This systematic review examines the empirical literature on the relationships between key constructs of self-determination theory (SDT) and exercise and physical activity behaviors. It includes 66 studies published up to June 2011, analyzing the relationships between SDT-based constructs such as autonomy/need support, need satisfaction, exercise motives, and self-regulation with exercise and physical activity outcomes. The review also examines SDT-based interventions aimed at increasing exercise behavior. The results show consistent support for a positive relationship between more autonomous forms of motivation and exercise behavior. Identified regulation predicts initial/short-term adoption more strongly than intrinsic motivation, while intrinsic motivation is more predictive of long-term exercise adherence. Competence satisfaction and more intrinsic motives positively predict exercise participation across various samples and settings. Mixed evidence was found regarding the role of other motives, such as health/fitness and body-related motives, and the specific nature of introjected regulation. Most studies used descriptive designs, but similar results were found across cross-sectional, prospective, and experimental designs. The literature provides good evidence for the value of SDT in understanding exercise behavior, highlighting the importance of autonomous (identified and intrinsic) regulations in fostering physical activity. However, there are inconsistencies and mixed evidence regarding the relationships between specific SDT constructs and exercise. The review discusses limitations in the literature and suggests ways to refine the application of SDT to exercise and physical activity promotion, integrating these with future research avenues. The review also highlights the importance of basic psychological needs (autonomy, competence, relatedness) in promoting exercise behavior, and the role of goal contents in exercise motivation. The review concludes that SDT offers a comprehensive framework for understanding exercise behavior, with autonomous motivations being most effective in promoting sustained physical activity.This systematic review examines the empirical literature on the relationships between key constructs of self-determination theory (SDT) and exercise and physical activity behaviors. It includes 66 studies published up to June 2011, analyzing the relationships between SDT-based constructs such as autonomy/need support, need satisfaction, exercise motives, and self-regulation with exercise and physical activity outcomes. The review also examines SDT-based interventions aimed at increasing exercise behavior. The results show consistent support for a positive relationship between more autonomous forms of motivation and exercise behavior. Identified regulation predicts initial/short-term adoption more strongly than intrinsic motivation, while intrinsic motivation is more predictive of long-term exercise adherence. Competence satisfaction and more intrinsic motives positively predict exercise participation across various samples and settings. Mixed evidence was found regarding the role of other motives, such as health/fitness and body-related motives, and the specific nature of introjected regulation. Most studies used descriptive designs, but similar results were found across cross-sectional, prospective, and experimental designs. The literature provides good evidence for the value of SDT in understanding exercise behavior, highlighting the importance of autonomous (identified and intrinsic) regulations in fostering physical activity. However, there are inconsistencies and mixed evidence regarding the relationships between specific SDT constructs and exercise. The review discusses limitations in the literature and suggests ways to refine the application of SDT to exercise and physical activity promotion, integrating these with future research avenues. The review also highlights the importance of basic psychological needs (autonomy, competence, relatedness) in promoting exercise behavior, and the role of goal contents in exercise motivation. The review concludes that SDT offers a comprehensive framework for understanding exercise behavior, with autonomous motivations being most effective in promoting sustained physical activity.