Examining the construct validity and stability of physical literacy in adolescents and its longitudinal relationship with physical activity

Physical literacy (PL) is a multidimensional construct encompassing motivation, confidence, physical competence, and knowledge/understanding to engage in lifelong physical activity (PA). While widely endorsed, few studies have empirically validated PL. This study aimed to validate the PL construct, examine its stability over time, and assess its role in predicting future PA among adolescents. PL was assessed annually over three time points in 1,081 adolescents (548 girls, 533 boys; mean age = 12.28 ± 0.33 years at baseline), using validated questionnaires and school-based field tests across four PL domains. A second-order confirmatory factor analysis (CFA) was conducted to identify the latent structure of PL. Longitudinal CFA evaluated the construct's stability, and an autoregressive cross-lagged panel model tested predictive associations between PL and future PA behaviour. The second-order CFA confirmed the multidimensional structure of PL. Longitudinal CFA supported the construct's stability, with partial scalar invariance indicating a consistent model across time. The autoregressive cross-lagged panel model revealed that PL significantly predicted PA engagement in subsequent years. This study empirically validates PL as a stable and multidimensional construct, demonstrating its predictive value for adolescent PA. Findings support PL as a crucial determinant of health and underscore the importance of fostering PL through targeted youth interventions and PA programmes.