Exercise Adherence among Adults with Mental Retardation R1.1

(Tamar Heller, Ph. D.; James Rimmer, Ph. D; Beth Marks, RN, PhD; Jasmina Sisirak, MPH)

Statement of Problem and Background

The most chronic health problems of older adults with mental retardation (MR) noted from the National Medical Expenditure Survey are high blood pressure, osteoarthritis, and heart disease (Anderson, 1997). For all these conditions physical exercise can increase health. Several studies have indicated that persons with MR have activity and VO2 levels significantly below the general population (Fernhall et al., 1995; Fujiura et al. 1997; Rimmer et al., 1995), high obesity rates, and high cholesterol levels (Rimmer et al., 1993; Rimmer et al., 1992, 1994; Rubin, et al., 1998). Rimmer et al. (1993) noted that over 75% of female adults with MR were obese.

Little investigation has been done on the effects of an exercise health promotion program on the physiological, metabolic and psychosocial outcomes of persons with MR. Nor has there been much research on ways to encourage exercise adherence in this population. The proposed research will attempt to answer many of the questions needed to enable these individuals to achieve healthier lifestyles.

Efficacy of exercise training

Only a few studies with very small samples (3-12 subjects) or no control groups examined the efficacy of physical fitness programs for adults with MR. For example, Croce (1990) found that a cardiovascular training program combined with diet and behavioral therapy techniques resulted in significant body fat reduction for 3 obese adult men with severe MR. Pitetti and Tan (1991) found that an exercise program resulted in significant fat reduction for women but not for men with MR. In a study by Rimmer and Kelly (1991), adults with MR showed dramatic improvements in strength after a 9 week strength training program in comparison with a control group. Given the methodological limitations of most of these studies, a need exists to identify training programs that will result in increased cardiovascular fitness, lower BMI, and increased strength for adults with MR.

Conceptual/Theoretical Model

Two major perspectives concerning how persons change health practices guide the present study: 1) the transtheoretical model of behavior change (Prochaska & DiClemente, 1983) and Bandura's social cognitive theory of social learning theory (Bandura, 1977; 1989). The transtheoretical model states that persons change their health behaviors by proceeding through a process of stages: precontemplation (no thought of changing), contemplation (aware of need to change), preparation (takes small steps), action (modifies behavior), and behavior maintenance (incorporates change into routine). The model allows us to understand when particular shifts in attitudes, intentions, and behaviors occur. Two studies have reported that pre-treatment stages of change according to this model are associated with movement to active participation in exercise activities (Barke & Nicholas, 1990; Marcus, Rakowski, & Rossi, 1992). This model includes the concept of decisional balance, which refers to one's evaluation of the personal gains and losses with changing behavior. Marcus and colleagues found that individuals are more likely to exercise if the perceived gains outweighed the perceived losses. However, no study has examined the applicability of this model to persons with MR.

Bandura's social cognitive theory posits that behavior change is a function of setting goals based on outcome expectations associated with the behavior change, the tasks required to achieve those goals, and self-efficacy expectations for achieving the goals (Bandura, 1977; 1989). Thus, individuals are more likely to change their exercise behaviors if they believe that: a) their current lifestyles pose threats to personally valued goals; b) exercise behaviors will help reduce the threat (outcome expectations); and c) they are personally capable of adopting the new behaviors (self-efficacy expectations). This theory has been applied widely to the study of health behaviors. Self-efficacy has been shown to be a major predictor of adherence to preventive health programs (O=Leary, 1985), and to exercise involvement (McAuley, Lox, & Duncan, 1993). Bandura also emphasizes the informative and motivational role of reinforcement and observational learning through modeling the behavior of others. Hence, environmental cues, including support from others, play an important role. Berkman (1995) notes that interventions aimed at restructuring naturally occurring networks will be more effective than those that rely on short-term constructed support groups. A few exploratory studies suggest that social support is essential in promoting positive health behaviors for adults with MR (Fox, et al., 1985; Fujiura et al., 1997). The present study is designed to investigate the applicability of both the transtheoretical model in delineating stages of behavioral change and the social cognitive model in explaining the factors predicting long-term adherence to an exercise program among adults with a life-long cognitive disability, such as adults with MR.

Research Questions or Hypotheses

The overall aims of the project were to:
1. Test the efficacy of a physical exercise program for adults with MR.
2. Test the applicability of the transtheoretical model and social cognitive theory for predicting long-term adherence to enhanced levels of physical activity in this population.

