Objective: This pilot study aimed to assess the efficacy of a 16-week at-home high-intensity interval training (HIIT) program among individuals with spinal cord injury (SCI).
Methods: Eight individuals (age: 47±11 (SD) years, 3 females) with SCI below the sixth thoracic vertebrae participated in a 16-week at-home HIIT program using an arm ergometer. Participants completed baseline graded exercise tests to determine target heart rate zones. HIIT was prescribed thrice per week. Each training session consisted of six one-minute bouts with a target heart rate ~80% heart rate reserve (HRR), interspersed with two minutes of recovery at ~30% HRR. A portable heart rate monitor and phone application provided visual feedback during training and allowed for measurements of adherence and compliance. Graded exercise tests were completed after 8 and 16 weeks of HIIT. Surveys were administered to assess participation, self-efficacy, and satisfaction.
Results: Participants demonstrated a decrease in submaximal cardiac output (P=0.028) and an increase in exercise capacity (peak power output, P=0.027) following HIIT, indicative of improved exercise economy and maximal work capacity. An 87% adherence rate was achieved during the HIIT program. Participants reached a high intensity of 70% HRR or greater during ~80% of intervals. The recovery HRR target was reached during only ~35% of intervals. Self-reported metrics of satisfaction and self-efficacy with at-home HIIT scored moderate to high.
Conclusion: Participants demonstrated an improvement in exercise economy and maximal work capacity following at-home HIIT. Additionally, participant adherence, compliance, satisfaction, and self-efficacy metrics suggest that at-home HIIT was easily implemented and enjoyable.
Keywords: Aerobic training; Arm ergometry; Cardiovascular health; Rehabilitative medicine.