Associations of social avoidance and sport engagement with physical health indicators among schoolchildren: a cross-sectional study.

Background: This study examined cross-sectional associations of social avoidance with sport engagement and of sport engagement with physical health indicators among schoolchildren. Potential nonlinear associations were also assessed. Exploratory latent profile analysis (LPA) examined whether cognitive, affective, and relational engagement provided information beyond the continuous total engagement score. Methods: This cross-sectional study included 923 students in Grades 3-5 from one Beijing school. Questionnaires assessed social avoidance and sport engagement across sport settings. Routine school records provided physical fitness, height, and weight, from which a BMI-excluded physical fitness score was calculated. Classroom-clustered linear and logistic regression models examined associations of social avoidance with total sport engagement and of sport engagement with BMI-excluded physical fitness, BMI, and overweight/obesity. Models adjusted for sex, grade, school-based sport participation, and out-of-school sport participation. Holm correction was applied to four focal associations and four corresponding quadratic tests. LPA was exploratory and accounted for classroom clustering. Results: The adjusted regression analyses included 913 students. Higher social avoidance was associated with lower total sport engagement ( Conclusion: Higher social avoidance co-occurred with lower sport engagement, whereas higher sport engagement co-occurred with higher BMI-excluded physical fitness, lower BMI, and lower odds of overweight/obesity. These associations were small to modest and do not establish temporal or causal relationships. The exploratory classes primarily represented ordered levels along a general engagement continuum and did not support profile-based risk classification.