Effects of High-Intensity Interval Training after Stroke (The HIIT Stroke Study) on Physical and Cognitive Function: A Multicenter Randomized Controlled Trial: Treadmill interval training after stroke.

Abstract

OBJECTIVE\nTo assess the effects of high-intensity interval training (HIIT) on physical, mental, and cognitive functioning after stroke.\n\n\nDESIGN\nThe HIIT Stroke Study was a single-blind, multicenter, parallel-group, randomized controlled trial.\n\n\nSETTING\nSpecialized rehabilitation units at 3 Norwegian hospitals.\n\n\nPARTICIPANTS\nAdult stroke survivors (N=70) 3 months to 5 years after a first-ever stroke.\n\n\nINTERVENTION\nParticipants were randomized to standard care in combination with 4\u202f×\u202f4 minutes of treadmill HIIT at 85-95% of peak heart rate or standard care only.\n\n\nOUTCOMES\nOutcomes were measured using physical, mental, and cognitive tests and the Functional Independent Measure (FIM) and Stroke Impact Scale. Linear mixed models were used to analyze differences between groups at post-test and 12-month follow-up.\n\n\nRESULTS\nMean (SD) age was 57.6 (9.2) and 58.7 (9.2) years in the intervention and control groups, respectively. The intervention group showed a significant treatment effect (95% CI) from baseline to post-test on a six-minute walk test of 28.3 (2.80-53.77) meters, (p=0.030); Berg Balance Scale 1.27 (0.17-2.28) points (p=0.025); and Trail Making Test Part B (TMT-B) (-24.16 [-46.35 to -1.98] seconds, p=0.033). The intervention group showed significantly greater improvement on TMT-B at the 12-month follow-up (25.44 [-49.01 to -1.87] seconds, p=0.035). The control group showed significantly greater improvement in total FIM score with a treatment effect of -2.37 (-4.30 to -0.44) points (p=0.016) at the 12-month follow-up. No significant differences were identified between groups on other outcomes at any time point.\n\n\nCONCLUSIONS\nHIIT combined with standard care improved walking distance, balance, and executive function immediately after the intervention compared to standard care only. However, only TMT-B remained significant at the 12-month follow-up.