Feasibility Of High Intensity Functional Training For Young Adults With Intellectual And Developmental Disabilities

PURPOSE: Physical function may be especially important for young adults with intellectual and developmental disabilities (ID) as they transition to adulthood, where employment frequently depends on physical rather than cognitive capacity. This single arm 12-wk pilot trial evaluated feasibility of a high intensity functional training (HIFT) intervention, which incorporated multimodal, multi-joint movements using body weight and/or external resistance simultaneously targeting cardiovascular and muscular fitness, in a sample of young adults with ID. METHODS: Young adults with ID (n = 21, age ~ 22 yrs., BMI = 29.3 kg/m2, 67% female, 43% non-Hispanic white, 57% Down syndrome) attended 1x/wk. in-person group HIFT sessions (~5 participants) in conjunction with an education intervention designed to improve diet quality and cooking skills. HIFT sessions (~ 45 min) were led by staff experienced in exercise interventions for individuals with ID and included movements mimicking activities of daily living (pushing, pulling, hinging, etc.) using medicine balls, kettle bells, etc. in addition to body weight as resistance. Outcomes included participant retention, session attendance adherence, session enjoyment (self-report via semi-structured interviews), and physical function measures at pre and post, including lower body strength (5-RM to fatigue, plate loaded leg press), handgrip strength (electronic dynamometer) and power, speed, and agility (Timed 8-foot Up and Go). RESULTS: Twenty participants (95%) completed the 12-week intervention. Participants attended 86.5% of HIFT sessions and 100% reported enjoying the HIFT sessions during the structured interviews. Changes in physical function measures included a significant improvement in lower body strength (+11.4 ± 16.2 kg, +20%, p < 0.01), and non-significant improvements in dominant handgrip (+0.3 ± 2.8 kg, +1.5%, p > 0.05), non-dominant handgrip (+1.3 ± 2.9 kg, +7%, p > 0.05) power, speed, and agility (-0.1 ± 1.3 sec, 1.7%, p > 0.05). CONCLUSIONS: HIFT may be a feasible and potentially effective strategy of improving physical function in young adults with ID. Adequately powered trials to further investigate the effectiveness of HIFT for improving physical function and the transition to adulthood in young adults with ID are warranted. Supported by the Human Energy Balance Core at the University of Kansas Center for Metabolism and Obesity Research (NIH P20GM144269) and the Center for Children's Healthy Lifestyles and Nutrition at Children's Mercy Hospital, Kansas City, MO.