Cardiorespiratory Fitness Benefits of High-Intensity Interval Training After Stroke: A Randomized Controlled Trial

Area of Science:

• Exercise Physiology
• Neurological Rehabilitation
• Cardiovascular Health

Background:

• Limited evidence exists on the efficacy of short-interval high-intensity interval training (HIIT) for enhancing cardiorespiratory fitness (V̇O₂peak) post-stroke.
• Stroke survivors often experience reduced physical capacity, necessitating effective rehabilitation strategies.

Purpose of the Study:

• To compare the 12-week effects of short-interval HIIT versus moderate-intensity continuous training (MICT) on V̇O₂peak in individuals post-stroke.
• To assess the impact of these training modalities on cardiovascular risk factors and mobility outcomes.

Main Methods:

• A multi-site, 12-week randomized controlled trial (NCT03614585) involving 82 participants (≥6 months post-stroke).
• Participants were randomized to either 3 days/week of HIIT (10x1 min at 80%-100% heart rate reserve with 1 min recovery) or MICT (20-30 min at 40%-60% heart rate reserve).
• V̇O₂peak, carotid-femoral pulse wave velocity, blood pressure, waist-hip ratio, 6-minute walk test, and 10 m gait speed were measured. Analyses used linear mixed models.

Main Results:

• The HIIT group demonstrated significantly greater improvements in V̇O₂peak (∆3.52 mL/kg·min) compared to the MICT group (∆1.71 mL/kg·min) at 12 weeks (P=0.004).
• No significant differences were observed between groups for V̇O₂peak at the 8-week follow-up.
• No significant group-by-time interactions were found for cardiovascular risk factors or mobility outcomes.

Conclusions:

• Short-interval HIIT is a potentially effective alternative to MICT for improving cardiorespiratory fitness (V̇O₂peak) 12 weeks post-intervention in stroke survivors.
• Further research is warranted to explore long-term effects and impact on other functional outcomes.