Attitudes Towards Sport in Early Adolescence: A Scale Adaptation Study for Sustainable Good Health and Well-Being

Background: The decline in physical activity during the transition to early adolescence poses a significant threat to lifelong health and well-being, directly impacting the targets of Sustainable Development Goal 3 (SDG 3). To design effective preventive interventions, researchers need developmentally appropriate tools to measure the psychological drivers of physical activity. Objectives: This study aimed to adapt and validate the Attitude To-wards Sport Scale (ATSS), originally developed for high school students, for a middle school population (ages 10–15). Methods: We used a mixed-methods approach, starting with cognitive think-aloud protocols to ensure semantic suitability, followed by a cross-sectional survey of 531 students. Data were analyzed using robust Confirmatory Factor Analysis (CFA). Results: The results confirmed that the original three-factor struc-ture (Interest, Lifestyle, and Participation) perfectly fit the early adolescent sample. The scale demonstrated high composite reliability across all dimensions. Furthermore, the adapted ATSS showed strong criterion-related validity through high correlations with perceived physical literacy and actual physical activity durations. It also successfully dif-ferentiated between licensed athletes and non-licensed students. Conclusions: We con-clude that the adapted ATSS is a highly reliable and developmentally sensitive screening tool for pediatricians, educators, and public health professionals to monitor youth sports engagement and promote sustainable health-lifestyle behaviors.