratio (OR) (95% confidence interval) for incident insomnia in women who increased from a low to a medium or high level of physical activity was 0.53 (0.3–0.94) and 0.17 (0.03–0.81), respectively, as compared to women with a low activity level on both occasions. Women remaining on a medium activity level or increasing to a high activity level had an OR of 0.53 (0.35–0.83) and 0.36 (0.21–0.64) and the OR of those decreasing from a high level to a medium level or remaining on a high activity level on both occasions was 0.37 (0.21–0.66) and 0.3 (0.16–0.54) respectively. Conclusion Women maintaining higher levels or increasing their level of leisure-time physical activity over the 10-year period were partly protected from self-reported insomnia.