Public health advocates have been calling for an intensified focus on early, middle, and late adolescence health behaviours due to both the short- and long-term health consequences. Hence, both the health-risk (e.g., alcohol consumption) and health-promoting (e.g., physical activity) behaviours of adolescents have been widely studied to better understand the underlying causes or determinants with an eye towards implementing more effective interventions. The success of these interventions, typically grounded in a risk-reduction/prevention-oriented intervention approach has been modest, especially those focused on health-promoting behaviours, such as physical activity. The purposes of this paper are to (1) conduct a conceptual critique of the risk-reduction/prevention-oriented approach underlying traditional adolescent physical activity interventions, and (2) examine the potential usefulness of an emerging person-based, development-oriented (PBDO) approach for enhancing the motivation and sustainability of adolescent physical activity. Within this PBDO perspective, emphasis is on adolescent growth and development as the starting point for initiating and sustaining physical activity. Implications of the PBDO approach for adolescent physical activity interventions are presented.