Maximal oxygen uptake versus maximal power output in children

Area of Science:

• Pediatric Exercise Physiology
• Sports Science
• Cardiorespiratory Fitness Assessment

Background:

• Maximal oxygen uptake (VO2max) is the gold standard for aerobic fitness assessment.
• Measuring VO2max requires specialized equipment and trained personnel, limiting its use in large-scale studies.
• Maximal exercise testing to determine maximal power output presents a more accessible alternative.

Purpose of the Study:

• To investigate the relationship between maximal oxygen uptake (VO2max) and maximal power output in children.
• To develop and validate reference equations for estimating VO2max from maximal power output in a pediatric population.
• To assess the utility of maximal power output as a surrogate measure for VO2max in children aged 7.9–11.1 years.

Main Methods:

• Indirect calorimetry was used to measure VO2max during maximal ergometer tests in 247 children (139 boys, 108 girls).
• Maximal power output was recorded concurrently with VO2max measurements.
• Reference equations were derived from one sample (n=124) and validated on a separate sample (n=123).

Main Results:

• A linear reference equation was established: VO2max (ml·min⁻¹) = 96 + 10.6 × maximal power + 3.5 × body mass.
• Estimated VO2max per unit of body mass derived from maximal power output showed a strong correlation (r=0.91, P<0.001) with directly measured VO2max.
• Bland-Altman analysis indicated good agreement, with mean limits of agreement of 0.2 ± 2.9 (ml·min⁻¹·kg⁻¹).

Conclusions:

• Maximal power output is a strong surrogate for VO2max in children aged 8-11 years.
• The derived reference equation provides a valid method for estimating VO2max from maximal power output in population studies.
• This finding simplifies the assessment of aerobic fitness in pediatric research settings.