The impact of physical activity on adolescent social anxiety: a growth curve model analysis

Objective This study examined the dynamic association between adolescents’ physical activity levels and social anxiety using a latent growth curve model. Methods A longitudinal survey was conducted with 851 students from five middle schools in Sichuan, Jiangsu, and Guangdong provinces, China. Assessments were conducted at 3-month intervals. Physical activity and social anxiety were measured using the IPAQ and the Social Anxiety Scale for Adolescents. Latent growth curve models were estimated using Mplus 8.0. Results (1) Physical activity followed a nonlinear trend, initially decreasing and then increasing (initial level = 3.267, p < 0.01; linear rate = −0.087, p < 0.01; nonlinear rate = 0.026, p < 0.01). (2) Social anxiety showed an “increase-then-decrease” trajectory (initial level = 2.713, p < 0.01; linear rate = 0.178, p < 0.01; nonlinear rate = −0.064, p < 0.01). (3) The initial level of physical activity negatively predicted social anxiety’s initial level (β = −0.250, p < 0.001) and change rate (β = −0.154, p < 0.001). Conclusion Higher physical activity levels were associated with lower social anxiety and slower increases in social anxiety over time. Promoting regular physical activity may help support adolescent mental health.