Associations between 24-hour movement behaviours and psychological wellbeing in adolescents using compositional data analysis

Adolescent psychological wellbeing is a critical determinant of lifelong health. Global data suggest a concerning decline in adolescent wellbeing. While the 24-hour movement behaviours, moderate to vigorous physical activity (MVPA), light physical activity (LPA), sedentary time, and sleep, have been linked to mental health outcomes; their associations with specific domains of adolescent psychological wellbeing remain underexplored. This study used compositional data analysis (CoDA) to examine how time-use relate to domain-specific wellbeing in Australian secondary school adolescents. Data were drawn from 124 adolescents (aged 13–17 years) participating in the TransformUs Secondary effectiveness trial. Wrist worn Actigraph GT9X accelerometer captured 24-hour movement behaviour over at least three valid days (≥ 16 h/day). Wellbeing was assessed using the EPOCH Measure of Adolescent Wellbeing, which includes five domains: engagement, perseverance, optimism, connectedness, and happiness. CoDA was used to examine associations between the composition of daily movement behaviours and EPOCH domains using isometric log-ratio (ILR) transformations. A compositional time reallocation analysis (30-minutes) was also performed to explore hypothetical associations with wellbeing outcomes. The average daily time-use composition was 680.9 min (47.3%) sedentary time, 473.0 min (32.8%) sleep, 250.7 min (17.4%) LPA, and 35.3 min (2.5%) MVPA. Greater time spent in LPA relative to other behaviours was significantly associated with higher happiness scores (p < 0.05), while greater sedentary time relative to LPA was negatively associated with happiness. Reallocating 30 min of sedentary time to LPA was associated with significant increases in happiness (β = 0.128, 95% CI: 0.034, 0.222). No significant associations were found for engagement, perseverance, or optimism. Adolescent daily movement behaviour composition was associated with domain-specific psychological wellbeing, particularly happiness. LPA was a potential contributor to positive psychological wellbeing. These findings suggest that even modest changes in daily routines, such as replacing sedentary time and LPA, may support adolescent flourishing. Future research should confirm these findings longitudinally and employ in intervention studies.