London - So far, I have spent 43 years on this planet. But I don’t think my heart has ever beaten faster than it is now. I’m on a bike at the gym. My face is red, my body is limp, my heart feels like it is making an escape attempt.
Yet all I’ve done is cycle for 30 seconds.
What makes my cycling unusual - and garners strange glances from the woman on the treadmill behind me - is the intensity of my exercise. I’ve put every ounce of my being into going as fast as I possibly can. I am thrashing at the pedals so hard that the bike is rattling like a pneumatic drill. I’m pleased the machine is nailed to the floor.
I’m here to check out one of the most fascinating areas of health research.
Current advice from the NHS suggests that in order to stay healthy, adults should take either 150 minutes - that’s two-and-a-half hours - of “moderate” exercise a week, or 75 minutes of “vigorous” exercise.
But a growing number of studies - from proper scientists, not wacky weirdos - suggest that the benefits of exercise could be achieved in much less time if you go in for very short bursts of very high-intensity exercise.
How short? Well, just one minute, three times a week. Yes, you read that correctly. Three minutes a week. Those three minutes can be split into six bursts of 30 seconds over the week, or nine bursts of 20 seconds. But they must be totally full-on.
So-called High Intensive Training (HIT) has been bubbling around for a number of years - since at least 2005, when ground-breaking researchers at McMaster University in Canada referred to it as “sprint interval training”.
But now, argue its proponents, it’s on the verge of becoming mainstream thinking.
There have been more than a dozen published studies into HIT’s benefits; several of them, including one of 29 people in the European Journal of Applied Physiology last year, suggested that it substantially improves cardiovascular fitness and reduces the risk factors for type 2 diabetes.
British researcher Dr Jamie Timmons, professor of systems biology at Loughborough University, is at the forefront of research into HIT, leading a clinical trial of 300 overweight volunteers to help establish its benefits. His results may, in time, fundamentally change the exercise advice doled out by governments worldwide.
How does HIT work? Dr Timmons says no one knows for certain... yet. “We’ve got enough independent evidence, from different labs, to say this happens. Now we’re trying to establish why.”
One theory, says Dr Timmons, is that there may be a link “between the hormone responses we see with these short, sharp bursts of exercise, and regulation of how the liver, muscle and fat tissue talk to each other”.
Another hypothesis is that HIT protects the body’s small blood vessels from high glucose levels (which, in time, lead to diabetes) because intense muscle contractions are highly efficient at breaking down glucose stores in the muscle.
I’m here to try things out for myself. I’ve enlisted the help of Dr Tom Crisp, healthcare company Bupa’s top sports physician, who has drawn up two regimens for me. I am to try high-intensity exercise for four weeks. Then I’ll have six weeks off, doing no exercise. Finally, I will try four weeks exercising in the traditionally approved manner.
At the start and end of each exercise regimen, I will have my measurements taken in order to gauge my progress.
Among dozens of measurements, three are of particular interest: my blood pressure, my weight and my “VO2 max”.
VO2 max is a measure of aerobic fitness (it’s usually measured by getting you to breathe into an oxygen mask while on a treadmill). It tells doctors how efficiently your heart and lungs can take oxygen from the outside world and deliver it to your muscles.
A high VO2 max is an excellent predictor of future health, says Dr Timmons. Why? That, alas, remains a mystery. “We just know it is,” he says.
My starting VO2 figure is 31.7, which is rated moderate to low.
“That,” says Dr Timmons gently, “is consistent with someone who has been inactive for a long while.” (I can’t say I’m surprised: the last time I exercised seriously was more than a decade ago, when I was still in the dating market.)
Where we start on the VO2 spectrum is largely down to our genetic inheritance. But for most of us, exercise is a surefire method of improving our score.
But here’s a nasty twist: for some unknown reason, around a fifth of the population is unable to improve their VO2 score. For these poor “non-responders” - who have no idea who they are - no amount of exercise will make the all-important figure budge.
For these people, exercise will not make them any fitter at all, though it will probably still help the fight against diabetes and high blood pressure.
Am I a responder or a non-responder? A new £199 DNA test can quickly reveal the truth. Before I start exercising, I send off a sample of my saliva to XRGenomics, Dr Timmons’s company, to find out. I will receive the results at the end of my HIT regimen. (I have to say, I suspect I am a non-responder: I’ve always been useless at sport, and hated exercise.)
Anyway, it’s time to head to the gym for my first one-minute hit of HIT.
This is how it works. Though you are exercising intensely for only one minute, the session takes a little longer than that (not much, though!).
You start by cycling very slowly for three minutes; then it’s 30 seconds of madness at full pelt; three minutes very slowly again; 30 more mad seconds; then three slow minutes to finish.
So ten minutes in all. But you’re only really exercising for 10 percent of that time.
The truth is that 30 seconds feels like a very long time when you’re going crazy. The trick, I soon discover, is to keep your eyes closed. When you think 30 seconds must have elapsed, keep them closed a bit longer. Then a bit longer than that. If you’re lucky, when you look at the clock you’ll have only a few seconds left.
