Abstract
PURPOSE: Using a longitudinal cross-lagged design, this study examines the intrinsic relationship between family closeness, social support, and adolescent physical activity. METHODS: Using the Family Intimacy Questionnaire, Social Support Rating Scale (SSRS), and Physical Activity Rating Scale (PARS), a two-phase longitudinal study was conducted on 802 adolescents (52.5% female) with a three-month interval between assessments. RESULTS: (1) For adolescents, significant gender differences were found in family closeness, social support, and physical activity (p < 0.01); (2) Correlation analysis revealed positive pairwise correlations among family closeness, social support, and physical activity (all p < 0.01); (3) Cross-lagged analysis indicated that T1 family closeness significantly and positively predicted T2 social support (β = 0.30, p < 0.01), while T1 social support also significantly and positively predicted T2 family closeness (β = 0.30, p < 0.01). Furthermore, T1 family closeness significantly and positively predicted T2 physical activity (β = 0.29, p < 0.01), and T1 physical activity significantly and positively predicted T2 family closeness (β = 0.17, p < 0.01); T1 social support significantly and positively predicted T2 physical activity (β = 0.36, p < 0.01), and T1 physical activity significantly and positively predicted T2 social support (β = 0.22, p < 0.01). CONCLUSION: (1) Significant gender differences exist in family closeness, social support, and physical activity among children and adolescents; (2) Family closeness and social support are positively correlated with adolescent physical activity; (3) Within the adolescent cohort, family closeness and social support cross-predict physical activity over time, while social support and physical activity also cross-predict each other over time.