Need-supportive digital sports platform and physical activity outcomes in university physical education: an intact-class quasi-experimental study based on self-determination theory.

Introduction: Digital platforms are increasingly used in university physical education (PE), but the psychological pathways associated with platform-supported PE remain insufficiently understood. Because individual random assignment was not feasible in the authentic educational setting, this study examined post-intervention group differences and self-determination theory (SDT)-consistent associations, distinguishing need satisfaction from need frustration. Methods: An 8-week post-intervention intact-class quasi-experimental study was conducted in eight university table tennis classes. The final sample included 393 first- and second-year undergraduate students aged 18-21 years (control group, Results: The platform-supported group reported higher need satisfaction, lower need frustration, higher log-transformed physical activity, greater perceived exercise persistence, higher self-rated PE performance, more favorable perceived change in exercise frequency, and lower daily sitting time. Cross-sectional indirect-association models showed SDT-consistent pathways through increased need satisfaction and/or reduced need frustration. The direction of the primary findings remained consistent in the supplementary sensitivity analyses. Discussion: Platform-supported PE may be understood as a motivational environment rather than merely a technological tool. However, because of non-random allocation, baseline imbalance, reliance on self-report outcomes, absence of complete pretests, and lack of objective individual-level platform usage logs, the findings should be interpreted as post-intervention group differences and cross-sectional associations rather than causal intervention effects.