Fatloss showdown: MISST versus HIIT

Two different forms of training, each promising superior fat-burning benefits but which one is best? There’s only one way to find out!

What is Moderate Intensity Steady State Training (MISST)?

In a nutshell, steady state training is where you burn calories by exercising at continuous steady effort with no variance in energy output. Doing it at a moderate intensity means working at at 65-70% of your maximum heart rate.

The theory is that it promotes fat loss because when you work aerobically – where you rely on oxygen to meet your energy demands – you use your body’s fat to power the aerobic process, rather than the glycogen supplies stored in your muscles.

To burn significant amounts of fat, you’ll want to do quite lengthy steady state workouts – fans of this type of fat loss training, primarily bodybuilders and physique models, will do them for between 60-90 minutes each time.

And what about High Intensity Interval Training (HIIT)?

HIIT is when you alternate periods of high and low intensity exercise. So, for example, you run, cycle or lift hard for a set period of time, then walk, freewheel or rest for a set period before repeating the sequence for as long as your workout lasts – usually between four and 30 minutes.

During the high intensity periods it’s generally recommended that you work at 80-90% of your maximum heart rate – that’s the intensity at which that your body can’t transport enough oxygen to your muscles to process the lactic acid that builds up.

These high intensity periods are anaerobic – where you use glycogen supplies stored in your muscles for energy. And it’s during them that you create an oxygen debt you body has to pay back. It attempts to do this during the lower intensity periods, which are aerobic because it’s during them that your body starts to use oxygen to convert stored carbohydrate into glycogen for the next high intensity period.

Although the lower intensity sections do offer some opportunity to recover, they can’t fully repay the oxygen debt of the high intensity periods and this triggers excess post oxygen consumption (EPOC).

This is where, post-workout, your body continues to process the lactic acid you built up during training and restore your body’s glycogen supplies to normal levels. It uses oxygen to complete this process, meaning you’re burning fat the whole time it’s taking place. And, according to a highly-regarded study on EPOC training that was published in the European Journal of Applied Physiology in 2006, that process lasts a whopping 38 hours.

OK, so which burns more fat?

With the right conditions both will burn fat. Certain types of MISST (think cycling or swimming), while more repetitive, can be gentler on the body than the more explosive movements of, say, a HIIT resistance session, meaning less risk of you getting injured and faster recovery.

It’s important to remember, however, that the more intense the exercise the more calories you burn. So if you were going to do HIIT workout and a lower-intensity steady state session for the same length of time you’d burn more calories doing the HIIT workout.

But because of the more taxing, dynamic nature of HIIT, you wouldn’t, be able to perform it for as long as steady state training, which means that during a standard steady state session, say between 60-90 minutes, you’d be able to burn more calories than a shorter HIIT one. So, ultimately, if you’re trying to maximise fat loss within a session, and aren’t worried about how long it will take, moderate intensity steady state train might be your best option.

The situation changes, however, if we factor in what happens after the session and that you might have a limited window to time to train. During a 2007 study from Florida University State in which one group of people performed a HIIT session and an another a steady-state routine, with both groups burning the same number of calories, the HIIT group torched 10% more in the 24 hours that followed.

‘HIIT sessions are my weapon of choice for torching body fat,’ says leading British trainer Nick Cameron ‘Not just the intra-workout calories they burn, but also the EPOC afterburn effect. If one of my clients is short on time and wants maximum fat loss bang for their buck, HIIT is what I get them to do.’

To train with Nick Cameron, go to cameronfit.com

Advice is for information only and should not replace medical care or recommendations. Please check with your GP before embarking on exercise or nutrition regimes for the first time.