Cardiovascular fitness of mentally retarded individuals

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 now known why. Several suggestions are made regarding the need for future research.