Self-determined to exercise? Leisure-time exercise behavior, exercise motivation, and exercise dependence in youth.

BACKGROUND Scant research has examined the determinants of primary exercise dependence symptoms in youth. Study purposes were to examine sex differences across leisure-time exercise behavior, motivation, and primary exercise dependence symptoms in youth and the extent to which exercise behavior and motivation predicted exercise dependence within the Self-Determination Theory framework. METHODS Adolescents (N = 805; mean age = 15 years; 46% girls) completed measures of exercise behavior, motivation, and exercise dependence in health/PE classes. RESULTS One-way ANOVA revealed boys scored higher than girls on leisure-time exercise behavior, exercise dependence symptoms, and most of the exercise motivation subscales. Hierarchical regression analyses indicated a) sex, exercise behavior, motivation, and their interaction terms explained 39% of the variance in primary exercise dependence; b) Integrated Regulation and Introjected Regulation were important determinants of exercise dependence; and c) sex moderated the contributions of External Regulation for predicting exercise dependence such that boys in the high and low external regulation groups had higher symptoms than girls in the high and low external regulation groups. CONCLUSIONS These preliminary findings support the controlled dimensions of Integrated Regulation (boys, girls), Introjected Regulation (boys, girls), and External Regulation (boys only) are important determinants of primary exercise dependence symptoms.