And how does it feel? The first time, I leave the gym feeling a little sick. This, says Dr Crisp, is down to the lactic acid that’s entered my bloodstream.
“It should wear off very quickly,” says Dr Crisp, cheerfully. It does, never to return after that initial session.
But the elation at the end of each session! The rush of endorphins - the ‘feel-good’ hormones - is very noticeable indeed. For two or three hours afterwards, I’m on a high.
In fact, I grow to enjoy my HIT time. There’s something endearingly childish about going hell for leather while others in the gym aimlessly waste their time with a bit of futile jogging.
After a few visits, I can feel the difference. One day, when I’m late to pick up my daughter from nursery, I run the half-mile from home without a second thought. Sure, I’m out of breath. But not massively so. And I feel fine.
But is this a placebo effect? After a month of HIT, what are my results?
I am flabbergasted. My VO2 max has shot up from 31.7 to 34.9, an increase of 10 percent. After a total of 12 minutes of intense exercise in a month!
Dr Crisp is amazed.
“That’s a very significant improvement. If I’m perfectly honest. I would have expected little or no change in VO2 max. If you were an elite athlete, you’d be looking for two or three percent increases.”
My DNA result arrives and confirms what I now already know: far from being a non-responder, I’m in the most responsive 40 percent of the population. This is a huge boost to my confidence. I no longer see myself as someone who’s not cut out for sport.
There’s another, rather unexpected, bonus. My blood pressure, which has been constant for ten years, has dropped noticeably, from 123/79 to 109/70. Though it was never dangerously high, this can only be good news for my future health, says Dr Crisp. “Another fantastic improvement.”
He adds that this is one of the findings of the HIT studies. “One theory is that because the high-intensity exercise sends your blood pressure quite high while you’re doing it, you get used to the adrenaline that circulates and you handle it better. So your resting blood pressure goes down. And it’s all hugely beneficial.”
The only disappointment? My weight hasn’t dropped - though oddly it does fall (by 2lb) in the four weeks when I stop exercise, even though that included the Christmas period! Dr Crisp cannot explain this - but nor can he rule out the possibility that the HIT might have raised my metabolic rate and kept it higher, even after I’d stopped exercising.
So what of my “traditional” government-approved regimen? Dr Crisp has ordered that I spend 75 minutes a week running at 70 percent of my maximum heart rate - 150 beats per minute. It’s horribly hard work. It takes for ever. It’s boring. And where’s that endorphin buzz?
And the results? My blood pressure does not go down any further. Yes, my VO2 improves - a noticeably bigger jump, in fact, from 31.5 to 40.4 - and I lose an extra 2lb of weight. But, frankly, this is all academic.
I know myself. I won’t keep it up. It’s too much like hard work. The difference with HIT is that I learned to love it - I want to make it part of my weekly routine.
But is it for everyone? Is it safe for someone in, say, their 60s or 70s? And would it work for them? Dr Timmins says it is as safe as any exercise, for anyone at any age, so long as one does not have evidence of heart disease.
All in all, I’m sold on the HIT idea. And so, possibly, is the Department of Health, which is rumoured to have asked the chief medical officer to look into HIT (the Department told the Mail there has been no “official” approach).
‘The truth about exercise is shocking and intriguing,’ says Dr Timmons. ‘It’s shocking that we’ve been given such prescriptive guidelines by government, yet have known so little. HIT has blown apart the scientific theories.’
He adds: “The work that I and others have done so far suggests that, on average, HIT leads to the same end point as the high-volume training. But the key point is this: HIT is much easier to do.
“There have been studies in America looking at how well people keep up their exercise regimes and whether they enjoy them. And the results suggest firmly that people prefer a quick dose of high intensity exercise than slogging away for hours.”
He’s right. Since the experiment stopped, I’ve stayed at the gym, but I’m back to HIT. And I’m still loving it - and feeling great. -
THE ULTIMATE QUICK-FIX PLAN
Professor Jamie Timmons explains how you, too, can do HIT...
You need to use either a cross-trainer or a static bicycle, and it needs to be heavy (ideally bolted to the floor). A treadmill won’t work because it doesn’t work all the muscles. You could do it on an outdoor bike - but for the fast bits you’d have to ride up a steep hill. Swimming won’t help either, as it doesn’t build up enough resistance in the muscles.
Go as fast as you can, as hard as you can. You need to give it 100 percent effort. Of course, as you get fitter, your 100 percent effort will get more and more powerful.
In order to get used to HIT, it’s good to start off gradually (but not slowly), so in your first session, just do one 20-second burst. In your second session, do two 20-second bursts.
Here’s how a typical session works. Go very gently (around 50W, if your bike has a digital readout for power) for two minutes. Then set the bike to high power and do a full-on burst of 20 seconds. Then gently for two minutes. Then another full-on burst of 20 seconds. Then gently for another two minutes. Then another full-on burst of 20 seconds. Finally, a gentle two minutes to cool down.
That’s nine minutes in total, of which one minute is intensive exercise. - Daily Mail