The Relationship Between Social Network Site Appearance Comparison and Exercise Adherence Among Female University Students: A Three-Wave Cross-Lagged Study

This study examined the longitudinal reciprocal associations between social network site appearance comparison and exercise adherence among female university students using a three-wave cross-lagged panel design. A total of 1053 female undergraduates from four universities in Jiangxi Province, China, provided valid baseline data, and 916 of these participants completed all three assessments conducted at approximately three-month intervals and were included in the final analyses. Both constructs were assessed using validated self-report questionnaires, and analyses were conducted using SPSS 26.0 and Mplus 8.3. Social network site appearance comparison was negatively correlated with exercise adherence across waves (r = −0.383 to −0.237, all p < 0.001). Cross-lagged analyses revealed reciprocal negative prospective associations: higher appearance comparison was associated with lower subsequent exercise adherence from T1 to T2 (β = −0.158, p < 0.001) and from T2 to T3 (β = −0.156, p < 0.001), while higher exercise adherence was associated with lower subsequent appearance comparison from T1 to T2 (β = −0.181, p < 0.001) and from T2 to T3 (β = −0.178, p < 0.001). These longitudinal associations did not significantly differ across family residence or academic year groups. The findings indicate reciprocal longitudinal associations between appearance comparison on social network sites and exercise adherence among female university students, highlighting the potential relevance of both constructs to understanding their changes over time.