Effects of Guided Exercise on Functional Performance and Independence in Adults With Intellectual Disability
Condition: Intellectual Disability; Exercise; Obesity
MeSH terms: Intellectual Disability
Study type: Interventional

Summary: 
      Adults with intellectual disabilities (ID) have significantly lower levels of fitness
      compared to the general population. The health benefits of enhanced muscular strength in the
      general population are well established. In adults with ID, increased muscular strength
      levels are positively associated with improved aerobic capacity and performance of functional
      tasks. A concerted effort has been made to design and evaluate resistance training (RT)
      interventions aimed at increasing muscular strength in adults with ID. While the findings are
      encouraging, the small number of published studies, missing or poorly described theoretical
      frameworks or familiarization protocols that guided the RT interventions, and compromised
      methodological quality raise questions about the actual effects of these interventions and
      warrant further investigation. The primary purpose of this study is to design and pilot test
      the effects of an innovative community-based multi-component RT program, Resistance Training
      for Empowerment (RT-POWER). The primary aim of RT-POWER is to improve muscular strength and
      independent functional performance in adults with ID. The trial is guided by the SCT
      theoretical framework. Adults with ID will be randomly allocated to either an experimental
      group (EG) or a control group (CG). The EG will receive the RT-POWER intervention and the CG
      will receive an RT intervention traditionally used with the general population. Stage 1 will
      consist of six familiarization sessions (2 per week for 3 weeks) and Stage 2 will consist of
      20 RT sessions (2 per week for 10 weeks). Five hypotheses will be tested: (a) The EG will
      demonstrate significantly greater increases on the chest-press and leg-press one-repetition
      maximum (1-RM) tests from baseline to Week 15 compared with the CG; (b) The EG will
      demonstrate significantly greater increases on the plank test from baseline to Week 15
      compared with the CG; (c) The EG will demonstrate significantly greater increases on the
      six-minute walk test (6MWT) from baseline to Week 15 compared with the CG; (d) The EG will
      demonstrate significantly greater decreases on the stair climb functional test (SCFT) from
      baseline to Week 15 compared with the CG; and (e) The EG will demonstrate significantly
      greater increases in the percentage of steps performed correctly and independently of four RT
      exercise tasks from baseline to Week 15 compared with the CG.
    

Detailed description: 
      Participants:

      At least 24 participants will be recruited through three disability organizations (two
      suburban and one urban), all providing transition services, supported employment, and day
      activity programs for adults with ID. The disability organizations will mail a flyer
      promoting the study, a screening questionnaire, and consent forms to all parents or legal
      guardians of adults with ID who the program directors believe met the inclusion criteria.

      Exercise Setting:

      The study will take place in the fitness-center portion of a large YMCA.

      Interventions:

      Each intervention will proceed in two stages. Stage 1 - RT-POWER Intervention. The EG will
      receive six familiarization sessions that promote all four sources of SE. The coaches will
      first explain terms commonly used in RT using visuals of a model applying the terms during
      exercise, manipulatives, and live demonstrations in the gym. Two technology-enhanced
      instructional strategies, a visual activity schedule (VAS) and a video-enhanced system of
      least-to-most prompting (SLMP), will be utilized to teach participants to correctly and
      independently perform the four equipment-based RT exercise tasks (chest press, leg press,
      seated row, and military press) later included in Stage 2. In the investigators' previous
      work, each exercise task was task analyzed into the specific component steps needed for
      successful performance. The VAS will be presented to participants via the First Then Visual
      Schedule HD app (FTVS) on an iPad with a 20cm LED display and wireless headphones. In each
      familiarization session, participants will retrieve an iPad, headphones, and an exercise log
      from their coach. After a 10-min warm-up and stretching period, they will complete one set of
      10 or 12 repetitions at 50-60% of 1-RM for that exercise task estimated from the baseline
      measurements. The exercise tasks and the number of repetitions will be counterbalanced across
      sessions. Both the VAS and the video prompts were pilot tested, and content validity,
      relevance, and readability of the videos were established with the same machines and
      population in previous studies conducted by the investigators.

