Physical activity and a dual measure of body composition are independently related to cardiorespiratory fitness in U.S. adolescents
Peter D Hart
Background: Abdominal fat is a less known correlate of health-related fitness in adolescents.
Aim: The purpose of this study was to investigate the influence that physical activity (PA) and a dual measure of body composition (BC) have on cardiorespiratory fitness (CRF) in U.S. adolescents.
Methods: Data were used from the 2012 NHANES National Youth Fitness Survey (NNYFS) and included youth aged 12 to 15 years. Four different measures of PA were used: moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous-PA (MVPA), and number of days per week physically active for 60+ minutes (D60Min). Body mass index (BMI) and waist circumference (WC) were used as BC measures and maximal oxygen consumption (VO2max) used as the measure of CRF. Binary variables of “high” and “low” were created for the PA, BC, and CRF variables. A final binary BC variable (BMI.WC) was created to indicate “high” on both BMI and WC.
Results: Fully adjusted models showed a significant increased odds of low CRF for adolescents with low VPA (OR = 2.47, 95% CI: 1.86-3.29), low MVPA (OR = 2.48, 95% CI: 1.59-3.86), and low D60Min (OR = 1.50, 95% CI: 1.00-2.25). MPA was not significantly related to CRF. In all four PA models, odds of low CRF were almost three times greater in adolescents with high BMI.WC.
Conclusion: This study showed that PA and a dual measure of BC independently predict CRF in U.S. adolescents. With the exception of MPA, which was not related to CRF in these youth.