The purpose of this study was to determine how participation in school sport clubs affected academic stress and physical self-efficacy of middle school students. Students at three middle schools in A City and B Province―615 boys and 607 girls―who participated in school sport clubs were sampled. The academic stress scale was the questionnaire reconstructed by Ghang (2013) and the scale developed by Seok (2013) was used to measure physical self-efficacy.
For data processing, frequency analysis, reliability analysis (Cronbach’s α), factor analysis, independent-sample t-test, multi-variate ANOVA, correlation analysis, and post-hoc analysis were performed. There were significant differences in academic stress (expectation, inner world, and expression) and in physical self-efficacy (running, participation in exercise, body type, and appearance) by gender of middle school students participating in school sport clubs. No significant difference was found in physical self-efficacy (muscular strength) by gender. No significant difference was found in academic stress by school year; however, there were significant differences in physical self-efficacy (participation in exercise) by school year. There were significant differences in academic stress (expectation and inner world) and in physical self-efficacy (running, participation in exercise, body type, and appearance) by events. No significant difference was found in academic stress by the duration of participation; however, there were significant differences in self-efficacy (participation in exercise) by the duration of participation. There were significant differences in academic stress (expectation, inner world, and expression) and in physical self-efficacy (running, participation in exercise, body type, and appearance) by frequency of participation. No significant difference was found in physical self-efficacy (muscular strength) by frequency of participation. There were significant differences both in academic stress and in physical self-efficacy by preference for the physical education class. There were significant differences in academic stress (inner world and expression) and in physical self-efficacy (running, participation in exercise, body type, and appearance) by preferred subjects. By the experience of doing exercise or by the duration of participation, no significant difference was found in academic stress; however, there were significant differences in physical self-efficacy. To put these results together, school sport clubs positively affected academic stress and physical self-efficacy of middle school students, depending on the personal background variables.