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
