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

Wouters et al. (2017) asked if regular fitness tests work for kids with moderate to severe intellectual disability. They tried the six-minute walk test, body-fat checks, and other clinic tools. A small group of children completed each test twice within one week.

Every test was doable. Kids finished the tasks without distress. Scores stayed almost the same across the two visits, showing good short-term reliability.

Capio et al. (2013) ran a similar check on older adults with ID. They also found most tests feasible, but adults with profound ID or wheelchair users struggled with leg-based items. The new child data extend that message downward: when you test kids early, even those with severe ID can complete the same tools.

Oppewal et al. (2013) reviewed cardio tests and warned that field scores are shaky predictors of VO2max. Marieke’s team did not chase VO2max; they simply showed the walk test gives steady numbers session-to-session. The papers sit together: use the walk for tracking, not for precise oxygen estimates.

Schertz et al. (2016) later showed excellent reliability in adults with Down syndrome. Marieke et al. now give the child-sized mirror: if the test is stable in adults, it is also stable in children with broader ID.

You can pull standard tools off the shelf and use them right away. No need to invent new kits. Run the six-minute walk, grip test, or body-comp check at intake and again after therapy blocks. Steady numbers let you prove real change instead of measurement noise.