Feasibility and Reliability of Tests Measuring Health-Related Physical Fitness in Children With Moderate to Severe Levels of Intellectual Disability.

Physical fitness is an important marker for health. In this study we investigated the feasibility and reliability of health-related physical fitness tests in children with moderate to severe levels of intellectual disability. Thirty-nine children (2-18 yrs) performed tests for muscular strength and endurance, the modified 6-minute walk test (6mwt) for cardiorespiratory fitness, and body composition tests, and 30-97% of the tests were successfully completed. Short-term test-retest reliability of all tests was good (Intraclass Correlation Coefficient [ICC] > .8), long-term test-retest reliability was good for most tests (ICC > .7), but low ICCs were found for most strength tests. Measuring body composition and cardiorespiratory fitness is feasible and reliable. Measuring muscle endurance is fairly feasible and reliable.