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.