Submaximal Exercise Testing to Dose High-Intensity Interval Training After Stroke: The FAST Randomized Clinical Trial

Area of Science:

• Neurology
• Cardiology
• Exercise Physiology

Background:

• High-intensity interval training (HIIT) enhances cardiorespiratory fitness (VO2 peak) and walking ability post-stroke.
• Previous HIIT studies often used maximal testing, limiting clinical applicability.

Purpose of the Study:

• To compare the preliminary efficacy of HIIT versus moderate-intensity continuous training (MICT) using submaximal exercise testing in stroke survivors.
• To determine if HIIT yields greater improvements in VO2 peak, vascular function, and walking outcomes compared to MICT.

Main Methods:

• A randomized trial involving 49 participants with chronic stroke, assigned to either HIIT or MICT for 4 weeks.
• Exercise intensity was prescribed based on peak power output from a submaximal test.
• HIIT involved 1-minute high-intensity intervals (65-95% PPO) with 1-minute active recovery; MICT was continuous at 45-65% PPO.

Main Results:

• Both groups showed significant improvements in VO2 peak and walking endurance.
• No significant between-group differences were observed for the primary outcome (VO2 peak).
• HIIT uniquely led to significant improvements in peripheral vascular function.

Conclusions:

• HIIT is safely implementable in stroke survivors using submaximal testing.
• Both HIIT and MICT provide clinically meaningful benefits for VO2 peak and walking post-stroke.
• HIIT's specific effect on vascular function suggests intensity-dependent adaptations.