Feasibility of remotely supervised home-based high intensity interval training and effects on aerobic fitness and body composition in healthy older adults

Aging is associated with declines in aerobic fitness and increases in adiposity, both of which increase the risk of cardiovascular disease in older adults. High intensity interval training is an effective strategy for cardiovascular disease risk reduction; however, this promising exercise regimen may be inaccessible to older adults due to weight-bearing limitations or inability to travel to a fitness center. To address these barriers, we have developed a remotely supervised, home-based exercise intervention using high intensity interval training on an all-extremity non-weight-bearing ergometer (HIIT-ANE). The purpose of this study was to investigate the hypotheses that remotely supervised home-based HIIT-ANE would be feasible and lead to improvements in aerobic fitness and body composition in healthy older adults. Twenty sedentary older adults free of major clinical disease (66±1 yrs, mean ± SE) participated in this study. HIIT-ANE was remotely delivered at home under supervision via video conferencing (Zoom) and live heart rate monitoring (Zephyr OmniSense, Medtronic). HIIT-ANE consisted of a 10-min warm-up, 4 × 4-min intervals at 90% HR max interspersed by 3 × 3-min bouts of active recovery at 70% HR max , and a 5-min cool down and was performed on 4 days/week. Feasibility was assessed throughout the 8 weeks of HIIT-ANE. Aerobic fitness (maximal oxygen consumption) and body composition (dual-energy x-ray absorptiometry) were assessed at baseline and following an 8-week control period of normal lifestyle and an 8-week HIIT-ANE period. We found that exercise compliance to HIIT-ANE — the number of completed sessions relative to the number of scheduled sessions — was 96±1% and there were no adverse events related to the exercise intervention. Aerobic fitness increased in response to HIIT-ANE (baseline vs. post-HIIT-ANE: 23.7±1.2 vs. 27.0±1.1 ml/kg/min, P=0.001; pre- and post-HIIT-ANE: 22.5±1.2 vs. 27.0±1.1 ml/kg/min, P<0.001), but decreased following the control period (23.7±1.2 vs. 22.5±1.2 ml/kg/min, P=0.04). Body fat % (36±2 vs. 35±2%, P=0.001) and fat mass (28.4±2.0 vs. 27.0±2.0 kg, P=0.003) decreased following HIIT-ANE, but fat free mass did not significantly change ( P=0.05 for time effect; 48.5±1.7 vs. 49.3±1.7 kg). Body weight and body mass index did not change throughout the study duration ( P≥0.8 for time effect). In conclusion, remotely supervised home-based HIIT-ANE was feasible and safe and was associated with improved aerobic fitness and body composition in healthy older adults. This work was supported by the National Institute of Aging grant AG063143. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.