Author(s): PAN, M., HSU, W.-T., Institution: NATIONAL TAIPEI UNIVERSITY OF NURSING AND HEALTH SCIENCES, Country: TAIWAN, Abstract-ID: 520

Introduction
Declining physical activity levels among adolescents present a global health challenge, with student engagement in Physical Education (PE) often decreasing during secondary school years. The Constraints-Led Approach (CLA) has emerged as a promising student-centered pedagogy to address this issue by manipulating task, environmental, and individual constraints. However, the psychological mechanisms underlying how CLA-based strategies influence student behavioral engagement remain under-explored. This study aimed to investigate the relationship between Perceived Constraint Support (PCS), i.e., students' subjective experience of CLA strategies, and their effort in PE. Specifically, the study examined whether self-efficacy mediates the relationship between PCS and student effort.
Methods
Participants were 467 secondary school students recruited from Taiwan. Data collection was conducted in two phases separated by a one-month interval. In the first phase (T1), students completed the Constraints Support Scale in PE (CSS-PE) to measure PCS. One month later (T2), the same participants completed the Tripartite Efficacy Beliefs Instrument (TEBI) to assess self-efficacy and the Students' Responsibility in PE Scale (SRIPE) to measure effort. Structural Equation Modeling was conducted using AMOS software. Model fit was evaluated using standard indices, including Chi-square/df, CFI, TLI, RMSEA, and SRMR. The mediation effect of self-efficacy was tested using bias-corrected bootstrapping with 2,000 resamples and a 95% confidence interval (CI).
Results
SEM demonstrated an excellent fit to the observed data (Chi-square/df = 2.00; CFI = .97; TLI = .97; RMSEA = .05; SRMR: .04). Path analysis indicated that PCS measured at T1 had a strong, positive direct effect on self-efficacy measured at T2 (standardized coefficient = .64, p < .001) and a significant direct effect on student effort at T2 (standardized coefficient = .32, p < .001). Furthermore, self-efficacy significantly and positively predicted student effort (standardized coefficient = .46, p < .001). The bootstrap analysis revealed a significant partial mediation effect. The standardized indirect effect of PCS on effort through self-efficacy was .29, with a 95% CI of [.214, .386], which did not include zero.
Discussion
The findings provide empirical evidence that PCS is a significant predictor of future student effort in PE. Importantly, the results highlight the mediating role of self-efficacy, suggesting that when teachers effectively manipulate constraints, a core component of PCS, it enhances students' belief in their capabilities over time. This increased self-efficacy, in turn, fuels greater behavioral investment and effort. These results support the application of the CLA not only for skill acquisition but also for fostering psychological engagement. Educators are encourage d to design supportive constraint-based environments to promote sustainable active participation in PE.