The project hadß the following hypotheses:
1. Participants in both treatment groups will exhibit enhanced physical activity and improved physiological, adaptive functioning, and psycho-social functioning compared to controls immediately after the training.
2. Participants in the group that also receives a caregiver education program will exhibit significantly greater levels of physical activity adherence over time in comparison with the other treatment group and with the controls.
3. Persons in the caregiver education group will have significantly enhanced physiological, adaptive functioning, and psychosocial outcomes in comparison with the other treatment group and with the controls.
4. Decisional balance (of pros versus cons of exercising) and perceived exercise self-efficacy will predict long-term exercise adherence.


The study is recruiting 108 adults aged 30 years and older with moderate to mild levels of MR. The criterion of age 30 years and above was chosen because many adults with MR (e.g., those with DS) experience age-related declines earlier than the general population (Heller, 1997). Individuals with more severe MR are excluded since they are not likely to develop an adequate understanding of the importance of exercise and because reliability of measures would not be adequate. A minimum of 50% of the sample are drawn from women and a minimum of 30% from minorities. The sample includes adults living in and out of the family home. They are being recruited primarily from the Chicago Association for Retarded Citizens (CARC) which serves 1190 adults with MR a year. Nearly 75% of the adults CARC serves are minorities. Another key site is the Lutheran Hospital Adult Down Syndrome Center which serves 400 adults with DS annually. Participants are also be recruited through other sites in the Chicago area that serve adults with MR.

Pre-screening evaluation protocol

Before any participant begins the exercise training, they complete a medical history questionnaire and a Clearance Form, developed by the American College of Sports Medicine. Participants undergo a graded exercise test if approved by the project's medical director. Participants who are at risk for performing a graded exercise test are ineligible for the study. The evaluation includes baseline measurements of cardiopulmonary fitness, muscular strength and endurance, flexibility, body composition, blood pressure, blood lipids, and blood glucose.

Center-based fitness intervention

The center based fitness intervention program is conducted at the DHD Center on Health Promotion for Persons with Disabilities. The program's goal is for each intervention group participant to participate in an hour a day of physical activity, three days a week. For the first two weeks of the program, participants start out at 30 to 40 minutes per session and begin the one-hour sessions at the beginning of the third week. During the first two weeks of the exercise program, participants are familiarized with the equipment and determine what exercises they want to perform. The exercise intervention consists of aerobic activity, muscle strength and endurance, and flexibility.

Intensity level of exercise program

The exercise intensity level is geared to the participant's initial fitness level. Every attempt is made to adhere to the guidelines established by the American College of Sports Medicine and the Surgeon General's Report on Physical Activity and Health, which states that a moderate level of activity is needed to achieve health benefits. The goal is to expend a minimum of 150 kilocalories per exercise session. Muscular strength and endurance activities are performed at 60 to 75% of 1-RM.

Exercise modality

The exercise modalities vary according to the preferences of the participant. Cardiorespiratory fitness activities include walking, stationary cycling, Nu-step recumbent stepping, arm ergometry, and low impact aerobics. For muscle strength and endurance, subjects perform calisthenics and use small equipment such as hand weights and elastic tubing.

Strategies to improve participation

Free transportation to the center is provided to participants. Encouraging phone calls will be used to keep the participants interested in the program. Finally, certificates and awards are presented to participants once they complete the program.

Education component for adult with MR

The RRTC's later life planning peer training program for older adults with MR (Heller et al., 1996), which includes 4 two-hour sessions on developing personal goals in the areas of health and wellness and leisure and recreation, was used to develop the Exercise and Nutrition Health Education Curriculum for Adults with Developmental Disabilities (Heller, Marks, & Ailey, 2001). The curriculum is a 12-week interactive program includes groups of 9 participants at a time. Each week, participants enjoy three 1-hour sessions, where they are encouraged to understand their attitudes toward health, food and exercise; to gain skills and knowledge about healthy eating and exercising; to identify food and exercise preferences; to participate in food preparation and exercise activities; and, to locate places in their community where they can exercise regularly. Strategies woven throughout this curriculum include making choices, self-determination, self-efficacy, self-advocacy, and rights and responsibility, along with problem-solving techniques and conflict resolution.

Education component for caregivers

The caregiver education program is provided to the primary support person of the adult with MR (family member or residential provider). It is modeled after the training we developed for support persons as part of the Making Choices as We Age: A Peer Training Manual Curriculum. Its aim is to motivate support persons to help and support the adult with MR to set health promotion goals, develop action plans, and to attain these goals. The education program is held for two hours every other week (6 sessions) during the same time that the individuals with MR are receiving their education and exercise intervention. Three of the education sessions are held jointly with the individual with MR.

