High-intensity interval training in cardiac rehabilitation: a multi-centre randomized controlled trial

Area of Science:

• Cardiology
• Exercise Physiology
• Rehabilitation Medicine

Background:

• Lack of international consensus on high-intensity interval training (HIIT) for coronary artery disease (CAD) patients in cardiac rehabilitation (CR).
• Need to assess the effectiveness and safety of low-volume HIIT versus moderate-intensity steady-state (MISS) exercise in CAD patients.

Purpose of the Study:

• To compare the clinical effectiveness and safety of low-volume HIIT against MISS exercise in patients with CAD.
• To evaluate the impact of HIIT on cardiorespiratory fitness and cardiovascular disease risk markers.

Main Methods:

• Multi-centre randomized controlled trial (RCT) involving 382 patients with stable CAD.
• Participants were randomized to 8 weeks of twice-weekly HIIT (10x1 min vigorous intervals) or MISS (20-40 min moderate continuous exercise).
• Primary outcome was change in peak oxygen uptake (VO2 peak) at 8 weeks; secondary outcomes included risk markers and adverse events.

Main Results:

• HIIT resulted in a significantly greater improvement in VO2 peak compared to MISS (1.04 mL.kg-1.min-1 difference, P=0.002).
• Low-volume HIIT was safe and well-tolerated, with only one serious adverse event possibly related to the intervention.
• Improvements in cardiorespiratory fitness with HIIT were clinically meaningful.

Conclusions:

• Low-volume HIIT is a safe, effective, and clinically meaningful intervention for improving cardiorespiratory fitness in stable CAD patients.
• HIIT offers a superior alternative or adjunct to MISS exercise in cardiac rehabilitation programs.
• Consideration of HIIT in CR programs can enhance patient outcomes and exercise capacity.