Vigorous physical activity and low-grade systemic inflammation in adolescent boys and girls

Purpose. The association between physical activity (PA) and inflammation has been established in adults, yet little is known about this relationship in youth. This study examined the relationship between vigorous PA and C-reactive protein (CRP) in adolescents. Methods. Data were available for 1 520 adolescents, aged 13 and 16 years, in a province-wide survey of a representative sample of youth in Quebec, Canada. Participants completed questionnaires assessing VPA, pubertal stage, body image, and health problems; they provided a fasting blood sample for CRP; and they had height and weight measured. Results. In sex-specific multivariable logistic regression models, VPA was protective of elevated CRP in boys (OR=0.60, 95%CI=0.37-0.99) independent of weight status, pubertal stage, anti-inflammatory/antibiotic medication, and smoking. CRP and physical activity were not related in girls (OR=1.12, 95%CI=0.69-1.82). Conclusions. In addition to many known health benefits of VPA, the current findings provide evidence that VPA may protect against low-grade systemic inflammation in boys. These data provide further support for the importance of promoting healthy PA levels in youth.