Hofman A, Voortman T, Ikram MA, et al. - In view of the studies describing a potential correlation of physical activity, sedentary behavior and sleep with the risk of mental health disorders, researchers herein investigated the correlations of reallocations of time among older adults’ physical activity, sedentary behavior and sleep with depressive and anxiety symptoms utilizing compositional isotemporal substitution analyses. From the population-based Rotterdam Study, a total of 1,943 participants (mean age 71 years, SD: 9; 52% women) were included. Accelerometer data (mean duration 5.8 days, SD: 0.4) on physical activity, sedentary behavior and sleep and self-reported data on depressive symptoms and anxiety were obtained between 2011 and 2016. Findings revealed less depressive symptoms in correlation with replacing sedentary behaviour or sleep with more moderate-to-vigorous physical activity, indicating the relevance of mainly intensive types of physical activity for middle-aged and older adults in relation to depressive symptoms.