HIIT

Is Three Minutes of Exercise Enough?



Transcript

I know I should but I don’t particularly enjoy it. I spend the time, and I never seem to make much progress, so I wanted to find out what I should be doing, how much, and why. If, like me, you thought exercise was just about pounding the streets or hitting the gym for hours on end, then prepare to be amazed.

I’ve been meeting scientists who are changing our view of exercise. They’ve discovered that we all respond to exercise in very different ways. These guys here are super responders. I’ve looked at some extraordinary new research which suggests we can get many of the health benefits of exercise from just three minutes a week.

That’s your done! It goes against absolutely everything I was taught when I was in medical school and everything I have read since. Research is also showing us how, without breaking a sweat, we can all live healthier and longer lives.

That’s a reduction of a third. You’ve got about a third less fat going around in your bloodstream. The truth about exercise has turned out to be a whole lot stranger than I’d imagined. Research coming out of laboratories is challenging old beliefs. It has altered the way I live my life, and it may alter the way you live yours.




Listen to the episode again and write down details about the specific instructions Jamie gives Michael for the HIIT protocol. Focus on the structure of the exercise and any expected benefits discussed. Try to capture information about:

  • The number of seconds Michael is expected to exercise per burst
  • .How many bursts he must complete.
  • The weekly time commitment.
  • Jamie’s reasoning behind the exercise duration and intensity.


Transcript

Michael: So, Jamie and his colleagues have shown that it’s possible to improve health markers with a remarkably short amount of exercise. It’s a new and evolving field of study that’s gained a lot of attention in recent years. Today, we’re going to introduce the HIT protocol, or High-Intensity Interval Training protocol. Over just a few minutes per week, this method can potentially help reduce how your body responds to a glucose drink.

Michael: I find this utterly unbelievable, I have to say. I knew from your research that you would say this, but it goes against everything I learned in medical school and everything I’ve read since then. How long do I have to do it?

Jamie: Today, you’ll be cycling as hard as you can for about 20 seconds, followed by a short rest. You’ll repeat this twice, so three bursts in total.

Michael: But that doesn’t sound like exercise! Three bursts of 20 seconds? And how often?

Jamie: We’d like you to do it three times a week. That adds up to just 3 minutes of high-intensity exercise per week.

Michael: Three minutes of exercise per week? That’s absolutely nothing!

Jamie: We’re going to show you that this can actually have a big impact on your metabolism and muscles, and make a real difference.

Michael: The exercise industry always says “do more, do more, do more.” The only way to benefit, they say, is by doing a lot of painful and time-consuming workouts.

Jamie: Well, you can see why that approach is promoted. If you do a lot of exercise, you end up buying more equipment, gear, running shoes, and so on. With HIT, you could even do this in your suit if you really wanted to.

Michael: Okay, if you say so.

Jamie: All right, start pedaling in three, two, one, go! Sprint as fast as you can! That’s great, keep going! Five seconds left—3, 2, 1, and stop!

Michael: Well, that’s different!




Transcript

Michael: Eighty percent of us are just too busy or too lazy to get anything close to the recommended level of 150 minutes of exercise per week. If you can’t be bothered to do lots of moderate exercise, what about one minute a week of high-intensity training, also known as HIIT? Claims are that one minute of HIIT will give you many of the benefits of standard exercise. When I first heard this idea, I have to say I was pretty dubious. But researchers have spent years studying the benefits of HIIT in regular people, so I agreed to take part in a series of tests at Nottingham University.

The procedure for the test is similar to how I still carry out my HIIT today. First, get on an exercise bike and warm up by doing gentle cycling for a couple of minutes. Then you stop, check your pace, increase the resistance on the bike to the hardest level, and go. I do 20 seconds of full effort, building up to 140 rotations per minute. After that, I cycle gently for a couple more minutes to catch my breath, then do another 20 seconds at full power. Another couple of minutes of gentle cycling, and then, if you can manage it, a final 20-second burst of maximum effort. That’s it—more than seven minutes, and the exercise for the day is complete.

You see, with HIIT, it’s quick but intense. The key isn’t so much speed as it is resistance, and essentially, it’s the amount of effort you put in over a short period of time. Studies suggest that HIIT is excellent for improving your aerobic fitness—that is, the strength of your heart and lungs—as well as your metabolic fitness, which is your body’s ability to handle high levels of blood sugar. Both of these are strong predictors of future health.

How does it work? Well, partly by increasing the number and efficiency of your mitochondria, which are the little power plants inside each of your cells. These burn up fat and sugar, so, broadly, you want more of them. HIIT also leads to the production of adrenaline and noradrenaline, two hormones that are very good at burning fat, particularly the fat around your stomach.

I did HIIT for six weeks, and I had tests done before and after. One of the tests measured my insulin response—basically, how well my body handles blood sugar. That improved by a remarkable 24 percent. I still do HIIT because I find it improves my mood, helps me control my blood sugar levels, and seems to help me manage my appetite. This is backed up by other research, including an Australian study, which found that men consumed fewer calories after very high-intensity workouts than they did after moderate exercise. This effect could aid weight loss.

If you’re frail or unfit, I recommend seeing your doctor before starting any strenuous exercise. You can do HIIT while running—just find a steep hill—or if you work in a tall office building, you could even do it on the stairs. Just don’t try it in high heels! Now, time for one final burst.

Why not add your exercise tips to the comments section below and sign up for Brit Lab?