Physiologic and anthropometric factors underlying endurance performance in children.

This study investigated the relationship between endurance performance and several measures of aerobic, anaerobic, and morphological fitness in 30 girls and 28 boys, 10 to 14 years of age. A multistage treadmill test was used for assessment of VO2 max (ml X kg-1 X min-1) and anaerobic threshold (AT) expressed both in absolute (AT-VO2) and relative (% VO2 max) terms. Anaerobic capacity (AC) was measured in a 30-s cycling task and expressed as kpm . kg of body weight-1 X min-1. Percent fat was estimated from skinfolds. The correlations between these measures and 2-km run time were: -0.73, -0.73, -0.50, -0.77, and 0.55 for VO2 max, AT-VO2, AT-%VO2 max, AC, and percent fat, respectively. When entered into a forward selection multiple regression with run time as the dependent variable, AC accounted for 59.5% of the variance and VO2 max accounted for an additional 6.9%, with AT and percent fat making no significant additional contribution. When the girls and boys were compared, no reliable differences were found for run time and AC. The boys exhibited reliably higher values for VO2 max and AT-VO2. No reliable difference in percent fat was found for the younger boys and girls, but the older girls were significantly fatter than the older boys. Thus, in children 10 to 14 there is a substantial relation between measures of anaerobic and aerobic function, although to some extent they provide independent information about endurance performance.(ABSTRACT TRUNCATED AT 250 WORDS)