Aerobic fitness in prepubertal children according to level of body fat

Aim: The purpose of this study was to investigate the relationship between maximum oxygen uptake (VO2PEAK) and body fat in young children on a population-based level.Methods: Participants were 586 children (311 boys and 275 girls) aged 6.8 ± 0.4 years, recruited from a population-based cohort. VO2PEAK was measured by indirect calorimetry during a maximal exercise test. Percent body fat (BF%) was estimated from skinfold measurements.Results: Significant relationships existed between BF% and absolute values of VO2PEAK (mL/min), VO2PEAK scaled by body weight (mL/min/kg) and VO2PEAK by allometric scaling (mL/min/kg0.71), whereas no relationships were detected for VO2PEAK scaled to fat-free mass (FFM) (mL/min/FFM). Person correlation coefficients for boys were 0.26, [minus]0.38, [minus]0.19 and [minus]0.01 NS and for girls 0.33, [minus]0.42, [minus]0.21 and [minus]0.03 NS, respectively. Significant differences in VO2PEAK existed between different quartiles of BF%, with the exception when VO2PEAK was scaled to FFM.Conclusion: Our findings document the coexistence of two known risk factors for disease at a young age on a population-base and confirms that VO2PEAK was scaled to FFM represents a body fat independent way of expressing fitness.