Does autonomous motivation and self-efficacy mediate associations between environmental factors and physical activity in adolescents?

Background: To analyze the associations among autonomous motivation, self-efficacy, satisfaction of basic psychological needs, social support and perceived environment with physical activity practice of adolescents aged between 12 and 15 years; and to test autonomous motivations and self-efficacy as potential mediators of the associations between these environmental factors and physical activity practice.

Methods: We evaluated 553 adolescents, that participated in the ActTeens Program. Physical activity was assessed using the Physical Activity Questionnaire for Adolescents. Autonomous motivation, self-efficacy, satisfaction of basic psychological needs, parents' social support and perceived environment were assessed using specifics questionnaires. Linear regression models were used to test the associations.

Results: Parents' support (β = 0.32), satisfaction of basic psychological needs of colleagues (β = 0.21) and teachers (β = 0.12), and perceived environment (β = 0.10) had significant associations with physical activity (p < 0.05). The direct effect value was reduced when autonomous motivation was added as a mediator of the association between parents' support and physical activity (β = 0.24), with a 25% mediated effect. Autonomous motivation was mediator of the relationship between basic psychological needs of colleagues (β = 0.13; EM = 38%), teachers (β = 0.02; EM = 83%), and perceived environment (β = 0.03; EM = 70%) with physical activity.

Conclusion: Self-efficacy was not associated with physical activity and autonomous motivation was an important mediator of adolescents' physical activity.