Changes in oxygen consumption of young boys during growth and running training

Abstract

Fourteen boys, aged 10–15, were tested on five occasions during 22 months of distance-running training. Semi-annually, height and weight were recorded as were performances for 1− and 2-mile races. Sub-maximal and maxV̇o₂ were also determined from expired gas samples which were collected during treadmill running. After 22 months, average growth was 11.2 cm and 9.2 kg. MaxV̇o₃ increased from 2331 ml to 2839 ml; maxV̇o₂/kg did not change significantly from a mean of 59.5 ml/kg per minute. During the 12-month period of greatest growth (6.4 cm and 5.9 kg), maxV̇o₂ increased 295 ml, a. 50 ml increase per kg increase in weight. Again no change was measured in maxV̇o₂/kg. Average improvement in running performance was 32 seconds in the mile and 63 seconds in 2 miles. Steady-state Vo₂ (ml/kg per min) during running at 202 m/min gradually diminished from 52.0 in the initial test series to 45.5 22 months later. This apparent improvement in running efficiency, which was to a great degree a function of growth, was believed to be (along with possible increased anaerobic activity) mainly responsible for better running performance.