Sleep health mediates the relationship between physical activity and depression symptoms

Purpose This study aimed to investigate cross-sectional associations between physical activity, sleep health, and depression symptoms using mediation models. Methods Participants (N = 1576, M-Age = 39.3 years, 40% female) were recruited online from Amazon's Mechanical Turk crowd-sourcing service. Physical activity was measured using a single-item self-report measure and depression symptoms were reported using the Hospital Anxiety and Depression Scale. Sleep health was measured using the 6-question RUSATED Sleep Health survey V2.0. Results Good sleep health (direct effect: beta = - .273, t = - 13.87, p < .0001) and high levels of physical activity (direct effect: beta = - .092, t = - 4.73, p < .0001) were both individually associated with fewer depression symptoms. Sleep health significantly mediated 19% of the association between physical activity and depression symptoms (indirect effect: beta = - .022, 95% CI [- .036 to - .008]), while physical activity significantly mediated 3% of the relationship between sleep health and depression symptoms (indirect effect: beta = - .008, 95% CI [- .014 to - .003]). Conclusion Physical activity and sleep health act as predictors and mediators of depression symptoms.