A prospective study on changes of cognitions, interpersonal influences, and physical activity in Taiwanese youth.

The decline of physical activity during adolescence is not well understood. This prospective study followed 969 Taiwanese students from eighth to ninth grade and examined their physical activity-related cognitions, interpersonal influences, and behavior of physical activity across the grade transition. Gender differences were found in the effects of the grade transition on physical activity and its related cognitions. The correlation coefficients showed moderate tracking for physical activity, cognitions, and interpersonal influences for both genders. The results also indicated that cognitions are more stable than behavior. The present study provides evidence of the decline in physical activity in Taiwanese youth across the grade transition as well as gender differences in the variables cognitions and interpersonal influences.