Exercise and VO2 max in children: a meta-analysis

Area of Science:

• Pediatric Exercise Science
• Sports Medicine
• Human Physiology

Background:

• Aerobic trainability in children is widely believed but inconsistently demonstrated.
• Maximal oxygen uptake (VO2max) is a key indicator of aerobic fitness.
• Previous research on VO2max changes in children has produced conflicting results.

Purpose of the Study:

• To meta-analytically examine factors influencing VO2max improvements in children.
• To investigate the impact of physical activity, gender, and experimental design on children's aerobic capacity.
• To assess the effect of training sufficiency on VO2max changes in pediatric subjects.

Main Methods:

• A meta-analysis was performed on 28 studies involving 70 effect sizes related to children's VO2max.
• Studies were categorized by experimental design: cross-sectional (XS) and pretest-posttest (PP).
• Further analysis focused on PP studies to evaluate training effects, gender, and protocol sufficiency.

Main Results:

• Cross-sectional designs (XS) showed larger effect sizes (.94) compared to pretest-posttest designs (PP) (.35), potentially due to confounding factors like self-selection.
• In PP designs, children improved VO2max by approximately 2 ml.kg-1.min-1.
• Effect sizes in PP studies were not significantly influenced by gender, training sufficiency, or test mode.

Conclusions:

• Reported changes in children's VO2max are generally small to moderate.
• The observed magnitude of VO2max change is significantly dependent on the experimental design employed.
• While children show some aerobic improvement, the interpretation of training effects requires careful consideration of study methodology.