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.
B. Fernhall is with the Exercise Science Programs, School of Medicine and Health Sciences at The George Washington University, 817 23rd St. NW, Washington, DC 20052. K. Pitetti, N. Stubbs, and L. Stadler, Jr., are with the School of Health Science at Wichita State University, Wichita, KS 67260-0043.