      Stage 1 - Control Intervention. This stage will include the same exercise setting, exercise
      tasks, orientation sessions, exercise log, natural cues, procedural script, and praise as
      described under Stage 1 - RT-POWER Intervention. The same instruction will be used to alert a
      participant to begin a task, followed by an opportunity to perform the task. If a participant
      makes a mistake that cannot be ignored (e.g., set a very heavy weight) or takes more than 15
      s to complete a step, the coach performs the step for the participant out of her/his view.
      Neither the VAS nor the SLMP will be provided to CG participants in this stage.

      Stage 2 - RT-POWER Intervention. The intervention consists of three phases, which were
      adapted from the Self-Determined Learning Model of Instruction. Participants will be taught
      by their coaches how to (a) set a goal to meet fitness needs (Phase 1), (b) make a plan to
      meet goals (Phase 2), and (c) adjust actions to complete the plan (Phase 3).

      Phase 1 involves Setting a Goal. Participants will be first interview by the coaches to
      identify their specific strengths and instructional needs and communicate preferences,
      interests, beliefs, and values pertaining to their health, employment, and home living.
      Additionally, participants will be shown graphed results of their current level of
      performance on a 20-cm LED iPad via the Goal-Setting Tracker (GST) that was developed by the
      investigators using Excel and a graphics tool. The GST converts performance data into two
      types of graphs. The bar graph is used to present continuous data that do not have a
      predefined maximum value, such as the level of muscular strength and physical function and
      the time spent in managerial and transitional tasks. The thermometer graph is used to present
      a task status toward a predefined maximum value, such as the percentage of exercise steps
      completed correctly and independently. Using the GST on a 20-cm LED iPad, the coaches teach
      participants the meaning of their levels of performance and how to set goals that are (a)
      relevant in addressing their muscular strength and functional performance, (b) specific
      (i.e., including the FITT parameters), (c) measurable, (d) realistic (i.e., difficult yet
      attainable), and (e) proximal (i.e., attainable in a short term).

      Phase 2 will involve Making a Plan. Participants will be taught to determine, implement, and
      self-monitor an exercise plan to close the gap from their current performance status to their
      goal. All exercise plans will include the four equipment-based RT exercises taught during the
      familiarization stage (i.e., chest press, leg press, seated row, and military press) and two
      floor core-strengthening exercises (i.e., crunches and prone planks). Similar to Stage 1,
      each session will start with a 10-min warm-up and stretching period. Next, for machine and
      dumbbell exercises, participants will complete 1-3 sets of 10-12 repetitions at 50-80% of 1RM
      for that exercise task. For crunches, participants will complete 1-2 sets of 10-20
      repetitions at 3 s per each repetition and with arms either by the sides, on the chest, or
      behind the head to change resistance. For planks, participants will complete 1-2 sets,
      holding the position as long as they can while trying to improve their old time. The order of
      exercise tasks and the number of repetitions will be counterbalanced across sessions.
      Following ACSM guidelines, the coaches will guide participants to focus their exercise plan
      on (a) increasing intensity (weight, speed, arm position) and/or volume (repetitions, sets,
      or time) of the RT exercises; (b) increasing or maintaining the percentage of steps of a task
      that is completed correctly and independently; and (c) decreasing time spent in managerial
      tasks (i.e., setting/cleaning up equipment) and transitional tasks (i.e., moving between
      stations). The intensity will be taught and monitored using the adult OMNI-walk/run rating of
      perceived exertion (RPE) scale, the adult OMNI-elliptical RPE scale, and the adult
      OMNI-resistance exercise RPE scale. Additionally, the performance of managerial and
      transitional tasks at each station will be monitored using a stopwatch.

      Phase 3 will involve Tracking Progress. To enhance task/goal self-efficacy, participants and
      their coaches will jointly monitor progress toward goal attainment and evaluate the success
      of the exercise plan using GST graphs and verbal instruction delivered by the coach. After
      goal attainment, following the ACSM's principles of progression, new goals will be set, and
      the whole process will be reset. If necessary, the Reinforcement Inventory for Adults will be
      used to select rewards for participation in each session or after goal attainment.

