Perceived physical education teacher autonomy support and intention to be physically active among Chinese senior high school students: cross-sectional serial indirect associations involving physical activity enjoyment and exercise identity.

Background: Perceived physical education teacher autonomy support may be associated with students' intentions to be physically active, but the distinct and joint roles of physical activity enjoyment and exercise identity remain unclear. This study examined specific and serial indirect associations involving these constructs and whether conclusions depended on mediator ordering. Methods: A cross-sectional survey included 1,824 students from four general senior high schools in Luoyang, Henan Province, China. Participants completed 29 self-report items assessing the four constructs. Maximum-likelihood latent-variable structural equation modeling was the primary analysis. The hypothesized ordering, with physical activity enjoyment before exercise identity, and the reversed ordering were evaluated using 5,000 percentile bootstrap resamples. A composite-score regression-based serial indirect-effects analysis adjusted for gender, age, and grade served as a robustness check. Results: The hypothesized-order model fit well, with a comparative fit index of 0.996, a root mean square error of approximation of 0.013, and a standardized root mean square residual of 0.016. Perceived physical education teacher autonomy support showed positive total and direct associations with intention to be physically active, with standardized estimates of 0.488 and 0.295, respectively. The specific indirect associations through physical activity enjoyment and exercise identity were both nonzero, with a standardized estimate of 0.084 and a 95% confidence interval of [0.058, 0.111] for each. The serial indirect association through physical activity enjoyment followed by exercise identity was nonzero, with a standardized estimate of 0.025 and a 95% confidence interval of [0.017, 0.035]. The reversed-order model had identical fit and produced a nonzero serial indirect association, with a standardized estimate of 0.040 and a 95% confidence interval of [0.027, 0.054]. The hypothesized-order model explained 32.6% of the variance in intention to be physically active, and the robustness analysis was directionally consistent. Conclusion: Perceived physical education teacher autonomy support, physical activity enjoyment, and exercise identity were statistically associated with intention to be physically active. Because both mediator orderings were compatible with the cross-sectional data, the findings do not establish a unique temporal or causal sequence; the outcome reflects intention rather than actual physical activity behavior.