Can three minutes of exercise a week help make you fit?

Michael Mosley on exercise bike

A few relatively short bursts of intense exercise, amounting to only a few minutes a week, can deliver many of the health and fitness benefits of hours of conventional exercise, according to new research, says Dr Michael Mosley. But how much benefit you get from either may well depend on your genes.

When I first read studies which suggested that I could make significant and measurable changes to my fitness by doing just three minutes of exercise a week, I was incredulous.

But this apparently outrageous claim is supported by many years of research done in a number of different countries including the UK, so I decided to give it a go.

Start Quote

Aerobic fitness is a measure of how good your heart and lungs are at getting oxygen into your body and is an excellent predictor of future health”

End Quote

My guide into the world of High Intensity Training (HIT), was Jamie Timmons, professor of ageing biology at Birmingham University.

Jamie assured me that by doing just three minutes of HIT a week for four weeks, I could expect to see significant changes in a number of important health indices.

The first, and the one I was most interested in, is insulin sensitivity. Insulin removes sugar from the blood, it controls fat and when it becomes ineffective you become diabetic.

My father was a diabetic and died from complications of that disease. Jamie assured me that research from a number of centres has shown that three minutes of HIT a week improves insulin sensitivity by an average of 24%.

The second improvement I was likely to see would be in my aerobic fitness. Aerobic fitness is a measure of how good your heart and lungs are at getting oxygen into your body and is an excellent predictor of future health. I asked Jamie why.

"The simple answer is we don't know," he replied. "What we do know is that it is a very, very powerful predictor of future health."

Genetic test

So if I could improve my insulin sensitivity and my aerobic fitness then that should improve my general health. But Jamie said there was a potential sting in the tail. There was a possibility that I wouldn't improve. Not because HIT doesn't work but because I've inherited the wrong genes.


Michael Mosley
  • Michael Mosley presents Horizon: The Truth About Exercise on BBC Two at 21:00 GMT on Tuesday 28 February 2012 or watch online via iplayer (UK only) afterwards at the above link

The fact is that people respond to exercise in very different ways. In one international study 1,000 people were asked to exercise four hours a week for 20 weeks. Their aerobic fitness was measured before and after starting this regime and the results were striking.

Although 15% of people made huge strides (so-called "super-responders"), 20% showed no real improvement at all ("non-responders").

There is no suggestion that the non-responders weren't exercising properly, it was simply that the exercise they were doing was not making them any aerobically fitter.

Jamie and his collaborators investigated the reasons for these variations and discovered that much of the difference could be traced to a small number of genes.

On the basis of this finding they have developed a genetic test to predict who is likely to be a responder, and who is not. Jamie offered me that test. But I would not be told the results until I had completed my HIT regime.

I agreed, had blood taken and went through some baseline tests to assess my starting point, fitness-wise. Then I began to do HIT.

Full throttle

It's actually very simple. You get on an exercise bike, warm up by doing gentle cycling for a couple of minutes, then go flat out for 20 seconds.

A couple of minutes to catch your breath, then another 20 seconds at full throttle. Another couple of minutes gentle cycling, then a final 20 seconds going hell for leather. And that's it.

Michael Mosley tries high intensity training

So how does it work? According to Jamie, and other researchers I spoke to, part of the explanation is (probably) that HIT uses far more of our muscle tissue than classic aerobic exercise.

When you do HIT, you are using not just the leg muscles, but also the upper body including arms and shoulders, so that 80% of the body's muscle cells are activated, compared to 20-40% for walking or moderate intensity jogging or cycling.

Active exercise also seems to be needed to break down the body's stores of glucose, deposited in your muscles as a substance called glycogen. Smash up these glycogen stores and you create room for more glucose to be sucked out of the blood and stored.

Somewhat sceptical I went off and dutifully did my four weeks of HIT, making a grand total of 12 minutes of intense exercise and 36 minutes of gentle pedalling. I then went back to the lab to be retested.


The results were mixed. My insulin sensitivity had improved by a remarkable 24%, which was extremely satisfying, but my aerobic fitness had not improved at all.

I was crestfallen, but Jamie was not surprised. It turns out that the genetic test they had done on me had suggested I was a non-responder and however much exercise I had done, and of whatever form, my aerobic fitness would not have improved. My dreams of winning Olympic gold ended there and then.

I will continue doing HIT because I can see the benefits. It won't suit everyone, because although it is short, it is extremely intense. Like any new exercise regime if you have a pre-existing medical condition you should consult your doctor before trying it.

Michael Mosley presents Horizon: The Truth About Exercise is on BBC Two at 21:00 GMT on Tuesday 28 February 2012 or watch online afterwards at the above link.


More on This Story

The BBC is not responsible for the content of external Internet sites


This entry is now closed for comments

Jump to comments pagination
  • rate this

    Comment number 83.

    The article is highlighting the benefits of exercise, in particular HIT, even if only 3 bursts of 20 seconds is beneficial. Personally, having incorporated HIT in my routines, I can say that it is a very effective way of training, especially if you have limited time and want to get the most from your workout. I would encourage anyone of you reading this to give it a go, it really works. Peace

  • rate this

    Comment number 82.

    Can three minutes of exercise make you fit?
    Well yes, if you keep repeating it

  • rate this

    Comment number 81.

    What on earth has the bible got to do with Tabata?

