Influence of anthropometric characteristics on changes in maximal exercise ventilation and breathing pattern during growth in boys

Summary The aim of this study was to investigate the effect of growth on ventilation and breathing pattern during maximal exercise oxygen consumption (VO_2max and their relationships with anthropometric characteristics. Seventy six untrained schoolboys, aged 10.5–15.5 years, participated in this study. Anthropometric measurements made included body mass, height, armspan, lean body mass, and body surface area. During an incremental exercise test, maximal ventilation (V_Emax), tidal volume (V_Tmax), breathing frequency (f_max), inspiratory and expiratory times (t_Imax and t_Emax), total duration of respiratory cycle (t_TOTmax), mean inspiratory flow (V_T/t_Imax), and inspiration fraction (t_I/t_TOTmax) were measured at VO_2max. A power function was calculated between anthropometric characteristics and ventilatory variables to determine the allometric constants. The results showed firstly, that V_Emax, V_Tmax, t_Imax, t_Emax, t_TOTmax, and V_T/t_Imax increased with age and anthropometric characteristics (P<0.001), f_max decreased (P<0.001), and t_I/t_TOTmax remained constant during growth; secondly that lean body mass explained the greatest percentage of variance of V_Emax (62.1%), V_Tmax (76.8%), and V_T/t_Imax (70.6%), while anthropometric characteristics explained a slight percentage of variance of f_max and timing; and thirdly that V_Emax, V_Tmax, and V_T/t_Imax normalized by lean body mass did not change significantly with age. We concluded that at VO_2max there were marked changes in ventilation and breathing pattern with growth. The changes in V_Emax, V_Tmax, and V_T/t_Imax were strongly related to the changes in lean body mass.