Aerobic capacity as related to leg strength in youths with mental retardation

The purpose of this study was to evaluate the relationship between aerobic capacity (VO(2)peak) and leg strength of male (n = 17) and female (n = 12) youths (age = 14.2 +/- 2.1 years) with mild to moderate mental retardation. Aerobic capacity was determined by a treadmill test (GXT) and isokinetic knee flexion and extension strength (peak torque, peak force, average force) was determined by isokinetic dynamometry. Results indicate that significant positive relationships (p <.05) exist between VO(2)peak (ml.min(-1).kg(-1)) and isokinetic leg strength expressed relative to body weight. The results indicate that leg strength is a contributor to aerobic fitness in youths with mental retardation. Additionally, when considering the low levels of both strength and VO(2)peak, leg strength may be a limiting factor of VO(2)peak in these youths, or the relationship may be explained by the concept of metabolic nonspecialization.