Effects of physical activity on depression and physical fitness among Shanghai junior high school students

This study explores the relationship between light physical activity (LPA) and moderate-vigorous physical activity (MVPA), depression and physical fitness among Shanghai junior high school students. A nationwide offline survey was conducted in Shanghai between August and December 2023 using a purposive sampling design. A total of 432 questionnaires were administered to six seventh-grade classes and eighth-grade classes from six schools in Shanghai; 416 responses were included in the final analysis. SPSS software version 29, the Correlation and Multiple Linear Regression techniques were employed to analyze the collected data. Higher levels of LPA and MVPA were correlated with lower levels of depression. However, only LPA was a significant positive predictor for depression among Shanghai junior high school students. MVPA did not show significant predictive power for depression. Only MVPA was positively correlated with 50 meters (50M), standing long jump (SLJ), 800/1000 meters (800/1000M), and total physical fitness (TPF), but not for sitting forward bend (FB) and vital capacity (VC); various measures of physical fitness were found highly correlated with each other. MVPA was also a significant positive predictor for 800/1000M, SLJ, 50M and TPF but not for VC and FB. LPA did not show significant predictive power for any physical fitness measures. The findings highlighted the importance of MVPA in enhancing physical fitness outcomes, while LPA primarily impacted depression levels. Various measures of physical fitness were highly interrelated. The results underscored the significance of promoting MVPA to improve physical fitness and reduce depressive symptoms in this population.