HIIT vs MISS Training in Cardiac Rehabilitation

A multi-centre, randomised controlled trial using Wattbike as a training tool

LACK OF CONSENSUS

Exercise is a key element of rehabilitation for people with Coronary Artery Disease (CAD). However, current guidelines for CAD vary considerably, most notably in terms of exercise intensity. Guidelines from some countries in North America and Europe recommend higher-intensity exercise, whilst others, including in the UK, do not.

Ultimately, there has been a lack of international consensus regarding the prescription of HIIT for people with coronary artery disease attending cardiac rehabilitation.

PUTTING EXERCISE INTENSITY TO THE TEST

A research project which assessed the clinical effectiveness and safety of low-volume HIIT (High-Intensity-Interval-Training) compared with MISS (moderate-intensity, steady-state) exercise training for people with CAD has published its findings (2023).

The primary objective was to evaluate changes in cardiorespiratory fitness, whilst the secondary objectives included assessment of adverse events, reliability, tolerability, cardiovascular disease risk markers, cardiac structure and function, and health-related quality of life.

WATTBIKE EXERCISE PROGRAMME

382 participants took part, aged 18-80, who had been referred for cardiac rehabilitation twice-weekly for 8-weeks. They performed either HIIT or MISS for the cardiovascular component of their exercise programme. This took place across multiple centres including Cardiff Metropolitan University, University of Hull, University Hospitals Coventry and Warwickshire NHS Trust, Atrium Health and Coventry University.

Wattbikes were installed across these centres for the low-volume HIIT element of the exercise programmes which consisted of Wattbike 1-minute intervals of vigorous exercise (>85% maximum capacity) interspersed with 1 min periods of recovery, with changes between low and high achieved by altering cadence. MISS was 20–40 min of moderate-intensity continuous exercise (60–80% maximum capacity).

DRAWING CONCLUSIONS

Conclusions of the research were that in stable CAD, low-volume HIIT improved cardiorespiratory fitness more than MISS by a clinically meaningful margin. Low-volume HIIT is a safe, well-tolerated, and clinically effective intervention that produces short-term improvement in cardiorespiratory fitness. It should be considered by all cardiac rehabilitation programmes as an addition or alternative to MISS.

This is the largest, pragmatic multicentre research project of HIIT vs MISS to date. It’s the first to adopt this approach and to report a clinically meaningful benefit of HIIT over MISS using a gold-standard, objective measure of cardiorespiratory fitness. The data from this trial is relevant to cardiac rehabilitation programmes around the world.

For the full research paperclick here

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