Breaking the cycle: how physical activity disrupts repetitive negative thinking in adolescents through positive affect and cognitive flexibility.

Repetitive negative thinking is a transdiagnostic cognitive process that is particularly prevalent during adolescence, a developmental period characterized by rapid changes in emotional regulation and executive control. Repetitive negative thinking is closely associated with a range of internalizing problems and represents an important risk factor for adolescent depression and anxiety. Given that academic pressure and self-focused attention increase markedly during the high school stage (ages 15–17), repetitive negative thinking is more likely to be activated and maintained during this period; therefore, the present study focused specifically on adolescents within this age range. Existing evidence suggests that physical activity is associated with repetitive negative thinking; however, the emotional and cognitive mechanisms underlying this association remain unclear. The present study aimed to examine the mediating roles of positive affect and cognitive flexibility in the association between physical activity and repetitive negative thinking. Both mediators were simultaneously incorporated into a single structural equation modeling (SEM) framework to estimate their parallel indirect effects as well as their serial indirect effect, and competing models were further tested to evaluate the robustness of the findings. A total of 1,023 adolescents were included in the statistical analyses (525 males and 498 females; age 15: n = 348, age 16: n = 343, age 17: n = 332; M = 15.98, SD = 0.82). Based on self-reported cross-sectional data, descriptive statistics and correlation analyses were conducted using SPSS. The hypothesized serial mediation model was examined using structural equation modeling combined with bias-corrected bootstrapping (5,000 resamples). Subsequently, PROCESS was used to test competing models, including a parallel mediation model and a reversed serial mediation model, as robustness checks. The results indicated that physical activity was positively associated with positive affect and cognitive flexibility, and negatively associated with repetitive negative thinking. Both positive affect and cognitive flexibility were negatively associated with repetitive negative thinking, and positive affect was positively associated with cognitive flexibility. Given the cross-sectional design, these findings should be interpreted primarily as evidence of statistical associations and model-based pathways rather than indications of temporal precedence or causal direction. Future research may adopt longitudinal or experimental designs and incorporate objective measures of physical activity to further examine these associations under different temporal orderings.