How To Do High Intensity Interval Training

Learn how to do high intensity interval training (HIIT), why HIIT burns more calories, and how to incorporate HIIT into your training routine.

Ben Greenfield
4-minute read
Episode #56

Imagine a workout in which you burn a lot of calories and when you’re done somehow your body keeps burning more calories for hours and hours – and maybe even continues burning into the next day! Now, what if you could achieve that bonus calorie-burning effect in less than half the time of your normal workout?

Although this promise of enhanced calorie burning may seem like something you’d see in a fancy made-for-TV exercise contraption or expensive magic pill advertisement, it is actually based on a simple and well-researched concept called High Intensity Interval Training, or HIIT.

What Is High Intensity Interval Training?

The concept of High Intensity Interval Training is fairly simple. To do HIIT, you warm-up, and then you do an intense burst of cardio, followed by a full recovery period.

For example, a HIIT workout on a bicycle might involve getting on a bicycle, warming up for 5 minutes, and then performing 6 to 8 30-second efforts as hard as you can possibly go, followed by a very easy 90 seconds of pedaling between each 30-second effort. Once you’ve completed each of the hard efforts, you’re done!

With a routine such as the one just described, you can burn just as many calories as an easy one-hour bike ride, stimulate more muscle, get fitter faster, and still have time to go shopping for new clothes to fit your shrinking waistline.

How High Intensity Interval Training Works

When you exercise, your body uses oxygen to create energy. But when you reach a high intensity during exercise, your body’s demand for oxygen exceeds your ability to breathe in that much oxygen and deliver it to the muscles. When this happens, your body goes into an “oxygen debt.” Once you go into oxygen debt, not only do your muscles begin to burn and you begin to breathe hard, but you also put your body into a state where it needs to “repay” that oxygen debt after exercise.

While repaying a debt may seem like a complex topic better addressed by the Money Girl, it is actually quite easy for your body to repay oxygen debt. You simply need to breathe more and breathe deeper. And when you breathe more and breathe deeper, your body burns more calories. Depending on how hard you’ve worked, this oxygen repaying can help you burn anywhere from a few dozen to over a hundred extra calories each hour after you exercise, for up to 24 hours after you’ve finished!

Of course, this is where high intensity interval training comes in. Besides weight training, one of the best ways to create high post-exercise oxygen consumption is via the hard cardio efforts you’ll do during a HIIT routine. While it would be virtually impossible to create that oxygen debt by riding a bicycle as hard as you can for 10 minutes, you can easily split those 10 minutes into several 30-60 second efforts followed by long recovery periods, and still achieve the same calorie burning effect!


All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Ben Greenfield

Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.