The Relationship Between Physical Activity and Depression Among Middle-Aged and Elderly Chinese: A Longitudinal Study.

This study aimed to explore the association between physical activity and depression risk among middle-aged and elderly Chinese using both cross-sectional and longitudinal data. A total of 3564 participants from the China Health and Retirement Longitudinal Study (CHARLS) were included. The cross-sectional analysis of 2020 data revealed a U-shaped dose-response relationship between physical activity levels and depression risk. Longitudinally, group-based trajectory modeling identified five distinct physical activity patterns from 2011 to 2020. Compared to the low-stable group, the moderate-stable group showed a 47% reduced risk of depression, while the highest-stable group had a 37% increased risk. Gender-stratified analyses showed that long-term moderate physical activity had protective effects in both males and females, whereas excessive activity was only associated with higher depression risk in females. These findings suggest that physical activity can serve as both a protective and risk factor for depression, with gender-specific considerations in older adults.