ENDURANCE TRAINING AND VO2MAX IN CHILDREN: A META-ANALYSIS

Abstract

864 Numerous investigations and reviews have attempted to determine the effects of physical training on maximal oxygen consumption (VO2max) in children and youth. This study was conducted to quantitatively examine this question using the meta-analytic technique. We examined the effects of physical activity, training protocol, gender and experimental design on the VO2max of children. Five separate computer searches were initially conducted with all references being cross-checked for additional sources. References were delimited to those studies examining the effects of various forms of muscular strength and endurance training. Only data from subjects< 18 years were used for analyses. Ninety-four studies were initially reviewed. Numerous studies failed to provide sufficient information (grouped ages, combined genders, poor description, etc.) or adequate statistics (means, standard deviations, sample sizes). This resulted in 50 effect sizes (ES) from 20 studies. (11 ESs were eliminated because they were > 3.0sd above the ESs). The mean ES for girls and boys was 0.71 ± 0.44 and 0.22 ± 0.87, respectively. These data indicate the potential for significant trainability for female subjects. Although the mean ES revealed a considerable difference between trained and untrained subjects, possible confounding sources in cross-sectional designs (XS) were noted. The mean ES of 0.89± 0.68 and 0.47 ± 0.77 were computed for XS and pretest-posttest(PP) designs, respectively. Additional analyses revealed that subjects improved 2.9 ml·kg-1·min-1 in studies utilizing a PP design. Furthermore, in PP studies the ESs were not affected by training protocol or gender. The results of this quantitative review indicate that reported changes in VO2max in children are modest and largely a function of the experimental design of the investigation.