Submaximal Aerobic Running Economy and Treadmill Performance in Prepubertal Boys

Abstract

Although the determinants of running economy and its relationship to endurance performance have been evaluated in adults, little data are available in pediatric subjects. Twenty-eight prepubertal boys with diverse athletic abilities underwent progressive maximal treadmill testing. Running economy was defined as (1) V̇O₂ at 9.6 kph and (2) V̇O₂ expenditure for increasing running speed 1.6 kph (delta V̇O₂). Treadmill running times ranged from 12.6 to 23.0 min. Mean V̇O₂ at 6 mph was 48.7m·kg^-1·min^-1 (SD 4.3) and delta V̇O₂ averaged 6.8 m·kg^-1·min^-1 (SD1.7). V̇O₂max correlated closely to treadmill time. Treadmill endurance times were significantly reltated to running economy by both definitions; submaximal V̇O₂ levels did not, however, correlate with maximal aerobic power. Delta V̇O₂ was associated with stride frequency, but no other relationships were observed between economy and height, age, respiratory exchange ratio, ventilatory equivalent for oxygen, stride length: leg length ratio, or body surface area: mass ratio. These findings suggest that among older prepubertal boys, greater running economy is associated with superior treadmill endurance performance and that stride frequency may influence submaximal V̇O₂ expenditure in children.

Key words

aerobic running economy - treadmill performance - prepubertal boys