Throughout the world today, an increasingly sedentary lifestyle has become a widespread problem, facilitating the development, and severity, of many serious conditions such as type II diabetes, hypertension, heart disease, peripheral arterial disease, stroke, osteoporosis, cancer, and more (4,5,7,16,22). Certainly, a remedy for this problem is to become more physically active; and, resistance training programs have been shown to be quite beneficial. In fact, multiple studies have been conducted, which elucidate the benefits of resistance training programs for adults, both with and without physical disabilities, and demonstrate improvement through increased muscular strength and endurance, aerobic and physical work capacity, body composition, and metabolic function (4,7,8,29,31,37,45,47). However, few studies have shown the benefits of physical fitness and strength training for adolescents and young adults with intellectual disabilities (IDs) (6,10,15,32,43). Furthermore, individuals with ID are at a greater risk of premature aging leading to deconditioning and morbidity (21). Indeed, poor balance and manual dexterity can lead to undesirable health issues, such as an increased risk of falling and difficulty performing vocational tasks, social tasks, and activities of daily living (ADLs). An increase in core muscle strength from a variety of exercises can improve balance levels in preparation for the aforementioned activities (33). Interestingly, Rimmer and Kelly showed that a high-intensity resistance training program can induce dramatic increases in muscular strength and endurance in this population in as little as 9 weeks (32). Lower volume and intensity training programs have not been evaluated despite their apparent logistic advantages.
Many competitions such as Lift America and Special Olympics provide opportunities for adolescents with ID to engage in physical activity and lower their risk of health problems. With the increasing number of Special Olympics athletes (SOAs) worldwide (currently 2.2 million), there is a great need for more research within this unique population regarding the benefits of strength and endurance training and physical fitness programs (35,36). Currently, there are plentiful fitness facilities for the mainstream population, but accessibility remains a concern for individuals with ID and other physical disabilities. With an accessible facility, and trained supervisors and volunteers, people with ID are able to engage in a fitness program that can improve their cardiac functional capacity, muscular endurance, flexibility, and overall level of physical fitness and social skills, and self-efficacy (12,24,26,30,41,42,46).
The purpose of this study was to examine the effects of a moderate intensity supervised resistance training program on SOAs aged 19-24 with ID in comparison to similarly aged typically developed volunteers (TDs) who also served as strength coaches. We hypothesized that (a) strength as assessed with predicted 1 repetition maximum weight would increase after training and (b) that the improvements would be similar for both the SOAs and TDs.
Experimental Approach to the Problem
The SOAs and TDs participated in the same program of resistance training consisting of 10-12 sessions over a 3-month period during the fall. A true control group was not included because the investigators did not want to deprive the SOAs of the chance to participate in a potentially beneficial training program. Thus, a comparison group was used (TDs). Special Olympics athletes participated in training sessions lasting approximately 50 minutes under the supervision of the TDs and other trainers. These sessions began with a 5-minute warm-up activity including a warm-up walk/run and brief stretching of upper and lower extremities (17,19,39). After the warm-up, SOAs spent the next 20-25 minutes engaging in resistance training exercises on the 5 assigned Med-X (Med-X, Ocala, FL, USA) machines in the UF Living Well fitness facility. These machines included the chest press (CP), seated row (SR), leg extension (LE), leg curl (LC), and abdominal crunch (AC). Major muscle groups used during ADLs and athletic events were emphasized. This type of weight training is particularly important for our SOAs who need both strength and stability in their vocational tasks (e.g., bagging and carrying groceries at supermarkets, stocking shelves, and janitorial tasks).
During each session, 8-12 reps were completed for each exercise. After the athletes were able to complete 12 reps at a specific weight, an average of 2-4 lbs was added for the next training session as long as a minimum of 8 reps was achievable. The last component of our program involved both the SOAs and all TDs in group games and sports-skill learning activities (for 15-20 minutes), a part of inclusion learning. Participation by all for this portion of the program was important because it combined socialization with physical activity. Maximal participation was achieved through modification of all activities to each participant's capability and encouragement from the TDs (15,42). After the conclusion of the training session for the SOAs, the comparative TDs engaged in the same resistance weight training exercises. They used the same 5 machines and followed the same procedures as the SOAs, completing 8-12 reps on each machine and increasing the weight when accomplishing 12 reps.
