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 (VO_2PEAK) 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. VO_2PEAK 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 VO_2PEAK (mL/min), VO_2PEAK scaled by body weight (mL/min/kg) and VO_2PEAK by allometric scaling (mL/min/kg^0.71), whereas no relationships were detected for VO_2PEAK scaled to fat‐free mass (FFM) (mL/min/FFM). Person correlation coefficients for boys were 0.26, ?0.38, ?0.19 and ?0.01 NS and for girls 0.33, ?0.42, ?0.21 and ?0.03 NS, respectively. Significant differences in VO_2PEAK existed between different quartiles of BF%, with the exception when VO_2PEAK 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 VO_2PEAK was scaled to FFM represents a body fat independent way of expressing fitness.