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The Simple Secret of High-Intensity Training

About The Book

From the #1 New York Times bestselling author of The 8-Week Blood Sugar Diet and The FastDiet comes a new revolution in fitness. Lose weight and dramatically improve your health with high intensity training—just ten minutes a day, three times a week.

Hailed as “a health revolution” by the New York Times, Michael Mosley’s FastDiet—also known as the 5:2 diet—gave the world a healthy new way to lose weight through intermittent fasting. Now, Dr. Mosley addresses the essential complement to the FastDietFastExercise—teaming up with leading sports scientist Professor Jamie Timmons and super-fit health journalist Peta Bee to turn conventional wisdom on its head when it comes to working out. Responding to the latest research on high-intensity training (HIT), FastExercise dispenses with the practice of boring, time-consuming regimens, demonstrating that all it takes is half an hour a week to lower blood glucose levels, reduce your risk for disease, help you lose weight, and maximize your overall health.

Throughout the book, the authors offer a range of workouts that take just ten minutes a day, three times a week, and can be done anytime, anywhere. Whether it’s pedaling at high resistance while waiting for your kettle to boil or holding a plank during commercials, research has shown the extraordinary impact that ultra-short bursts of HIT can have, whatever your age or level of fitness.

In addition, Michael Mosley and Peta Bee break down the science behind this radically different approach to exercise and give you the tools to take advantage of the most flexible and efficient method out there. It’s a practical, enjoyable way to get maximal benefits in minimal time, short and fast, something that can become a sustainable part of your routine, as instinctive as brushing your teeth.


FastExercise Introduction
AS A MEDICALLY TRAINED JOURNALIST I frequently come across claims that seem too good to be true and often are. Occasionally, after digging around, I reconsider my original position, acknowledge that what might appear at first to be outrageous could have something in it. As the economist John Maynard Keynes once said, “When the facts change, I change my mind.”

This happened to me when, in early 2012, I first heard about intermittent fasting. My initial reaction was skepticism. I assumed it would turn out to be some variation on “detoxing” or other largely discredited views of how the body works. Nonetheless I decided to find out more as I’d recently discovered that I was a borderline diabetic with too much visceral fat (the fat that lies inside your abdomen). My father had died from a diabetes-related illness and I could see myself going down the same road.

So I set out to examine the claim that you can lose weight and get health benefits, particularly improvements in your insulin, by changing your pattern of eating. I soon came across research done in the United States and the United Kingdom which pointed to rapid fat loss and other benefits that would come from cutting my calories, not every day, but just a few days a week.

As I looked deeper I discovered intermittent fasting was backed by a significant body of animal and human research. I spoke to many eminent experts, tested the claims on myself, and made a documentary for the BBC. Then, in January 2013, I wrote a book with Mimi Spencer, The FastDiet, which summarized all this research into what we called a 5:2 diet (eat normally five days a week, cut your calories for two). Using this method, I lost over 20 pounds of fat and my blood glucose returned to a normal level. Although this was just my experience (and personal anecdotes make poor science) it was in line with a number of clinical studies done on different forms of intermittent fasting.

We still don’t know the ideal pattern for intermittent fasting, the true long-term benefits or the potential pitfalls, but since the book was published many thousands of people have followed the 5:2 regime, lost weight, and contacted me to say how easy it is. And I’m pleased to say new studies are underway.

While writing The FastDiet, one of the areas I touched on—but only briefly—was exercise. Diet and exercise are complementary, they go together like Fred Astaire and Ginger Rogers, like Batman and Robin. And, as we will see, there are interesting parallels in the way science is transforming the way we think about both.

Before making the film on fasting, I had come across a rapidly developing new area of exercise research called high-intensity interval training (HIIT), also known as HIT (high-intensity training).

One of the pioneers of this radically different approach to exercise is Jamie Timmons, Professor of Systems Biology at Loughborough University. Loughborough is home to the Centre for Olympic Studies and Research and has one of the leading sports research departments in the United Kingdom.

When we met, Jamie made what I thought was an outrageous, almost unbelievable claim. He said that I could get many of the more important benefits of exercise from just three minutes of intense exercise a week. He said that if I was prepared to give it a go he was confident that in just four weeks I would see significant changes in my biochemistry. It seemed wildly unlikely but also immensely intriguing. So I got myself properly tested and then I went for it. The results, which I discuss on this page, were a revelation.

Since I had an initial conversation with Jamie back in 2011, research on HIT has exploded, with new findings coming out all the time. Even in the eighteen months that I have been working on this book there has been a wealth of new studies providing mounting evidence that you really can get many of the same benefits, from short bursts of intense effort as you can from following the more traditional approach, or perhaps even more. Benefits which include:

• Improved aerobic fitness and endurance

• Reduced body fat

• Increased upper and lower body strength

• Improved insulin sensitivity

These research findings form the basis of what I’ve called FastExercise, a practical and enjoyable way to get the maximal benefits in the minimal time.

My coauthor, leading sports journalist and coach Peta Bee, has spent her career investigating the claims of the sport and fitness industry. Unlike me she loves exercise. She’s provided invaluable experience which has helped turn theory into practice.

