LAUSR

OBJECTIVE To examine if eight weeks of high-intensity interval training (HIIT) in addition to standard care would increase and maintain peak oxygen uptake (VO2peak) more than standard care alone in patients with stroke. DESIGN This was a single-blind, multicenter, parallel group, randomized controlled trial. SETTING Specialized rehabilitation units at three Norwegian hospitals. PARTICIPANTS Participants, three months to five years after first-ever stroke, were randomly assigned to the intervention group (n=36) or the control group (n=34), 42% women, mean (SD) age was 57.6 (9.3) years and 26.4 (14.5) months post-stroke. INTERVENTION The intervention was eight weeks, three times a week high-intensity interval treadmill training with work periods of 4x4 minutes at 85-95% of peak heart rate (HRpeak), interspersed with 3 minutes of active recovery at 50-70% of HRpeak. The control group received standard care according to national guidelines. OUTCOMES The primary outcome, analyzed by intention-to-treat, was VO2peak measured as liters per minute (L·min-1) 12 months after inclusion. Secondary outcome measures were blood pressure and blood profile. RESULTS Mean (SD) baseline VO2peak was 2.63 (1.08) versus 2.87 (0.71) L·min-1, while at 12 months VO2peak was 2.70 (1.00) versus 2.67 (0.76) L·min-1, p=0.068, in the intervention and control groups, respectively. There was a significant and greater improvement in the intervention group compared to the control group at 12 months in three out of six secondary outcomes from the peak test, but no significant differences for the blood pressure or blood profile. CONCLUSIONS The HIIT intervention, which was well-tolerated in this sample of well-functioning stroke survivors, was not superior to standard care in improving and maintaining VO2peak at the 12-month follow-up. However, secondary results from the peak test showed a significant improvement from before to immediately after the intervention.