Influences of Policy, School, Family, and Community Environmental Factors on Physical Activity and Fitness Among Children and Adolescents: A Structural Equation Modeling Analysis

Background: Investigating environmental factors' impact on youth physical activity (PA) and fitness (PF) is crucial for healthy lifestyle promotion. This study examines policy, school, family, and community influences on Chinese children and adolescents' PA and PF. Methods: In a cross-sectional analysis involving 2,747 Chinese children and adolescents (mean age 12.90 ± 2.49; 48.2% male) from 17 schools, environmental factors—policy, school, family, and community—were assessed through questionnaires, while PA levels were gauged using the International Physical Activity Questionnaire-Short Form. PF metrics—BMI, waist-to-height ratio, grip strength, vertical jump, and 20-mSRT—were measured onsite. Structural Equation Modeling (SEM) explored relationships between environmental influences and PA/PF outcomes. Results: School environment ranked highest (78.0±9.5), with community environment lowest (38.7±18.0). Family environment significantly positively influenced low-intensity PA (LPA) (β=0.102, P<0.001) but negative effect on moderate to vigorous PA (MVPA) (β=-0.055, P=0.035). Community and policy environment positively impacted MVPA (β=0.216, P<0.001; β=0.072, P=0.009, respectively). Family environment positively affected BMI reduction (β=-0.103, P<0.001) but negatively grip strength (β=-0.063, P=0.018). Community environment significantly improved grip strength and 20-mSRT performance (β=0.088, P=0.002; β=0.065, P=0.027). Conclusions: This study reveals that policy environment directly and positively influence MVPA among Chinese youth. Although school environment score highest, they show no significant association with PA or PF. Family environment is conducive to LPA but inversely related to MVPA, while positively impacting BMI reduction and negatively affecting grip strength development. In contrast, community environment, despite scoring the lowest, positively affect MVPA, grip strength, and 20-mSRT outcomes. This study emphasizes the importance of policy, family, and community environments in influencing youth PA and PF, advocating for the improvement of community sports infrastructure and the promotion of MVPA benefits within families.