      Stage 2 - Control Intervention. The control intervention also will consist of a three-phase
      instructional process. Consistent with traditional personal training, the coaches rather than
      the participants will be the primary agents for choices, decisions, and actions. In Phase 1,
      while current levels of performance will be assessed, the results of the assessment will be
      not shown visually to the participants. The coaches will set goals that are relevant,
      specific, measurable, realistic, and proximal. Phase 2 will include the same exercise
      setting, exercises, session structure, exercise log, natural cues, procedural script, and
      praise described under the Stage 2 - RT-POWER Intervention. Coaches will design the exercise
      plan for the participants following the ACSM guidelines; however, the focus of the plan will
      be on increasing intensity (weight or speed) and/or volume (repetitions or sets) of the RT
      exercises and not on improving independent functional performance and decreasing the time in
      managerial and transitional tasks. As in the RT-POWER intervention, the three types of OMNI
      scale will be used to monitor exercise intensity at each station. Participants will be
      instructed how to perform exercise tasks with verbal and modeling prompts. Neither the VAS
      nor the SLMP will be used in this intervention. In Phase 3, the coaches rather than the
      participant will monitor progress toward goal attainment and evaluate the success of the
      exercise plan. The coach will set new goals, and the process will be reset. Other than the
      end-of-the-project reward, no additional rewards will be provided for participation in each
      session or after goal attainment.

      Procedures:

      Prior to the baseline assessments and the first intervention session, participants will
      receive one or two 70-min orientation sessions. Participants will be brought to the YMCA in
      sizes of four. The four participants will participate in the exercise program and setting
      during the same time period, but their start times will be staggered. The same coach and
      research assistant will work with the participant. The same investigators will perform the
      assessments.

      Treatment Fidelity and Social Validity:

      The study will emphasize four key areas of treatment fidelity (i.e., establishment,
      assessment, evaluation, and reporting). Procedural fidelity checks will be performed for all
      sessions using two fidelity checklists (i.e., one for each group). A trained research
      assistant who also will be in charge of video recording will note adverse events and missed
      sessions, and evaluate either in-vivo or indirectly from the recordings a coach's adherence
      to the prescribed procedures and her/his competence in delivering instruction. Two sets of
      social validity data will be collected to determine social importance, acceptability, and
      contextual relevance of the intervention and the procedures. First, the enjoyment of each
      session will be assessed with the revised Physical Activity Enjoyment Scale (PACES). Second,
      following the last training session, the coaches, the research assistants, and the
      participants' job coaches will complete an online social validity questionnaire. The
      questionnaire consists of 15 seven-point rating items adapted from a well-cited social
      validity tool measuring intervention acceptability.

      Data Analysis:

      Descriptive statistics will be computed for each dependent measure and group. The two groups
      will be examined at baseline for important demographic and clinical characteristics and to
      verify group homogeneity. Statistical significance of within-group changes between the three
      measurements will be assessed with paired-samples t-tests. The bivariate Pearson Product
      Moment correlations will be performed to explore relationships between the baseline
      performance data and the ID severity, sex, and age of the participants. An intention-to-treat
      analysis will be conducted with 24 participants to test the study's hypotheses. An analysis
      of covariance (ANCOVA) will be used to determine the significance (p < .05) of the effects
      for all outcome measures at 15 weeks between the two groups, with baseline scores used as
      covariates. Eta squared (η2) will be computed for each effect.
    

Intervention name(s): Resistance Training for Empowerment (RT-POWER); A traditional RT intervention
Intervention type(s): Behavioral; Behavioral
Intervention description(s): The EG intervention was designed using the Social Cognitive Theory and its four sources of self-efficacy to promote a participant's (a) involvement in exercise planning, (b) muscular strength, and (c) independent functional performance. It consisted of three phases, which were adapted from the Self-Determined Learning Model of Instruction (Wehmeyer et al., 2000). This model draws from theory and research on self-management and self-control (Bandura, 1986; Martin et al., 1988). Participants were taught by their coaches how to (a) set a goal to meet fitness needs (Phase 1), (b) make a plan to meet goals (Phase 2), and (c) adjust actions to complete the plan (Phase 3).; The control intervention also consisted of a three-phase instructional process. Consistent with traditional RT interventions (ACSM, 2009), the coaches rather than the participants, were the primary agents for goal-setting, exercise planning, goal attainment monitoring, and readjusting of the exercise plan. Neither the visual activity schedules nor the system of least-to-most prompts was used in this intervention.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Functional performance; Intellectual disability; Resistance training; Social cognitive theory