Objectives: We examined the association of adolescents' beverage consumption with physical activity and studied how their school beverage environment influences the association.
Methods: We used nationally representative data from the 2007 Early Childhood Longitudinal Study-Kindergarten Cohort (n = 8850). We examined nonlinear associations of eighth graders' self-report of beverage consumption (milk, 100% juices, soft drinks) with moderate to vigorous physical activity and physical education (PE) participation using piecewise linear regression models.
Results: We found a nonlinear association of participation in PE class with beverage consumption, especially in schools with vending machines and those selling soft drinks. For students participating in PE less than 3 days per week, beverage consumption was not significantly associated with participation in PE class frequency. For students participating in PE 3 to 5 days per week, 1 more day of participation in PE class was associated with 0.43 (SE = 0.14; P = .002) more times per week of soft drink consumption and 0.41 (SE = 0.17; P = .021) fewer glasses per week of milk consumption.
Conclusions: The more soft drink and less milk consumption related to high participation in PE class might be prevented by improving the beverage environment in schools. Systematic environmental interventions are needed to prevent such potential unintended consequences of promoting physical activity.