Concepedia

Abstract

Little is known regarding the physiological determinants of maximal oxygen uptake (VO 2 max) in children. A group of 39 healthy sixth-grade boys (mean age, 12.2 years) underwent maximal cycle testing with determination of cardiovascular factors using Doppler echocardiography as well as standard gas exchange variables. Maximal stroke index was related to VO 2 max/kg ( r =0.52, p < .05), but no relationship was observed between VO 2 max/kg and either maximal heart rate or calculated maximal arteriovenous oxygen difference. Values of maximal stroke index were closely related to those at rest ( r = 0.67). These findings suggest that factors influencing resting stroke volume are primarily responsible for inter-individual differences in VO 2 max per kg in healthy, non-athletically-trained boys.