Progress to Date


This project has recruited 106 subjects. There are 8 parents/ legal guardians who refused to have the participants enroll in the program after being approached. One family member and 14 subjects withdrew from the program due to medical problems, employment issues, or behavioral problems. Two guardians did not resign consents after earlier consents expired and were updated. One participant withdrew from the research during follow-up, and no reason was given. One control participant expired from alcohol poisoning 2 months after the pre-testings. To date, 49 have completed the 12-week exercise program. Fourteen participants have finished 2-year follow up assessments. Eight participants have completed 18-month follow-up and another 8 participants have finished 1-year follow-up. Twenty-three control participants have completed pre-tests and post-tests. Eight control participants are in the process of 1-year follow up assessments. A potential of 10 participants for the intervention group will be brought in for screening tests in two weeks and are expected to start the exercise program in the next few weeks. A potential of 8 participants for the intervention group are in the process to finish up baseline assessments and will start the program at the second week of August in a community-based site.


We developed, pilot tested, and conducted reliability assessments on all the new instruments. Alpha reliabilities ranged from .66 to .91 and test-retest reliabilities ranged from .48 to .72. Also, the initial pre-post test analyses of theses measures indicated that these measures were valid and sensitive to changes in treatments.

Curriculum development

We developed and pilot-tested a health behavior education curriculum, Exercise and Nutrition Health Education Curriculum for Adults with Developmental Disabilities (Heller, Marks, & Ailey, 2001) that is based on our social-cognitive model of health behavior change. The Exercise and Nutrition Health Education Curriculum is being used by Special Olympics to develop their health education program.

Key Findings and Potential Implications

The project has developed new instruments to assess social-cognitive aspects of exercise adherence for adults with cognitive impairments. These instruments have been found to be reliable and should be useful to others interested in studying exercise adherence in this population. There are no other instruments available to assess these constructs.

In pre-post-test analyses of the 34 with Down syndrome in the intervention and 18 with Down syndrome in the control group, we found participants in the intervention had significantly improved cardiovascular function, strength, and endurance as compared to participants in the control group. Participants in the intervention groups also lost more weight and were more likely to decrease their level of triglycerides and reported less pain in daily activities. In regard to psychosocial measure the participants in the intervention groups reported increases in confidence to perform exercise, positive attitude to exercise, and life satisfaction, and less barriers to exercise. These data suggest that adults with Down syndrome can understand health behavior education and benefit from an exercise and health education program.

Presentations and Publications

Heller, T., Ying, H. S., Rimmer, J.H., & Marks, B. A. (2002). Determinants of exercise in adults with cerebral palsy. Public Health Nursing.

Heller, T., Marks, B.A., & Ailey, S.H. (2001). Exercise and Nutrition Health Education Curriculum for Adults with Developmental Disabilities. RRTCADD

We presented papers at several conferences including the American Society on Aging, the American Association on Mental Retardation, the International Association for the Scientific Study of Intellectual Disabilities, the American Public Health Association, and the Gerontological Society of America. We participated in the Surgeon General Meeting on Health Disparities among Persons with MR. In addition, we have shared our assessment tools nationally and internationally. We also co-chaired a World Health Organization Task Force and Health Aging for Adults with Intellectual Disabilities that resulted in a series of white papers which were disseminated worldwide. Last November, we initiated a pre-conference invitational research symposium at the Gerontological Society of America. One of the main themes was Promoting Healthy Aging which advances the recommendations of the World Health Organization (WHO) main report on Ageing and Intellectual Disabilities: Improving Longevity and Promoting Health Aging. Our presentations at conferences and seminars are spreading the word that exercise promotion is very important for people with MR and that it requires attention to motivators and facilitators of exercise adherence.

Tamar Heller, Ph.D., (Center Director/Research Director/Projects R1.1 and R1.2 Principal Investigator) is a Professor and Interim Head of the DHD, University of Illinois at Chicago. She also directs the Rehabilitation Research and Training Center (RRTC) on Aging with Developmental Disabilities and projects on family support and health promotion interventions for individuals with developmental disabilities and their families. Dr. Heller has written over 100 publications and presented over 150 papers at major conferences on the topics of aging and developmental disabilities. She has served on the boards of the American Association on Mental Retardation, the European Course on Mental Retardation, and the boards of several leading national and international journals on disability issues.

James H. Rimmer, Ph.D., (Project R1.1 Co-Principal Investigator) is a Professor in the DHD at the University of Illinois at Chicago. For the past 20 years, Dr. Rimmer has been developing and directing exercise programs for people with disabilities. He is the sole author of the textbook, Fitness and Rehabilitation Programs for Special Populations, and has published 60+ peer-reviewed journal articles and book chapters on various topics related to physical activity, health promotion, aging and disability. Dr. Rimmer is currently directing a federally funded Center on Health Promotion Research for Persons with Disabilities and is director of the National Center on Physical Activity and Disability.

Links to:

Back to research project list