Physical exercise and externalizing problem behavior of junior middle school students: Peer relationships and self-esteem as chain mediators

In this study we examined the relationship between physical exercise and externalizing problem behavior and further analyzed the mediating effect of peer relationships and self-esteem on this link. Our sample comprised 1,292 junior middle school students recruited via stratified cluster random sampling. We assessed physical exercise, peer relationships, self-esteem, and externalizing problem behavior by using standardized scales. The results showed that physical exercise had a significant negative correlation with externalizing problem behavior, and that peer relationships and self-esteem had both independent and chain mediating effects on this link. Our findings provide a theoretical basis for designing interventions to address externalizing problem behavior in junior high school students.