Objectives To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China. Methods The study design was one-year cluster randomized control...Objectives To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China. Methods The study design was one-year cluster randomized controlled trial of physical activity intervention （20 rain of daily exercise in the classroom） with an additional year of follow-up among 4 700 students aged 8-11 years at baseline. Results After the one-year intervention, BMI increased by 0.56 kg/m2 （SD 1.15） in the intervention group and by 0.72 kg/m^2 （SD 1.20） in the control group, with a mean difference of-0.15 kg/m^2 （95% CI： -0.28 to -0.02）. BMI z score decreased by -0.05 （SD 0.44） in the intervention group, but increased by 0.01 （SD 0.46） in the control group, with a mean difference of-0.07 （-0.13 to -0.01）. After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI （-0.13, -0.25 to -0.01 ）, BMI z score （-0.05, -0.10 to -0.01）, fat mass （-0.27 kg, -0.53 to -0.02） and percent body fat （-0.53, -1.00 to -0.05）. The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 （P-0.008） and year 2 （P=-0.04）. Conclusions These findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.展开更多
基金supported by Nutricia Research Foundation. The clinical trial registration number is ChiCTR-TRC-00000053
文摘Objectives To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China. Methods The study design was one-year cluster randomized controlled trial of physical activity intervention （20 rain of daily exercise in the classroom） with an additional year of follow-up among 4 700 students aged 8-11 years at baseline. Results After the one-year intervention, BMI increased by 0.56 kg/m2 （SD 1.15） in the intervention group and by 0.72 kg/m^2 （SD 1.20） in the control group, with a mean difference of-0.15 kg/m^2 （95% CI： -0.28 to -0.02）. BMI z score decreased by -0.05 （SD 0.44） in the intervention group, but increased by 0.01 （SD 0.46） in the control group, with a mean difference of-0.07 （-0.13 to -0.01）. After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI （-0.13, -0.25 to -0.01 ）, BMI z score （-0.05, -0.10 to -0.01）, fat mass （-0.27 kg, -0.53 to -0.02） and percent body fat （-0.53, -1.00 to -0.05）. The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 （P-0.008） and year 2 （P=-0.04）. Conclusions These findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.