  • rate this

    Comment number 80.

    High intensity interval training is nothing new.. I've been doing it for years. As have many others. But 3 minutes a week is nonsense. Keep to 60 minutes of interval training a day-which will probably mean 2 minutes rest period (low intensity cardio) with 30seconds of 100% effort. This totals up to 6 minutes of full intensity and 54 minutes of steady paced (recovery) cardio per hour.

  • rate this

    Comment number 79.

    What is the point in getting fit, if you can't afford to house yourself, pay your bills and eat (any sort of diet, let alone the latest fad scientists tell us is *healthy*)?

  • rate this

    Comment number 78.

    For all of you who think 3/5 minutes can't have an affect, it's the fat thats burnt after you exercis which makes the technique so good, due to the dramtic increase in the bodies metabolism, this process has been out for years, its called the "tabata protocal", just google it and it will explain everything!

  • rate this

    Comment number 77.

    I can't exercise as I'd like due to the sudden onset of a mobility problem while relatively young. I used to be a gym bunny but I've learnt to take life at a slower pace & simply enjoy doing as much as I'm able & not worry about stuff I can't. Maybe not as fit as I'd like but I keep cheerful & don't stress about much - a lot to be said for the effect of a positive outlook on health & well-being.

  • rate this

    Comment number 76.

    I gave a bible viepoint on bodily training. It was not published for viwers to see. I then gave another similer shorter bible viewpoint same subject, tyhat was again ignored for public view. Are the BBC Horizen or this subject moderators ANTI - BIBLE?

  • rate this

    Comment number 75.

    27.PatAgonia I prefer the single sentence definition I gave earlier, because it encompasses other factors as well as the heart rate you gave, and I think it fits ( heh :) ) the dictionary definition of the word a lot better.

    But yes, I agree in general it is best to be specific, the word "fit" is a bit too general, despite that we all know what it means.

  • rate this

    Comment number 74.

    My own preferred work out is 4 lengths (50M pool) very hard front crawl in a couple of minutes followed by a length of fast hard front crawl & length of very slow leisurely back crawl repeated until I'm tired or need to get out. Its not a million miles from this idea: a burst of intense exercise followed by lower intensity exercise. A year of this has seriously improved my fitness.

  • rate this

    Comment number 73.

    3 mins a week? C'maaaaarn.

    If you know about 5 veg a day, because British people can't bare to eat 8, then you must suspect the same tactics here. :-)

  • rate this

    Comment number 72.

    Nothing new, at least for body-building where Mike Mentzer and Dorian Yates claimed to use relatively high bursts of activity in smaller amounts of time per week. Makes sense due to the fact that the human body is evolved to work - also - in that mode.

    Then you have to try if it works on you or not.

    Remember any exercise even if mild and infrequent is better for you than doing nothing.

  • rate this

    Comment number 71.

    Godly training is most beneficial. The holy Bible view says bodily training is beneficial for a little but godly devotion is beneficial for all things. These experts that have studied the genes and fitness routines sugest the bible view is correct.

  • rate this

    Comment number 70.

    #57: Is it any wonder the British are so fat when they look to do the least exercise possible?

    Just for reference, I swim an average of 4km a week and go walking on the days I'm not swimming, despite one ankle being so damaged that my surgeon expected I would never be able to swim far, or walk without a limp. I also don't live on cake.

    Still morbidly obese, though.

  • rate this

    Comment number 69.

    If you can't do 3-5 minutes exercise without looking like you're going to have heartfailure then you need a healthier base level.

  • rate this

    Comment number 68.

    Some people are in their cars, sat at a desk all day every day, then drive to their gym for their obligarory half hour of manic activity a week & think that makes them fit.
    Surely it's better to walk as much as you can, as fast as you can, get out in the sunshine as much as poss & stick to the occasional bit of sprinting after buses/ kicking a football round the park with your kids?

  • rate this

    Comment number 67.

    It's possible to do far more than 3 mins/week with a little thought. How about 20-30 pressups against the kitchen counter while the kettle boils, or a few squats, a little running on the spot. But of course the suggestion is stupid because all but the bedbound and wheelchair bound surely get more than 3 mins of walking in a week. Just pace a little faster. It's all an investment for 10 years' time

  • rate this

    Comment number 66.

    Who still remembers Charles Atlas and his claim to develop strong muscles by simply doing tension exercises for a few minutes every day?
    He lived to a ripe old age and certainly had a magnificent physique well into his 70's. I believe that all exercise should be a pleasure and not a pain unless you are trying to win some laurels in sport.

  • rate this

    Comment number 65.

    This is known as Tabata and it is not new. There are myriad exercises (running, deadlift squats, cycling, burpees and loads of things with kettlebells). As a previous user rightly pointed out, one does not require equipment (except a Gymboss). Those who lack the time or motivation to undertake regular training have nothing to lose by undertaking HIIT and should be both encouraged and praised.

  • rate this

    Comment number 64.

    Do people think we humans evolved with jogging or a leisurely hour in the gym? Lift heavy weight 3 times a week and HIIT sprint once, and stroll for couple of hours, its enough. People need to read about fitness because what was thought was good 10 years is very different today. I want to stop and shake people when i see them jogging! STOP WASTING YOUR TIME!


Page 13 of 17


More Health stories



BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.