Physical activity, sedentary time, and sleep from childhood to young adulthood: a seven-wave cohort study of within-person relations

Abstract

Study Objectives: To determine whether within-person changes in total physical activity (PA), moderate-to-vigorous physical activity (MVPA), and sedentary time from ages 6 to 18 predict changes in sleep duration and insomnia symptoms, and vice versa. Methods: Seven waves of biennially collected data from a birth cohort study were used, capturing ages 6–18 years (n = 880). Every second year, objective data on PA, sedentary time, and sleep duration were collected using accelerometers, while insomnia symptoms were assessed through clinical interviews. Random Intercept Cross-Lagged Panel Models were estimated to test the within-person relations between PA/MVPA/sedentary time and sleep. Potential sex and age differences were also examined. Results: We found no evidence for within-person relations between the study variables, nor for any sex or age differences. Conclusions: Children and adolescents who become more physically active or spend less time in sedentary activities are probably not more likely to sleep longer or better than they typically would.