Peak oxygen uptake in relation to growth and maturation in 11-to 17-year-old humans

This study used multilevel modelling to examine peak oxygen uptake ((V)over dotO(2peak)) during growth and maturation. Body mass, stature, triceps and subscapular skinfold thicknesses, blood haemoglobin concentration, and (V) over dotO(2peak) of boys and girls, [mean (SD)] aged 11.1 (0.4) years at th e onset of the study, were measured at ages 11, 12, 13 and 17 years. Sexual maturation was assessed on the first three occasions and was assumed to be Tanner stage 5 at 17 years. The analysis was founded on 388 (V)over dotO(2 peak) determinations from 132 children. The initial model revealed mass, st ature and age as significant explanatory variables Of (V)over dotO(2peak) w ith an additional positive effect for stage of maturity. Girls' values were significantly lower than those of boys and a significant age-by-sex intera ction described a progressive divergence in boys' and girls' (V)over dotO(2 peak). The introduction of skinfold thicknesses produced a model with an im provement in fit. The stature term was negated and the mass exponent almost doubled. The sex and age-by-sex terms were reduced but remained significan t. Many of the observed maturity effects were explained with stage 5 becomi ng non-significant. Blood haemoglobin concentration was a nonsignificant pa rameter estimate in both models. Fat-free mass was the dominant influence o n the growth Of (V)over dotO(2peak) but the multilevel regression models de monstrated that, with body size and fatness allowed for, (V)over dotO(2peak ) increased with age and maturation in both sexes.