The Dynamo and the Slob


Peta and I approach exercise from very different perspectives. She is fantastically sporty and has been from an early age. She runs marathons for fun and adores a good, hard workout. She has spent the last twenty years thinking, writing, and training others to share her passion.

I, on the other hand, don’t like exercise. I don’t get a high from working out or pushing myself; instead I share the views of astronaut Neil Armstrong who once said, “I believe that every human has a finite amount of heartbeats. I don’t intend to waste any of mine running around doing exercises.” Or the actor Peter O’Toole who claimed, “The only exercise I take is walking behind the coffins of friends who took exercise.”

All right, that is an exaggeration. Now aged 56, I see the need and I appreciate the value of being active. I also fully embrace the idea that we are born to move. When I was at medical school I played quite a lot of sport, went for runs, and swam. Then I started working and could no longer find the time.

Don’t get me wrong; I am not a complete slob. I love skiing, enjoy walks, relish swimming in the sea, and like being active. I don’t actually think of any of these as “exercise,” something you do because you think you should.

Exercise for me means the gym. It means going for long runs even when it is wet and cold, or trudging away on the treadmill; it is hours getting sweaty on an exercise bike or lifting heavy weights, followed by those incredulous moments when you step on the weighing scales and discover that you have hardly shifted a pound. For me, exercise is there to be endured, done because you have to, not because you want to.

If I am going to exercise I want it to be short, sharp, easy to do, and soon over. This, along with the science, is what first attracted me to HIT. Peta, as you might expect, came to HIT for different reasons.


Unlike Michael, I love exercise and the way it makes me feel. I enjoy testing my own endurance and strength and relish the fatigue that comes with being absolutely physically spent.

My love affair with exercise started when I took up athletics at primary school—a start which eventually saw me run for Wales in my teens and early twenties. My passion for understanding how the body responds to intense effort, how it is repeatedly able to push itself to new limits, led me to study sports science at university. It was during that time that I gained a grounding in the basic principles of physiology and biomechanics and this cemented my view of fitness and how to attain it. Fitness eventually became the prime focus of my career as a journalist, and for the past twenty years I have written about sports science and fitness and their impact on health and longevity.

As for HIT, in all my many years of exercising and studying the practice of exercise, I have found nothing that comes close to producing the physical and mental rewards of it. I suppose in some ways I am the living embodiment of a lifelong FastExerciser—not that I realized it until recently. My induction into the concept of intense bursts of effort with short bouts of recovery occurred when I first started athletics training. Several times a week I would sprint-jog, sprint-jog my way around the track—a practice I have kept up with varying degrees of effort to this day as I race up hills, around alternate edges of a football pitch, between lampposts, and along lines of trees.

Now, at 45, a busy, working mom, I no longer have the time or, to be honest, the inclination to spend more than an hour a day working out. Yes, I want to offset middle-age weight gain, to feel good and, of course, look as good as I can. And I want a body that performs well. But I want it fast. And that, in short, is the greatest appeal of HIT for me. If you want to discover a way to get fit quickly, with minimal time commitment, read on.

The role of science is to question. It is by doing experiments that traditional thinking is challenged and sometimes overthrown. So, where does that leave widely held exercise beliefs? Claims such as:

• To get maximum benefit you should do lots of moderate-intensity exercise

• If you exercise you will lose weight

• You should always do lengthy warm-ups before exercising

• Stretching before exercise will improve your performance and reduce your risk of injury

• We all get benefit from doing exercise

In this book we take a good, hard look at these and other claims. In the first part, Michael looks at the history and science of HIT, and his own attempts to put theory into practice. In the second part, Peta has put together a range of evidence-based FastExercise workouts, along with practical advice and tips on how to integrate HIT into your life.

We want you to be as skeptical about our conclusions as we are about others. We have included numerous references to the scientific literature that we have drawn on so that you can make your own judgments. These studies can be easily accessed through an internet search; most are free in their entirety; all are available as abstracts.

We owe an enormous debt of gratitude to the numerous scientists and volunteers who have devoted their time and their bodies to uncovering the truths about exercise and who have put themselves through a range of strenuous routines in the hope of discovering the optimal ways to work out.

No one size will fit all but we hope this book will give you the information you need to create an effective and enjoyable exercise regime that works for you.

This is a book for those who, like Michael, don’t enjoy exercise but who want to keep down the fat and stay healthy in the most effective, time-efficient way. It is for those, like Peta, who love exercise and want to get the most from it. It is also for those who are simply curious about themselves and who like having their preconceptions challenged. Enjoy.

About The Author

Photograph by David Bostock

Dr Michael Mosley is the #1 New York Times bestselling author of The FastDiet, FastExercise, FastLife, The 8-Week Blood Sugar Diet, The Clever Gut Diet, The Fast800 Diet, and Covid-19. Dr. Mosley trained to be a doctor at the Royal Free Hospital in London before joining the BBC, where he spent three decades as a science journalist and executive producer. Now freelance, he is a well-known television personality and has won numerous television awards, including an RTS (Royal Television Award), and was named Medical Journalist of the Year by the British Medical Association.

Product Details

  • Publisher: Atria Books (December 23, 2014)
  • Length: 208 pages
  • ISBN13: 9781476759982

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