This study evaluated the concurrent validity of the 300-yard and the 1.5-mile run with a group of mildly mentally retarded (MR) adults. The subjects, 15 healthy MR adults (M age = 29.5 + 5.6 yrs, M IQ = 60), underwent a maximal treadmill test utilizing a walking protocol, with heart rate and oxygen consumption data collected every minute. They also completed a 300-yard and a 1.5-mile run. The order of testing was counterbalanced. The results indicated that these subjects exhibited very poor cardiovascular fitness levels, with a mean V̇O2max of 28.1 ml•kg-1•min-1 and mean run times of 98.9 sec and 21.1 min for the 300-yard and the 1.5-mile runs, respectively. The correlation between V̇O2max and the 1.5-mile run was –.88, and the correlation for the 300-yard run and V̇O2max was –.71. However, partial correlations indicated that when the effect of height and weight were held constant, only the correlation between V̇O2max and the 1.5-mile run remained significant whereas that between V̇O2max and the 300-yard run dropped. Consequently, the 1.5-mile run appears to be a valid indicator of cardiovascular fitness for these adults with MR, but the 300 yard run is not.
Bo Fernhall and Garth T. Tymeson
Bo Fernhall, Garth T. Tymeson and Gail E. Webster
This manuscript critically reviews the literature on cardiovascular fitness (CVF) and the mentally retarded (MR) individual. For the purposes of this review, no distinction is made between maximal aerobic capacity, maximal physical work capacity, CVF, and cardiovascular endurance. Several large-scale field studies have been conducted with MR children, and all have generally found low CVF levels for this group. However, these field tests have not been validated with MR individuals, thus this conclusion may be incorrect. Smaller field studies with MR adults and adolescents show similar results, but also exhibit the same problem of nonvalidation of the field tests used. Better evidence for low levels of CVF is exhibited through several well conducted laboratory studies, with measurements of V̇O2 max. In general, MR individuals, regardless of age, possess CVF levels 20-40% below those of their nonretarded peers. It is hypothesized that this is due to inactivity, but there still is the possibility of a retardation-dependent physiological difference. MR children and adults appear to respond in a normal manner to CVF training, but the threshold of training required is undetermined. MR adolescents have not shown reliable increases in CVF with training, although it is not known why. Several suggestions are made regarding the need for future research.