Feasibility and safety of high-intensity interval training for the rehabilitation of geriatric inpatients (HIITERGY) a pilot randomized study

BACKGROUND: High-intensity interval training (HIIT) has been shown to be more effective than moderate-intensity continuous training (MICT) for the physical rehabilitation. However, data on its suitability for older hospitalized patients is scarce. METHODS: Randomized controlled trial in a hospital setting. Inclusion of 100 patients, ≥65 years old, hospitalized for rehabilitation after an acute medical condition, in a two-week rehabilitation program of either four HIIT or three MICT sessions per week. Completion was defined as participation in all but two planned sessions accomplishing ≥50% of each session. We assessed: upper-limb muscle strength (handgrip isometric strength test), lower-limb muscle strength (quadriceps and ankle flexion and extension tests); gait speed and spatio-temporal parameters (instrumented walkway), and exercise capacity (6-min walk test). All adverse events were recorded as safety endpoints. RESULTS: An intention-to-treat analysis showed a 44% completion rate for the HIIT group (95% CI, 30–59) and 77% for MICT (95% CI, 55–82). A modified intention-to-treat analysis restricted to patients who participated in ≥1 session showed an 88% completion rate in the HIIT group (95%CI, 69–97) and an 80% completion rate in MICT (95%CI, 65–90). The exercises most frequently undertaken were the pedal exerciser (54%) and the NuStep (32%). There were no significant differences in the various measures. No serious adverse events occurred. CONCLUSION: A HIIT rehabilitation program for this population was feasible, safe and had a high adherence rate. TRIAL REGISTRATION NUMBER: Clinicatrials.gov ID: NCT02318459. Trial registration date: November 7th, 2014. Retrospectively registered. This study adheres to the CONSORT guidelines.