Validity of a cardiorespiratory fitness test for men with mental retardation

The purpose of this study was to validate a field test of cardiorespiratory fitness for men with mental retardation. The subjects were 19 healthy young men (26 +/- 6 yr) with moderate mental retardation (IQ = 48 +/- 11). Each subject underwent a maximal treadmill test after a three-phase familiarization process. Each subject also completed a 1-mile walk test twice (Rockport Fitness Walking Test = RFWT). The correlation coefficients between peak VO2 on the treadmill and the two 1-mile walks varied from 0.78 to 0.83. When weight, height, age, heart rates of 1-mile walks, and their combinations were held constant, the correlations were strengthened. Using multiple correlation analysis the best equation for predicting peak VO2 was: Peak VO2 = 101.92 - 2.356(mile-1 time) - 0.42(weight). This model accounted for 85% of total variance. The standard error of estimate was 4.06 ml.kg-1.min-1. The test-retest reliability of the RFWT for the 19 subjects used in this study was very high (R = 0.97). This finding suggests that the RFWT is a valid and reliable field test for this population and appears to be a valid indicator of cardiorespiratory fitness for these men with mental retardation.