Sitting Less, Moving More: A Compositional Data Analysis of Movement Behaviours and Adolescent Health‐Related Quality of Life

AIM: To predict changes in health-related quality of life (HRQoL) when sedentary behaviour was hypothetically replaced with other movement behaviours (sleep, standing, light physical activity and moderate-to-vigorous physical activity) in adolescents. METHODS: Participants (N = 216; 12-17 years) provided measures of HRQoL and accelerometer-measured movement behaviours at two time-points, separated by 1 year. HRQoL was assessed with the KIDSCREEN-27 questionnaire. Compositional linear mixed models were used to estimate changes in HRQoL when time was reallocated from sedentary behaviour to other movement behaviours. RESULTS: Favourable changes in global HRQoL scores (Δ (95% CI)) were predicted when 30 min/day of sedentary behaviour was substituted with light physical activity in girls (2.0 (0.7, 3.3)), moderate-to-vigorous physical activity in boys [1.8 (0.5, 3.2)], or sleep in all participants [0.4 (0.0, 0.8)]. Reallocating time from sedentary behaviour to standing had no impact on HRQoL. CONCLUSION: Sitting less, moving more is associated with better HRQoL in adolescents whilst replacing sitting with standing has no impact on HRQoL. The optimal intensity of movement for HRQoL differs between girls (light) and boys (moderate-to-vigorous).