Maximal aerobic power affected by maturation and body growth during childhood and adolescence

This paper examines the development of maximal aerobic power as a function of maturation by a longitudinal study with annual examinations of representative samples of 56 boys and 56 girls in Norway and Western Germany. The age at which occurred peak height velocity (PHV) (i.e. the age at which the greatest height velocity was observed) was used as a reference of biological age and maturation. Before the PHV the mean maximal aerobic power was the same in two cohorts of children both in absolute values as well as in values relative to total and lean body mass. At and after PHV the boys were similar in their absolute values, but the German girls decreased their exercise fitness and became inferior to the Norwegian girls during later adolescence. When related to age of PHV the maximal aerobic power increased during the prepubertal years, mainly as an effect of growth in body size with little or no additional effect of other factors and approached a ceiling level at the end of adolescence. The boys exhibited clearly superior exercise fitness during all years of childhood and adolescence, this being in contrast to the widely accepted concept that no sex difference exists in exercise fitness before puberty. The maximum level for VO2-max, reached at the end of adolescence, averaged 3.2 1/min with a coefficient of variation of about 12% for the boys, and 2.5 1/min for the Norwegian girls and a similar coefficient of variation. As these ceiling values of maximal oxygen uptake agree with published averages for normal young adults representative for the normal population in these two countries, it is suggested that they represent optimal values brought about mainly by normal growth in body size with no or little additional effects of other factors.