The participant in Case 1, a 79-year-old woman with mild symptoms of dementia (Mini-Mental State Examination [MMSE] = 22), lived with her husband in a single-story condominium. She reported that she used to walk a lot for recreation but does not as much anymore, but her husband loves to ride his bike around the neighborhood. She reported not participating in any regular exercise the month prior to the program. She was still able to care for herself and assisted her husband with shopping, cooking, and cleaning activities as his physical health was not the best. She was very social and loved to visit with family in the area. The participant depicted in Case 2, a 75-year-old male with severe symptoms of dementia (MMSE = 11), lived with his wife in a single-story home with a basement and required constant assistance for all of his basic activities of daily living (ADLs) due to his cognitive status. He enjoyed watching sports and working on puzzles with his wife. His wife reported some occasional wandering behavior and difficulties attending to tasks. She was still able to take him with her on shopping trips and out to restaurants. He attended a day program for IWDs a few times per week and participated in approximately 20 min/week of regular exercise in the month prior to the study. The participant in Case 3, a 63-year-old male with moderate symptoms of dementia (MMSE = 17), lived in the community with his wife in a single-story home. He was still very active in the community and had a newborn grandson who lived nearby. He reported working out approximately 120 min/week at the local senior center including weight training. He still golfed with his friends, tended to the garden at home, and traveled to see his family in other states.
A physical assessment was completed for each participant prior to initiation of the moderate-intensity exercise intervention including comfortable and fast gait speed via the 8-foot walk test, lower extremity via 30-s chair stand test, and balance via the modified Berg Balance Scale (m-BBS). In addition, each participant completed the Geriatric Depression Scale (Short Form) to examine depressive symptoms and the Trail Making Test:Part B (TMT-B) to assess executive function. Finally, each participant completed a 16-item self-report tool to assess their perceived difficulty with both instrumental and personal ADLs. Baseline performance is summarized in Table 1.
Overall, at baseline, these participants demonstrated minimal to no deficits in strength   and balance; however, all had comfortable and fast gait speeds that were well below published normative data for age and gender.   At baseline, none of the participants revealed depressive symptoms above the recommended cut-off of 5 points.   Two (cases 2 and 3) participants were unable to complete the TMT-B due to their cognitive limitations while case 1 completed the TMT-B in 2 min and 37 s indicating no significant deficits in her executive function at baseline. All participants had different perceptions of their overall health, ranging from 0 being "poor" to 3 being "excellent," while all perceived minimal to no difficulty with their ADLs.
The intervention was a moderate-intensity home-based functional exercise program consisting of strength and balance exercises.   The functional strength and balance program was delivered individually in the participants' home by a board-certified geriatric physical therapist twice weekly for 12 weeks. Each session was composed of 4 elements: (1) Review, which examined results from previous sessions and identified of barriers to exercise completion reported by caregiver or IWD; (2) Education, which initially outlined the purpose of the intervention and provided subsequent education to improve adherence; (3) Planning allowed the utilization of available implementation strategies, based on the Strength-Based Approach Judge et al.,   to overcome barriers reported by the IWD or caregiver; and (4) Activity, which delivered a tailored functional strength and balance program based on the participant's functional status. The development of the intervention protocol was guided by principles from exercise science and the Strength-Based Approach Judge et al.,   allowing for a structured, standardized intervention protocol that is flexible to the needs of the individual participant each session. In the larger study, the intervention was found to be highly acceptable and feasible by the participants and the exercise practitioners via adherence, tolerance, and individual session evaluations highlighting engagement, fidelity to the protocol, confidence, and enjoyment. This was consistent from the beginning of the intervention throughout the 12 weeks.
Initial starting exercises were determined by placing participants in a Physical Function Group based on initial walking performance as developed by Littbrand et al. (see Table 2). All 3 participants were placed in Physical Function Group 1 throughout the intervention, which indicated they could "walk without any physical support or supervision." The therapist and participant chose initial starting exercises based on this initial performance. Due to the high-level baseline of each participant, the exercise categories included higher level functional exercises (Categories A and B) to challenge the participant. Category A included static and dynamic balance exercises in combination with lower-limb strength exercises, such as step-ups, sit to stand, forward or side lunges. Category B included dynamic balance exercises while walking, such as stepping over obstacles, tandem walk, tossing ball in air while walking.
To account for needs of this special population, strategies from the Strength-Based Approach were included in the protocol design to enhance the implementation of the intervention (Table 3). A few examples of these strategies within these 3 cases included using an external memory aid (dots on floor) to assist with foot placement during a lunge exercise; always giving the individual a choice of 2 exercises to allow them to choose a more preferred activity (eg, "would you rather do step-ups or sit to stand this time?"); cuing using one- to two-step commands such as "Charlie, get down on the floor. Okay, get back up."; and modeling each exercise prior to completion. Many of these strategies were integrated into the protocol (eg, modeling and giving 2 choices) while others were used as needed to overcome barriers by the participants (eg, targets on ground during lunges).
Over the first 2 weeks of the program, a 15RM (repetition maximum) was targeted to allow acclimation to exercises and act as a build-up process. This intensity is representative of 50% of an individual's 1RM. Target intensity of strength exercises following this initial phase ranged from 8RM to 12RM, representing 60% to 80% of a 1RM; therefore, as more repetitions were completed, the exercise intensity was increased appropriately. Once the participant was able to complete more than 12 repetitions of a particular strengthening exercise, the intensity was increased either by addition of a weighted vest, weighted belt, or medicine ball, or increased by progression of activity (eg, progress to floor to stand tasks). For example, in Case 1, she began at the initial session with a body-weight forward lunge completing 15RM then, over time, was able to complete at 20RM in subsequent sessions; therefore, she held a medicine ball for completion of 15RM, which required continued progression to 10-pound weight vest. Once she was able to complete the appropriate repetitions, this was progressed to a body-weight walking lunge in the hallway. She eventually increased to completing the walking lunge with a 20-pound weight vest. Intensity of balance exercises was altered by variation of base of support or increased compliance of surface to continue to challenge the participant's postural stability. For example, lateral hopping was initiated on a firm surface, then progressed to a compliant surface once the participant did not report a challenge.
A representation of the exercise sessions for the 3 case studies is outlined in Table 4. All 3 cases demonstrated a progression of strength and balance activities throughout the sessions as indicated by either completing more challenging exercises (eg, lunge to walking lunge; progression to floor to stand exercises; addition of dual-task component) or increased difficulty of same exercise (eg, addition of medicine ball or weighted vest; progression from firm to compliant surface). All of these progressions were completed without significant concern of injury due to the systematic progression using the multiple RM method of measuring intensity in the strength exercises. It is noteworthy that cognitive status did not hinder participation in the moderate-intensity program since the program was developed with the needs of IWDs in mind. For example, Case 2 who had severe cognitive impairment (MMSE = 11) was able to successfully complete moderate-intensity strengthening and balance activities including weighted floor to stand exercises (with 15-pound weight vest), weighted sit to stand exercises (up to a 25-pound weight vest), plyometric jumping (with 14-pound weight belt), hopping, and tandem walking. This success was likely due to conceptual frameworks that guided the development and implementation of the exercise program. Specifically, the principles of exercise science that guided the incremental increases in dosage ensuring that participants met the minimum requirements to promote beneficial adaptations. In addition, the use of functional exercises was critical in the success of the program, which allowed participants to challenge the entire neuromuscular system relying on procedural memory, which aligns with tenets from the Strength-Based Approach.