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Do individuals with intellectual disabilities have an abnormal physiological response to exercise?

Periodic Report Summary 1 - ID PHYSIOLOGY (Do individuals with intellectual disabilities have an abnormal physiological response to exercise?)

Individuals with intellectual disabilities (ID) are important consumers of health care, partly due to high prevalence rates of inactivity-related health conditions. So far, adapted physical activity interventions have focused mostly on organizational and behavioral aspects, with disappointing results. In these studies, physiological aspects such as cardiorespiratory capacity or energy cost of activities, were not taken into account or were assumed to be similar to the general population. However, abnormalities in the autonomic response to exercise and higher energy cost of activities have been demonstrated in small and selected samples of the ID population, mostly in people with Down syndrome. The aim of this research proposal was therefore to investigate physiological barriers that influence physical activity and exercise in people with ID. Risks of not knowing about these barriers are fatigue, injury and lack of motivation of people with ID, in a vicious circle leading to loss of functioning and health conditions.

During the outgoing first phase, I studied (abnormalities in) the autonomic cardiorespiratory response of people with ID, using different sympatho-excitatory tasks.
The hypothesis for the research study in this year was: the maximal cardiorespiratory capacity of people with intellectual disabilities (ID) is lower than that of a control group without intellectual disabilities, so physical activities are automatically consuming a larger percentage of their maximal capacity (first barrier to being physically active). In order to test this hypothesis, objectives were: 1) To map the autonomic physiological response to exercise in people with ID, and 2) To detect abnormalities in the autonomic physiological response to exercise causing a limited maximal cardiorespiratory capacity in people with ID, in comparison to a control group without intellectual disabilities.
The work performed since the beginning of the project consists of strengthening and finalizing the study protocol, recruiting and data collection of the first half of the control group, and recruiting and data collection of individuals with ID. Recruitment of individuals with ID was hampered by the still ongoing state budget crisis in Illinois, affecting all the ID care and service providers, since they largely rely on the state budget for their staffing and activities. A wide range of recruitment activities, with a larger time investment and over a longer period than planned, resulted in a total of 18 participants with intellectual disabilities. Since these 18 participants were included towards the end of the first year of this grant project, the data collection and analysis is currently still ongoing.
Preliminary analyses comparing the first 10 participants with ID with the control group demonstrate significant differences in maximal heart rate and maximal oxygen uptake during a maximal exercise test, as well as significant differences in the systolic blood pressure and heart rate response to the change in body position from supine baseline to standing (active orthostasis) to supine recovery. Further analyses need to support this preliminary finding.
The expected results will impact the application and interpretation of exercise testing and prescription guidelines for individuals with intellectual disabilities. By taking the expected physiological differences into account, the safety and effectiveness of physical activity and exercise intervention programs for individuals with intellectual disabilities will be improved. Keeping this population as active and fit as possible contributes to a successful long-term approach to prevent health risks and preserve daily functioning skills over the entire life span.