Pilot study of a high-intensity interval training program in older adults: Safety, feasibility, functional fitness and cognitive effects

Exercise can boost physical and cognitive health in older adults. However, there are a lack of accessible exercise programs that foster adherence among older adults. In this study, we aimed to establish the safety and feasibility of APEX, a new exercise program designed to optimize fitness and cognitive gains for older adults, in addition to evaluating its acute physiological effects, and assessing its possible effects on functional fitness and cognition among healthy older adults. APEX utilizes a multimodal progressive high-intensity interval training (HIIT) design, with high-intensity intervals focused on enhancing cardiovascular fitness and muscle strength, and recovery intervals that incorporate balance and mobility exercises. The APEX training was tested in healthy older adults (n=4) over the course of four weeks. Ultimately, APEX was found to be safe and feasible, with no adverse events and high adherence. Participants met heart rate targets for all of the high-intensity exercises, and all intervals had a significant difference in heart rates between high-intensity and recovery periods in linear effects models (p<0.001). Improvements in functional fitness were observed in aerobic endurance, lower body strength, and balance. The intervention was also associated with positive trends in the cognitive domains of information processing, working memory, executive control, and attention. APEX offers a promising alternative to traditional cardiovascular exercise modalities for older adults with additional benefits for functional fitness and cognition. These results encourage further testing of the APEX program in older adults and different clinical populations.