Children become less physically active and have longer screen-viewing as they transition into adolescence, with the greatest declines in physical activity and increases in inactivity and screen-viewing occurring between ages 8 to 10 years, and girls, Malay ethnicity, lower socioeconomic status, and less favourable maternal movement behaviours being key correlates.
Sleep declined by 3% from ages 5.5 to 12 years in a Singapore cohort of 837 children.
Light physical activity (LPA) declined by 24% from ages 5.5 to 12 years.
Moderate-to-vigorous physical activity (MVPA) declined by 44% from ages 5.5 to 12 years.
Inactivity increased by 26% from ages 5.5 to 12 years.
Screen-viewing increased by 155% from ages 5.5 to 12 years.
The period from ages 8 to 10 years represented the most pronounced phase of unfavourable change across multiple movement behaviours.
Being female was associated with less favourable movement behaviour profiles, including less sleep, higher inactivity and screen-viewing, and/or lower physical activity.
Malay ethnicity was associated with less favourable movement behaviour profiles in children.
Lower socioeconomic status was associated with less favourable movement behaviour profiles in children.
Maternal physical activity levels and sitting time were associated with children's sleep, inactivity, and MVPA up to age 8 years.
Maternal sitting and screen-viewing behaviours were associated with children's screen-viewing at all ages studied.
This research followed 837 children in Singapore from age 5.5 to 12 years, measuring how much they slept, moved, and sat still at four different points in time. The study found that as children grew older, they became substantially less active and spent far more time being inactive and watching screens. By age 12, children were doing about 44% less moderate-to-vigorous physical activity than they did at age 5.5 (dropping from about 71 to 40 minutes per day), their screen time had more than doubled (rising from about 1.8 to 4.6 hours per day, a 155% increase), and they were inactive for roughly 2 more hours each day. Notably, the sharpest and most rapid changes in all of these behaviours happened between ages 8 and 10, suggesting this is a particularly critical window. The study also identified groups of children who tended to fare worse. Girls, children of Malay ethnicity, and children from lower socioeconomic backgrounds consistently showed less sleep, more inactivity, more screen time, and less physical activity. Additionally, mothers' own habits mattered: when mothers were more physically active or sat less, their children tended to have better movement behaviours up to age 8, and mothers who spent more time sitting or watching screens tended to have children with higher screen time throughout the entire age range studied. This research suggests that efforts to keep children active and limit screen time may need to focus especially on the transition from primary school around ages 8 to 10, and should prioritise support for girls, lower-income families, and specific ethnic groups. The findings also highlight that encouraging mothers to be more physically active and reduce their own screen time could have a lasting positive effect on their children's habits, particularly in early childhood.
Tan S, Edney S, Padmapriya N, Tan S, Chong Y, Tan K, et al.. (2026). Sociodemographic and maternal-related correlates of children's movement behaviours from preschool to adolescence in Singapore: a longitudinal cohort study.. BMJ open. https://doi.org/10.1136/bmjopen-2025-105140