Predicting aerobic power in children. A comparison of two methods.

OBJECTIVE: To compare the accuracy of two equations for predicting VO2max of children using submaximal cycle ergometry. EXPERIMENTAL
DESIGN: Repeated measures comparing treadmill measured maximal aerobic power (VO2max) with two methods of predicting VO2max using cycle ergometry testing. PARTICIPANTS: Thirty-three children (15 boys and 18 girls) aged 7-13 years served as subjects. MEASURES: Each child completed a treadmill graded exercise test (GXT) to volitional fatigue to assess VO2max. Each child also completed a progressive 9-min, three-stage, submaximal cycle ergometer test. Heart rates obtained during the last minute of each stage of the ergometer test were used to predict VO2max. Predictions were based on a gender-specific modification of the PWC170 (PWCGS) and a modification of the PWC195 using a 1.17 correction factor and an age and gender-adjusted estimate of resting metabolic rate.
RESULTS: The correlations between both submaximal tests and the GXT were significant (p < 0.001); however, the correlation between the GXT and the PWC195 equation (r = 0.807) was higher than the correlation between the GXT and the PWCGS equation (r = 0.658). Analysis indicated that the PWCGS equation significantly underestimated the VO2max compared to either the GXT or PWC195 (GXT = 45.0 +/- 7.1, PWC195 = 44.7 +/- 6.2, PWCGS = 42.7 +/- 5.8 ml/kg/min; p < 0.01).
CONCLUSIONS: These results suggest that although the gender-specific PWCGS method is easier to compute and may be acceptable, the modified PWC195 method is a more accurate estimate of VO2max in children.