How does fitness-related social media use influences exercise intention? A moderated mediation model within the Theory of Planned Behavior framework

The psychological mechanisms through which fitness-related social media use (FRSMU) influences exercise intention remain insufficiently understood. To address this gap, this study constructed a moderated mediation model based on the Theory of Planned Behavior to systematically examine the underlying mechanisms linking FRSMU and exercise intention. Specifically, this study reveals the mediating roles of attitude and subjective norms in this relationship, and the moderating effect of perceived behavioral control on these mediated pathways. A survey was conducted among 679 university students, utilizing scales measuring FRSMU, exercise attitude, subjective norms, perceived behavioral control, and exercise intention. Data analysis was performed using Mplus software through bootstrapping and the latent moderated structural equation modeling approach. The results showed that: (1) FRSMU significantly and positively predicted exercise intention; (2) Attitude mediated the relationship between FRSMU and exercise intention, while the mediating effect of subjective norms was not supported; (3) Perceived behavioral control exerted a significant negative moderating effect on the mediation pathway from FRSMU to exercise intention via attitude, while it had a significant positive moderating effect on the indirect pathway from FRSMU to exercise intention through subjective norms. These findings provide valuable insights for designing interventions aimed at promoting university students' exercise behavior through social media.