Effects of moderate- and high-intensity aerobic training program in ambulatory subjects with incomplete spinal cord injury-a randomized controlled trial.

Study Design: Randomized controlled trial.

Objectives: To investigate if high-intensity interval training (HIIT) exhibits a higher increase in physical capacity and activity levels compared to moderate-intensity training (MIT) and treatment as usual.

Setting: Sunnaas Rehabilitation Hospital.

Methods: Thirty ambulatory participants with incomplete spinal cord injury (SCI) were recruited at discharge from inpatient rehabilitation. Two intervention groups performed a 12-week individual training program at home by walking or running, depending on their physical ability. The MIT group was instructed to exercise three times a week at 70% of maximal heart rate (HRmax), while the HIIT group was instructed to exercise twice a week at 85-95% of HRmax. The control group received treatment as usual. Pre- and post-tests consisted of maximal exercise testing on a treadmill (peak oxygen uptake (peak VO)), a 6-min walking test (6MWT), and 7 days of continuously activity monitoring (total daily energy expenditure (TDEE) and daily number of steps).

Results: The HIIT, MIT, and control groups showed an increase in peak VO from pre- to post-test. However, no between-group difference in physical capacity (peak VO and 6MWT) and physical activity levels (TDEE and daily number of steps) were found between these groups.

Conclusions: Performing HIIT did not exhibit a greater increase in physical capacity and activity levels than performing MIT or "treatment as usual" in ambulatory participants with SCI. Further studies are needed to elucidate both short- and long-term effects of HIIT and MIT in this SCI subpopulation.