Physical activity, physical fitness, and body mass index in the Chinese child and adolescent populations： An update from the 2016 Physical Activity and Fitness in China The Youth Study

In this special issue of the Journal of Sport and Health Science,analyses of the most recent national prevalence estimates from the 2016 Physical Activity and Fitness in China—The Youth Study(PAFCTYS)are presented.These include the prevalence of moderate-to-vigorous physical activity(MVPA)。

Prevalence and correlates of meeting the muscle-strengthening exercise recommendations among Chinese children and adolescents:Results from 2019 Physical Activity and Fitness in China—The Youth Study

Purpose This study aimed to describe the national prevalence of Chinese children and adolescents who met the World Health Organization muscle-strengthening exercise(MSE)recommendations and identify correlates of meeting the MSE recommendations.Methods Cross-sectional data from the 2019 Physical Activity and Fitness in China—The Youth Study,a nationally representative sample of Chinese children and adolescents(n=80,413;mean age=13.7 years;53.9%girls)and their parents,were analyzed.Children and adolescents who reported engaging≥3 days(up to 7 days)of MSE per week were classified as meeting the MSE recommendations.MSE,demographics,lifestyle behaviors(sport participation,moderate-to-vigorous physical activity,screen time,and sleep duration),exercise intention,peer and parental support,and parental MSE participation were assessed through self-reports.Logistic regression models were used to determine the correlates of meeting the MSE recommendations.The analyses were completed in 2020.Results Overall,39.3%of children and adolescents met the MSE recommendations.Girls,10th-12th graders,minorities,those from lower income households and those from families with lower parental education were less likely to meet the MSE recommendations.Children and adolescents who were proficient in≥2 sports were more likely to meet the MSE recommendations(adjusted odds ratio(aOR)=1.44,95%confidence interval(95%CI):1.26-1.65),as were those with more moderate-to-vigorous physical activity(aOR=1.57,95%CI:1.53-1.61).Additionally,children and adolescents with high exercise intention(aOR=1.60,95%CI:1.51-1.69),those whose parents met the adult MSE recommendations(aOR=1.46,95%CI:1.40-1.52),and those who received high peer(aOR=1.27,95%CI:1.20-1.34)and parental support(aOR=1.07,95%CI:1.04-1.12)were more likely to meet the MSE recommendations.Conclusion Less than two-fifths of Chinese children and adolescents met the World Health Organization MSE recommendations.The correlates identified in our study can help inform the development of school and community based strategies and policies to enhance participation in MSE and improve muscular fitness of all Chinese children and adolescents.

Meeting 24-h movement guidelines: Prevalence, correlates, and the relationships with overweight and obesity among Chinese children and adolescents

Background:Meeting 24-h movement guidelines by children and adolescents has been associated with improved indicators of health,although it has been under-studied in China.Hence,this study aimed to investigate the prevalence of meeting the 24-h movement guidelines,its correlates,and its relationships with body mass index in children and adolescents in China.Methods:Cross-sectional data from the 2017 Youth Study in China of 114,072 children and adolescents(mean age=13.75 years,49.18%boys)were used.Meeting 24-h movement guidelines(60 min of daily moderate-to-vigorous physical activity,2 h of daily leisure screen time,911 h and 810 h nightly sleep duration for 613-year-olds and 1417-year-olds,respectively)and height and weight of all participants were assessed.The prevalence of meeting the 24-h movement guidelines and World Health Organization weight status categories were determined.Generalized linear models were used to determine the correlates of meeting the 24-h movement guidelines and the relationships of meeting the 24-h movement guidelines with overweight(OW)and obesity(OB).Results:Only 5.12%of Chinese children and adolescents met the 24-h movement guidelines,and 22.44%were classified as OW/OB.Older children and adolescents were less likely to meet the 24-h movement guidelines.Parental education level and family income were positively related to meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines showed lower odds ratios for OW/OB.Compared with participants meeting the 24-h movement guidelines,boys in 4th6th grades met none of the recommendations(OR=1.22,95%CI:1.061.40),met the screen time recommendation only(OR=1.13,95%CI:1.011.28),met the nightly sleep duration recommendation only(OR=1.14,95%CI:1.031.28),and had significantly higher odds ratios for OW/OB.Similar trends were observed for girls in 4th6th grades:meeting none of the guidelines(OR=1.35,95%CI:1.141.59),meeting sleep duration guidelines only(OR=1.23,95%CI:1.081.39),and meeting moderate-to-vigorous physical activity+nightly sleep duration guidelines(OR=1.24,95%CI:1.011.54).For girls in 7th9th grades,the following trend was observed:meeting none of the guidelines(OR=1.30,95%CI:1.011.67).Conclusion:Very few Chinese children and adolescents met the 24-h movement guidelines.Age(negatively correlated),parental education level,and family income(both positively correlated)were correlates of meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines were more likely to have lower risks for OW/OB,especially in the youngest age group(Grades 46);and girls in the middle age group(Grades 79)were also more likely to have lower risks for OW/OB.Further research studies should explore additional correlates and determinants for meeting the 24-h movement guidelines.Also,future studies should use longitudinal or interventional designs to determine the relationships between meeting the 24-h movement guidelines and OW/OB and other health indicators,while taking sex and age differences into account.