The participant pool consisted of 15 SOAs and 17 TDs; both genders were represented; ages ranged from 19 to 24 for both groups (Table 1). Each subject was informed of the experimental risks before participation. The SOAs volunteered for the study with consent from their teachers, parents/legal guardians, and physician approval, which included the completion of Special Olympics medical release forms. Further, the parents/legal guardians completed the university's Institutional Review Board (IRB) approved Informed Consent Form (ICF), and each student, under the direct supervision of parent/legal guardian, completed the ICF Assent Script approved by the IRB at the University of Florida (UF). Typically developed volunteers from UF, who completed an ICF approved by the university's IRB, made up the comparison group of the study. The SOAs were recruited from the Sidney Lanier Center (SLC) in Florida were involved in the study as part of their physical education class. These students had varying degrees of mild to moderate IDs (1) and had competitive experience in basketball, bowling, track and field, and swimming. Some of these individuals had secondary conditions such as mild cerebral palsy or autism spectrum disorder, but were able to communicate, were ambulatory, and were capable of performing all of the exercises tested with supervision. Subjects had not participated in weight training for at least 5 months before the start of the study. The Principal Investigator, SLC instructors, UF Living Well staff, College of Health and Human Performance interns, and student volunteers supervised participation.
All SOAs and TDs were evaluated during the first session to set a baseline (pretest) weight as a benchmark for comparison and again during the last session to measure a posttest weight to evaluate improvements. These weights were established as the maximum weight in which the participant was able to complete at least 8 reps. Each machine was adjusted according to the manufacturer's instructions to ensure proper mechanics during exercise for each participant. These settings were recorded and used through the study. The “predicted 1-repetition maximum” (1RM) was chosen as a dependent variable because isotonic strength values can be used to monitor the effects of training interventions, are highly correlated with actual 1RM values (r = 0.89-0.96), and are recommended for novice lifters or when the risk of injury is unacceptably high (2). The predicted 1RM was calculated by the weight lifted and the number of repetitions performed (5,18). Typically developed volunteers were taught proper techniques and training protocols for each machine during orientation sessions before the study. Special Olympic athletes were then instructed by the TDs on the proper use of equipment and technique. The combination of consistent exercise machine settings and proper training ensured the reliability of our data. Previous research indicates physical fitness test data collected from individuals with ID have a high test-retest reliability (r = 0.80) (14). The predicted 1RM scores were used for statistical purposes. In the concluding session of the study, the same procedure was used to retest fitness status (posttesting) to see how or if changes in strength occurred.
The data from each exercise were analyzed using separate 2-way (2:group × 2:time) repeated measures analysis of variance. These tests were performed to determine any differences between pretest and posttest scores, and between SOAs and TDs. The traditional level of significance (α = 0.05) was used.
As a whole, the participants improved in all of the exercises performed (Table 2 and Figures 1 and 2). Specifically, these were the SR (F(1,30) = 99.238, p < 0.001); the LC (F(1,30) = 91.578, p < 0.001); the LE (F(1,30) = 83.253, p < 0.001); the CP (F(1,30) = 53.675, p < 0.001); and the AC (F(1,30) = 57.759, p < 0.001). No differences were noted between the SOAs and their TDs on any of the exercises: SR (F(1,30) = 0.056, p = 0.815); the LC (F(1,30) = 0.006, p = 0.937); the LE (F(1,30) = 1.347, p = 0.255); the CP (F(1,30) = 0.097, p = 0.757); and the AC (F(1,30) = 0.715, p = 0.404). No group × time interactions were detected for any of the exercises: SR (F(1,30) = 0.20, p = 0.889); the LC (F(1,30) = 0.014, p = 0.908); the LE (F(1,30) = 0.672, p = 0.419); the CP (F(1,30) = 1.969, p = 0.171); and the AC (F(1,30) = 0.430, p = 0.517).
Physical activities, including resistance training, are beneficial for everyone, and considering the greater needs and concomitant health risks for individuals with ID, they are essential. Past research has indicated that these individuals have low levels of physical fitness and body mass indices (BMIs) that are not within a healthy range of 20-25 (11,44), and in fact, this was consistent with the SOAs in our study who had a BMI of 27.0. Previous researchers have shown that individuals without ID benefit from an exercise fitness program, and it is speculated that individuals with ID may experience the same positive results (6,32,40,43). Improved muscular strength and physical fitness have been found to be positively correlated to increased productivity in this population while performing vocational tasks (6,25,27,28). In addition, previous research has shown that physical activity decreases throughout the lifespan of people with and without ID (3,23). Educating people at a young age about the benefits of a regular exercise program may promote consistency of exercise, even into middle and old age. Since the implementation of this program in 1987, each year, the participants with ID have excelled in Special Olympics competitions and more importantly demonstrated increased efficiency in their vocational tasks such as stocking shelves, bagging groceries, carrying boxes, standing for long periods of time folding laundry, and various other duties in the workplace (as measured by the total absence of supervisor complaints in this regard).
