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.