To examine differences in patterns of objectively measured physical activity (PA) among weekdays and weekend days and across different time blocks during the day in relation to age and gender. This knowledge is important when planning preventive initiatives aimed at increasing levels of PA in children. This is a cross-sectional analysis in 653 girls and 640 boys (6-10 yr) measured during 1 wk with accelerometry. Periods of the day were divided into school time (8:00 a.m. to 1:30 p.m.), after school care time (1:30-4:00 p.m.), and evening time (4:00-9:00 p.m.). Multivariate ANOVA was used to analyze mean PA. Mean daily PA differed significantly across age groups (6-10 yr) in both boys and girls (P < 0.001). Mean (SE) daily PA was significantly lower during weekends compared with weekdays in all age groups (girls 782 (6.7) vs 681 (7.7) counts per min (CPM), P < 0.001; boys 853 (7.1) vs 729 (8.0) CPM, P < 0.001). This decline was similar across low, medium, and highly active children. Mean PA was highest during after school care time on weekdays (girls 879 (9.8) and boys 990 (10.0) CPM) compared with all other periods. The difference in mean PA between boys and girls was highest during school time (P < 0.001) and after school care time (P < 0.001). The decline in PA in children may start already at the age of 6 yr. The school setting may be an important arena for targeting activity levels in girls because the difference in PA levels between girls and boys is most pronounced during school time. In both girls and boys, PA levels are disproportionally low during weekends and might be important targets for interventions aimed to increase PA.
