Chinese Center for Disease Control and Prevention;
Beijing 102206;
China;
National Institution for Nutrition and Health;
Chinese Center for Disease Control and Prevention;
Beijing 100050;
China;
Chinese University of Hong Kong;
Hong Kong 999077;
China;
Center for Exercise;
Nutrition and Health Sciences;
School for Policy Studies;
University of Bristol;
Bristol;
BS81TZ;
UK;
Physical activity; Sedentary behaviors; Trends; Correlates; China; Children;