HIIT – the missing evolutionary link?


…in your training?

These days, you can’t swing a cat now without someone asking if you do ‘HIIT’ – High Intensity Interval Training, that is. Michael Mosely was commissioned to produce a whole documentary about it for Horizon and the BBC recently. Every fitness website’s got it own idea of what it means and twists it to suit their purpose. It’s everywhere, like a rash. If you didn’t know better you’d have thought it had just been discovered.

In case you don’t know, HIIT is nothing fancier than the idea of working out very hard for very short periods of time, with even shorter recoveries in between each burst of exertion. Usually the exercise to rest ratio is 2:1. Therefore in a typical session a trainee might sprint for 20 seconds, then rest for 10 seconds – and repeat 8 times. Thus the whole session last 4 minutes.

In fact this was the original formula developed by a Japanese researcher called Tabata (nobody seems to remember the rest of his name) as early as 1996. If you’re interested, you find his research papers here: http://www.ncbi.nlm.nih.gov/pubmed/8897392 In this study he showed how he could get participants fitter using the above four-minute formula in six weeks than another control group who ran at a steady, moderate state for an hour a day, five times a week over the same six week period.

In fact, surprisingly, Tabata-style training was not only more effective at improving anaerobic endurance, it was also more effective at improving aerobic or cardio-vascular endurance. Since then there have been a plethora of studies piggy-backing on this initial finding, all confirming the HIIT protocol’s effectiveness: Here’s a few of them:

So, as Michael Mosely knows, HIIT’s not exactly breaking news. What he might not know, or at least I don’t think has publically acknowledged, is that this way of training has a fine evolutionary pedigree and in fact dates back to the dawn of humanity. Exercising like this has a basis in the lives we once had no choice but to lead, back when every living person was a hunter-gatherer and depended on their body, wits and energy resources to catch their prey and survive.

They certainly didn’t call it HIIT – I’m sure they didn’t call it anything – but it certainly happened on a regular basis, spurred on by life and death situations that ignite one of the most basic of human reactions. It’s one we’ve all actually heard about: fight or flight. I first became aware of its capacity for improving physical capacity when I was faced with my own life-or-death, fight-or-flight moment in the African bush when training to be a game ranger.

In my 20s I spent time in the Sabi Sands nature reserve of South Africa with PretoriaUniversity’s Botany department learning the requisite skills to guide, enlighten, protect and entertain seekers of the Big Five as they ventured into the bush on foot or Landrover. I don’t think I would have ever made the connection between so-called ‘primitive’ peoples and the key to great health and fitness had it not been for this period of my life.

By sheer good fortune I was exposed to an effortless, natural formula for fitness and health.  I learnt what natural fitness is – and what it isn’t. I learn how it’s a natural part of our evolutionary inheritance and that we ignore its potential role in our lives to our detriment. It seems like an age ago now and yet strangely my memories remain vivid and sharp.

I can still hear the relentless, step-after-step crunch of our boots on the dusty shale-strewn trails. We would walk the tough, rugged terrain and I can still taste the arid dryness and recall the glorious relief offered by the merest swig of lukewarm water from a canteen. Those long, relaxed expeditions through the bush were like no walk I have experienced before or since. Every step presented a new challenge as we were forced to rebalance on uneven ground, scale steep embankments, leap small ravines, scramble up banks, duck under vines and thread our way through rocky, dried up river beds.

It was the sheer variety of movement that made a day of walking a challenge; yet it was never boring, repetitive, grueling nor exhausting. It was fully engaging and completely natural. It felt as if I was leading the life I was born to lead.

For our ancestors, every day was one long camping and hiking trip

Within a few weeks of this, my pasty English legs had turned bronze and I had become conditioned to the myriad of new challenges that had initially so shocked my system. Only a week or two into the course, unless I was required to carry extra weight that day, my legs seemed to move under me as if on autopilot, gracefully finding the perfect foot position and weight distribution for each step. My legs just seemed to flow underneath me without any undue effort or conscious thought.

My days spent in the African bush showed me how fitness could come without fuss and that health runs far deeper than simply not being too fat or too thin.

Slow and steady: More than 90% of our movement was low pace, at a speed at which breathing was unaffected and conversation was easy. No, it was nothing like Tabata recommended. It was all very slow and ponderous – relaxing even. Conventional training programmes will tell you this sort of effortless movement is no use to us. “You can’t get fit walking,” we’re all told. “Unless you’re pushing hard, breathing hard and ‘feeling the burn’ you’ll never get the results you want” is the oft-repeated myth.

On the back of this theory, punishing workouts of 30 minutes and over become the norm. However, from my experience, this is utterly unnecessary and probably results in nothing more than short-term gains, quickly lost. Certainly my days in Africa very rarely contained anything that remotely resembled the sort of punishing session your average club runners puts themselves through or somebody following the newest P90x DVD or Insanity workout.

According to conventional theory, what I was doing shouldn’t be nearly enough to have made a difference – and yet I felt fitter and healthier than I had ever done in my whole life. Even after a 10-hour day on the trail, I rose the next morning raring to go without aches or pain. Through all the apparent hardship, my body felt lighter. Life was lighter. There were a handful of days however that fell outside this leisurely easy pace

On a handful of occasions the ‘no-hurry’ walking and carrying very much took a back seat. In particular, the one event that broke the day’s gentle pattern was our brush with buffalo – one of the most dangerous animals in Africa. This was an event which will remain etched in my mind forever. Rito, our indomitable guide and protector, was scouting ahead as usual, seemingly gliding over the ground in his usual way through the dense bush. Our quiet march was brought to an abrupt halt when his slim, muscled torso instantly froze on the path ahead. His arm slowly rose and hand made a fist to signal the need for absolute stillness.

Buffalo – Run like hell!

To find out why we ended up running full pelt from these angry buffs, you’ll have to read the book – but this fight or flight response was the missing piece of the puzzle for me. It was certainly what my medium pace, medium intensity, medium interest, plodding workouts I had been following at home had been sorely lacking.

Nowadays I rarely get an opportunity to get the same sort of high-adrenaline buzz that running smack into the middle of a hide of buffalo provides. However I still aim for that level of intensity in my training once or twice a week. Unlike others who relentlessly pound the treadmill, going redder in the face by the minute, four minutes is quite enough effort for me.

If it’s not then I know I’ve simply held back and not honored a simple formula for performance discovered developed over hundreds of millennia (now trotted out as HIIT, a super-dooper new discovery) . A few minutes later I’ll be back at a gentle trot, walking or lying down under a tree. Deep down, I’m a lazy guy – and I don’t want to over do anything after all…