Current evidence is unclear due to methodological limitations. We bridge critical knowledge gaps by quantifying the longitudinal changes in movement behaviours and their correlates from early childhood through adolescence.

Longitudinal observational cohort study.

General healthy child and adolescent sample in Singapore.

Growing Up in Singapore Towards healthy Outcomes study participants.

We used wrist-worn accelerometry and proxy-reported data to examine movement behaviours (sleep, inactivity, light physical activity (PA; LPA) and moderate-to-vigorous PA (MVPA) and screen-viewing) at ages 5.5, 8, 10 and 12 years and the sociodemographic and maternal lifestyle-related correlates using linear regression models with generalised estimating equations.

Among 837 children, sleep, LPA and MVPA declined by 3% (from 9.1 to 8.8 hours/day), 24% (from 5.8 to 4.4 hours/day) and 44% (from 71.3 to 40.1 min/day), respectively, while inactivity and screen viewing increased by 26% (from 8.0 to 10.1 hours/day) and 155% (from 1.8 to 4.6 hours/day), respectively, from ages 5.5 to 12 years. The greatest annual increase in inactivity (0.6 hour/annum) and screen-viewing (0.8 hour/annum) and decrease in LPA (0.3 hour/annum) and MVPA (10.4 min/annum) occurred from ages 8 to 10 years. Girls of Malay ethnicity and lower socioeconomic status, and whose mothers had less favourable movement behaviours, had significantly less sleep, higher inactivity and screen-viewing and/or lower PA. Maternal PA levels and/or sitting time were associated with children’s sleep, inactivity and MVPA up to age 8 years, while maternal sitting and screen-viewing behaviours were associated with children’s screen-viewing at all ages.

Using contemporaneous datasets relevant to the present day, we confirmed that children become less physically active and have longer screen-viewing as they transition into adolescence and highlighted characteristics to be prioritised in future interventions.