Fig. 1

a-d. Trends in adjusted means for physical activity (MET-hours/week) in Chinese school children by gender and age group, China Health and Nutrition Survey (CHNS)^a. ^a Means are adjusted for wave-specific income tertile, urbanicity index, maternal education, and child age. ^* P-value <.05 from post-hoc test of linear trend. ^** P-value <.001 from post-hoc test of linear trend