The purpose of this study was to determine the relationship between VO2max and the 1/2-mile run-walk and the reliability of each in children with mental retardation (MR). Twenty-three children (13 boys, 10 girls) with mild or moderate MR participated in the study. Two maximal treadmill protocols with metabolic measurements and two 1/2-mile run-walk trials were randomly conducted on separate days. There was no difference between Trial 1 and Trial 2 for VO2max (28.2 vs. 29.6 ml · kg−1 · min−1), maximal heart rate (175 vs. 177 bpm), or run-walk time (7.2 vs. 7.1 min). The test-retest correlations were r = .90 for VO2max, r = .81 for maximal heart rate, and r = .96 for the 1/2-mile run-walk (p < .05). The correlation between VO2max and the 1/2-mile run-walk was r = −.60 (p < .05). Adding body mass index to the model improved R to .67 (SEE = 7.3). The 1/2-mile run-walk was a reliable test, but had questionable validity as an indicator of aerobic capacity in children with mild and moderate MR.
Bo Fernhall, Ken Pitetti, Nancy Stubbs and Louis Stadler Jr.
Kenneth H. Pitetti, Bo Fernhall, Nancy Stubbs and Louis V. Stadler Jr.
The purpose of this study was to determine if a step test could be feasible, reliable, and valid for youths with educable (EMR) or trainable (TMR) mental retardation. Thirteen males and 11 females (age M = 14.7 ± 2.7 yr) with EMR or TMR participated in this study. Three step tests were employed using one platform height and stepping frequencies of 13, 15, and 17 ascents/min for 3 min. Recovery HR was used to estimate VO2peak. Though significant, correlations between the recovery HR and VO2peak for the 15 (r = −0.48) and 17 (r = −0.46) ascents/min were not high enough to be considered valid indicators of VO2peak. The large standard errors of the estimate and total errors suggested systematic errors of prediction. Furthermore, the measured VO2peak was significantly different from the estimated values at all step rates (p < .05). The step-test was relatively feasible, but was not a valid test of VO2peak in this population.