Abstract
This study aimed to examine the associations and reciprocal predictive relationships between parental exercise support and adolescents' physical activity (PA) intentions and behaviors. A total of 1482 adolescents from central and southern China were assessed at two time points over one year using the Parental Exercise Support Scale, PA Intention Scale, and PA Rating Scale. Cross-lagged panel analyses were conducted using Mplus 8.7. (1) Significant synchronous and longitudinal correlations were observed among parental exercise support, PA intentions, and PA behaviors; (2) Parental exercise support at Time 1 (T1) positively predicted adolescents' PA intentions and behaviors at Time 2 (T2), and T1 PA behavior also positively predicted T2 parental exercise support; (3) A bidirectional predictive relationship was found between PA intentions and PA behaviors. Parental exercise support is a key external factor influencing adolescents' PA intentions and behaviors. It not only positively predicts future PA motivation and engagement but is also reflects by adolescents' actual participation in PA.