Optimizing Exercise Prescription in Older Adults: An Evaluation of High-intensity Strength Training

Abstract

This thesis includes five manuscripts with an overarching aim to improve exercise prescription for older adults to prevent functional decline. The first manuscript outlines the protocol for a systematic review (SR) to determine the physical and cognitive effects, and feasibility of high-intensity interval or circuit-based strength training for community-dwelling adults. The second manuscript presents the findings of the SR which support the feasibility (retention, adherence, safety) of high-intensity interval or circuit-based strengthening for older adults. Benefits in upper-extremity focused measures were found but results were mixed for lower-extremity, self-report, and cardiovascular measures. Only one trial reported any cognitive outcomes. Recommendations for future research included greater attention to cognitive outcomes, and larger, methodologically rigorous trials with equal sex representation. The third manuscript outlines the protocol for a novel pilot randomized controlled trial (RCT) and follow-up qualitative description assessing the feasibility and acceptability of home-based high-intensity functional strength training (HIFST) for older adults. Eligible participants had preclinical mobility limitations (PCML) after an injury from a slip, trip, or fall and were randomized to 12-weeks of HIFST or lower-extremity stretching, both delivered virtually. The fourth manuscript presented the findings from the pilot RCT. This is the first trial to demonstrate feasibility (based on adherence, recruitment, retention, and safety) of virtually delivered HIFST to older adults with PCML. In the HIFST group, 86.1% of sessions were completed. Exploratory analyses suggested benefits for self-reported mobility status and the Oral-Trails Making Test-B, and higher enjoyment in HIFST at several time points. The fifth manuscript presents a qualitative description based on semi-structured interviews with HIFST participants. The results suggest home-based higher strengthening exercise is acceptable to older adults with PCML. All participants reported a positive experience that met expectations. Virtual delivery and intensity were not barriers to participation. All participants described individualized plans for future physical activity.