February 23, 2015In TrainingBy Sean Lerwill8 Minutes

Last week I put out my “dirty-dozen” HIIT training session. In response people have asked me if I prefer HIIT to LISS. Considering I was a county 400metre runner and county cross-country runner as a school boy, I’ve grown up enjoying both. In my twenties, while working as a Marine I definitely favoured the LISS (although it didn’t feel very “Low Intensity”) as I would train 5km, 10km and hour-long runs (trying to cover as much distance as possible in the hour) weekly. Nowadays, I do far less LISS, maybe once every few weeks – more in the summer when the weather is nice! I prefer HIIT; it fits better with my chosen fitness gains, is quicker and more efficient and for me, like my old 400metre days, gives me one hell of a sense of accomplishment but without the need for a 36mins 10km slog!

These are the top ten benefits of HIIT as I see it:

1. Efficiency

We all have extremely busy lives. Mobile phones, tablets and PCs have meant that we are contactable 24/7 and rarely get time to eat and sleep, let alone train. I make time as my livelihood relies on it, but even I’m short on occasions. The beauty of a HIIT session is it can be as short as 6minutes (including warm-up). Ideally 15-20mins should be spared and up to 30mins if you want a good warm-up and time to stop sweating before donning the suit again. I think nearly everyone can fit that in before, during or after work at least 2 – 3 days a week.

2. Fat burning

HIIT training burns more calories per minute of exercise than LISS training, simply because it is far more intense. I appreciate training is not all about calorie burning; a simple argument could be that 10mins of HIIT may burn more calories than 10mins of LISS, but what if I continue my LISS for 60mins, then I’ll burn more calories overall. The key to HIIT however is that the very high intensity means the body is in repair for a good 24hrs after the session, which requires more calories to enable that repair and recovery. This aids fat burning far more than LISS over the day or so after a HIIT session.

3. Fitness gains

HIIT principles have been at the forefront of showing that both aerobic and anaerobic gains can be made from HIIT training, and that actually, HIIT training produces better fitness gains in both aerobic and anaerobic zones than LISS training does. If fitness rather than aesthetics is your goal, then getting out of your comfort zone and performing HIIT will certainly do it for you. Just try to progress each session: more reps, less rest, faster pace, longer intervals etc.

4. Healthy heart

In tandem with above, Tabata’s HIIT principles have shown both increases in aerobic and anaerobic fitness. Both are linked to a better functioning cardiovascular system, meaning that heart and lung health is improved. A healthy CV system should be the aim of anyone exercising for health – and perhaps a bit more of a focus for the rest of us fixated by aesthetic and fat loss goals!

5. All you need is you

Whereas for many training sessions you need a gym or at least some form of kit and equipment, for HIIT you simply need you. The simplest form being sprints, which can literally be done anywhere. Sometimes kit and equipment can be off-putting, for example if you’re not a good skipper and using skipping to perform HIIT, the intensity can be lost in favour of the technique. Simply sprint and a great session is there waiting.

6. Perform almost anywhere

Simply put, HIIT can be performed almost anywhere. The simplest form is obviously sprinting from one point to another as stated above. To do this all you need is a small area to run on: a clear road, sports pitch, dirt track, even the deck of a ship. It really is very versatile. I’ve even performed HIIT TRX jump squats in a hotel room to Tabata timings.

Sean Lerwill enjoys the benefits of HIIT

7. Pro muscle

LISS has always been associated with losing weight, but not necessarily the right weight. We want to be losing fat, yet often people are breaking down muscle tissue with excessive LISS training. Due to its high intensity and the cascade of hormones that high intensity training initiates, HIIT is actually pro-muscle building. For anyone wanting to achieve or maintain a better physique/figure, that is just another reason why HIIT is favourable.

8. Increased metabolism

Studies have shown that HIIT increases the production of human growth hormone over 24hours after a session. HGH has a host of effects, including increased metabolic rate and muscle growth. HGH declines as we all get older, yet higher levels helps us stay looking/feeling younger for longer. So basically, by performing regular HIIT sessions and in turn ramping up HGH levels you could be helping your body stay lean and stay younger looking. Hopefully…!

9. Sense of achievement

I think it’s important in life to get a sense of achievement. Not just from fitness sessions, but from everything we do. I know for me, that if I feel I’ve achieved something it spurs me on to try harder, to achieve more, to progress. But equally, it encourages me to achieve in other areas of my life. I find the sense of achievement from a really hard interval session exhilarating. It kind of makes all the little things in life go away for a while. I’m sure there’s a little part of me that’s addicted to the adrenaline and endorphins released from a hard HIIT session!

10. It’s tough

I like my training to be tough. I’m not sure if it’s from my childhood, my Marine days or just in-built, but I want to leave the gym/training area knowing I’ve worked hard and that my intensity will be sparking changes in my body. If you do HIIT right, you know you’ve worked.

So there you have it, for me the top ten reasons why HIIT should be part of everyone’s training, whether sprinting on the track, cycling on the watt bike, lengths of the pool of 500m intervals on the rower, give HIIT a go and see the changes it’ll have on your physical and mental wellbeing.