Knowing that children—s and adolescents— physical activity should be increased is not enough to enhance their activity frequency, intensity, and duration. Motivating youth to initiate, continue, and sustain physical activity enables them to embrace an active lifestyle that leads to a variety of health benefits. An understanding of the psychological and social predictors of physical activity behaviors is essential to contributing to active lifestyles. Adults in children—s lives can structure everyday environments in ways that enhance children—s motivation for physical activity. The pathways to enhancing physical activity motivation, activity behaviors, and positive health outcomes include 4 common elements or ingredients: feelings of competence, perceptions of choice or autonomy, supportive relationships, and enjoyment of activity participation. Simply providing information to youth about benefits, frequency, and duration of physical activity is not sufficient for enhancing physical activity behavior. Subtle changes in framing physical activities can have a dramatic influence on youths— physical activity motivation and behaviors. Adults should encourage youth to participate in activities they find enjoyable, feel competent doing, have chosen to do, and that include positive social support—these conditions optimize their motivation for sustaining physical activity and thus the physical, social, and psychological health benefits afforded from such participation. © 2010, SAGE Publications. All rights reserved.