Physical exercise promotes prosocial behavior in college students through a chain mediation of peer relationships and positive empathy.

Grounded in the person-context interaction theory, this study aimed to investigate the relationship between physical exercise and prosocial behavior among college students, with a specific focus on examining the parallel and chain mediating roles of peer relationships and positive empathy within this relationship. A convenience sampling method was employed. Surveys were conducted using the Physical Activity Rating Scale, the Prosocial Tendencies Measure, the Peer Rating Scale, and the Positive Empathy Scale among undergraduate students from five universities in China. A total of 991 valid questionnaires were collected. (1) Significant positive correlations were observed between physical exercise, prosocial behavior, peer relationships, and positive empathy. (2) Regression analysis and mediation effect tests revealed that physical exercise not only directly and positively predicted college students’ prosocial behavior but also exerted significant influence through three indirect pathways: first, through the independent mediating role of peer relationships; second, through the independent mediating role of positive empathy; and third, through a chain mediating pathway involving peer relationships followed by positive empathy. This study demonstrates that physical exercise promotes prosocial behavior in college students by enhancing the quality of peer relationships and fostering positive empathy. This mechanism indicates that physical exercise contributes to the cultivation of a positive interpersonal environment, thereby building social capital, while simultaneously facilitating the development of internal emotional competencies, or psychological capital. These findings hold significant practical value for promoting college students’ physical and mental health, nurturing their sense of social responsibility, and contributing to a harmonious society.