Although improvements from pre to posttesting were expected for both groups, it was interesting to note that when comparing the data between these groups, the SOAs and TDs improved similarly throughout the 3-month training program (no interactions were observed). Indeed, there was no significant difference in the rate of improved performance on various weight machines between the 2 groups. In fact, for the 32 individuals tested, 1 individual did not change predicted 1RM scores after training for LP, and 1 individual had a decrease in predicted 1RM scores after training for CP. Of the 160 evaluations (32 subjects × 5 exercises) performed, 158 indicated an increase in strength after training. These data indicate that a supervised exercise training program is equally beneficial to individuals both with, and without, ID. In addition, although the program was supervised and regulated, it may not be considered rigorous: The participants averaged only between 1 and 2 strength training session per week during the study. All the participants were limited by normal scheduling conflicts (academic holidays, doctor's appointments, and other commitments), but still managed significant gains (e.g., a range of 25-51% was observed for the 5 exercises studied). The relatively minimal addition of 1 training session per week can improve physical performance. The strength gains observed most likely are the result of neural and muscular adaptations. Neural adaptations normally occur in the first 4 weeks of training, and muscular adaptations are present after 8 workout sessions (9). The subjects tested here trained over a 3-month period and attended 10-12 sessions. Similar results would be expected for more trained individuals who engage in weight training following a 1-set design (13).
Certainly, this exercise program provided significant benefits to both the SOAs and the Vs. Before interacting with the SOAs, the TDs took part in a training session, in which they became familiar with the workout machines and the way the program was conducted. Also, they were briefed on appropriate methods of social interaction and to learn innovative ways to motivate the SOAs while they were participating in the program. As the TDs encouraged the SOAs to achieve their full potential, they were themselves motivated to participate to the fullest of their ability. In fact, many of the TDs who would not have otherwise participated in physical activity took part in the program, thereby helping themselves to lead a healthier lifestyle. All of the TDs were UF students, and each took time out of busy schedules to volunteer in this study. Other researchers have shown that participation in volunteer work and in physical activity helps to reduce stress levels and promote self-esteem and socialization of all involved (21,48). Anecdotal reports from the TDs seem to support the fact that these TDs may have benefited both socially and physically, as has been suggested in other studies (21,34), as this program necessitated communication among all of the participants. Therefore, by participating in this training program, both the SOAs and the TDs gained invaluable social interaction and physical fitness skills. In particular, the TDs were exposed to a population that they would not normally encounter on a university campus. In addition, these students are part of the age of technology…an age in which many adolescents and young adults feel more comfortable working with electronic equipment than with people. For these students, “communication” means instant messaging on the computer, emails, text messaging, social networking through the internet (Facebook, MySpace, and internet dating sites) and cell phone conversations without any face-to-face interaction (20). Therefore, this training program encouraged the TDs to go outside of their comfort zone and gain communication skills with each other, and the SOAs. Such social interactions are essential to their future careers, whatever they may be…healthcare professionals, engineers, business persons, and educators, and helping them to live life to the fullest as adults who are not afraid to communicate, face-to-face, with others.
With reasonable planning, implementation of a successful sports and fitness program involving SOAs and TDs can be easily achieved. It requires approvals and clearances, and appropriate staff training and development, enthusiastic volunteers, and an accessible fitness facility (38,42), but it is certainly possible for most communities. With respect to accessibility, other research has shown that 2 of the least compliant areas are the customer service area and the area around the weight machines; methods to rectify these problems include, the lowering of service desks, widening of aisles surrounding training equipment, Velcro attachments to ensure secure grip on machines, the availability of isotonic stretch bands to help ensure that the desired muscles are able to be trained, and most importantly an open-minded staff to provide assistance when needed (17,38,42).
Unquestionably, further research is indicated; we recommend expanding to a greater variety in age groups, gender, and IDs, and other types of disabilities. There is a critical need to improve society's awareness and appreciation of such programs, community participation is valuable, and the programs must be accessible. It is essential that more people become involved in exercise programs. Even if the catalyst to start is for philanthropic reasons alone (many continue with the program), our study has shown that these participants, without disabilities, improve and benefit similarly to their counterparts with disabilities.
Similar to recent research, this study revealed that significant strength gains can be realized by adolescents and young adults with IDs by participating twice weekly in a resistance training program (6,28,32,42,43). More importantly, the present study demonstrates that this population experiences strength gains similar to their peers without disabilities when given a supervised training program. Previous studies seem to corroborate this hypothesis (10,12,28,41); yet further research is certainly needed to examine any possible interaction effects between the volunteers and the participants, even though our study showed no differences between the groups and no interaction effects.
In addition, future research is indicated to measure possible improvements in self-esteem, attendance and performance at work, and healthy lifestyle choices, on the part of both groups, after completing resistance training programs, and any fitness training programs. Indeed, people with disabilities should not be excluded from physical fitness programs; all persons, regardless of their limitations, have the right to a lifestyle of health and physical fitness. It has been said “arguably these individuals need and benefit from such programs as much as, if not more than, their peers without disabilities” (21,34,42,48). Conversely, the present study seems to suggest that the participants without disabilities benefit as much, physically, but perhaps even more, socially, than the individuals they came to help.
The authors would like to thank Anthony Todd Delisle for his thoughtful insights with this manuscript.
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