Cardiovascular Fitness Testing and Fitness Levels of Adolescents and Adults with Mental Retardation Including down Syndrome

Abstract

The purpose of this study was to describe and evaluate the outcome of maximal graded exercise testing of adults and adolescents who are mentally retarded (MR). In addition, the efficacy of maximal testing of subjects with Down Syndrome was evaluated. Twenty-four adults with mental retardation (15 females; 9 males) from a midwest location (mean age = 29.7 yrs.; mean IQ = 52.3) and 14 adolescents with mental retardation and Down Syndrome (11 males; 3 females) from a southern location in the US (mean age = 17.7 yrs.; IQ = 30-70), were recruited for the study. Following familiarization with the testing procedures, all subjects completed a walking treadmill protocol to exhaustion. Metabolic data were collected through open circuit spirometry at both study locations, and one minute averages were calculated. ECGs were obtained using a modified CM₅ electrode system, at rest and every minute during exercise. The mean maximal oxygen uptake (VO₂max) and maximal heart rates (HRmax) of both the adult subjects (25.28 ml·kg⁻¹·min⁻¹ and 174 bpm), and the adolescent subjects with Down Syndrome (26.7 ml·kg⁻¹·min⁻¹ and 171 bpm) were less than expected from their nonretarded peers. This is consistent with previous research which have shown lower than normal cardiovascular fitness levels for persons with mental retardation, and lower than anticipated maximal heart rates. All subjects could safely be exercised to exhaustion, without cardiovascular complications. The subjects with Down Syndrome did not show any cardiovascular abnormalities during exhaustive work, provided they were carefully screened for contraindications to exercise prior to testing. Thus, persons with Down Syndrome can safely participate in rigorous exercise programs provided they are prescreened for exercise contraindications, and carefully supervised.