What is your fat burning zone? And how does it work?

The fat burning zone is one of the most pervasive myths in the fitness industry that just will not go away! You will probably have seen it on treadmills, cross trainers and other pieces of equipment in the gym. The press, magazines, blogs and social media constantly promote exercises that work into the fat burning zone, and we have a great deal of women who ask us about this in relation to the workouts they do with us, or workouts they do in classes, so we thought we would help clear this up for you.

The entire idea of this fat burning zone, is that you elevate your heart slightly more than you would if you were walking and you stay here for a decent period of time say 45 minutes to 60 minutes.

Sounds great, because essentially it means you don’t have to really do too much working out, just for a longer period of time. Which is why this myth tends to be so attractive; we basically don’t have to do too much strenuous work and we will burn fat. Right?

Well, there are bits missing. This myth is misleading and completely misinforming you in the way to actually get the most out of your workouts and the most fat burning.


Firstly you need to understand LISS, HIIT training and ‘fat burning’…

  • LISS is just the shorthand for ‘low intensity steady state’ and
  • HIIT just means High intensity interval training
  • ‘Fat burning’ can also be called your metabolic rate or post workout – the afterburn. This is the rate your body burns calories.

These are two types of workouts that you can do, and the ‘fat burning zone’ will usually be linked with LISS training.

(FYI for those who are new to training; LISS is where you workout at a steady low intensity pace and HIIT is where it’s quite intense; you will workout for a period of time say 30 seconds followed with a very short rest period, and you will repeat this several times)


During a long intensity steady state workout you are in fact working into a fat burning zone. So, during a LISS workout you raise your metabolic rate during the session, and for a little while after the workout.

With HIIT training, which is often an overall shorter session than a LISS session, but often more intense and feels a great deal harder, your metabolic rate (also known as after-burn) is it elevates during your session just like LISS, but the difference is that it is elevated for a lot longer post workout than it is with LISS. Meaning you burn more calories, for longer, even after you have stopped working out.


If you still don’t believe me look at this study, by Dr. Christopher Scott and the University of Southern Maine. He did a study on the total calorie burn of low intensity exercise vs. high intensity exercise.

  • Lower Intensity Group: These people cycled steadily for 3.5 mins.
  • Higher Intensity Group:  These people cycled 3 x 15 sec sprint’s as fast as possible (total exercise time 45 seconds)

The difference in calorie burn?

  • Lower Intensity Group: 29 calories (during the exercise) 39 calories (after the exercise) (total 68)
  • Higher Intensity Group: 4 calories (during the exercise) 65 calories (after the exercise) (total 69)


95% of the calories burned in the higher intensity group were burned after the exercise. Now you may be thinking, well yeah but that’s just 1 calorie different. So, just bear in mind, the low intensity group exercised for five times longer than the high intensity group. 3.5 minutes vs 45 seconds, yet the High intensity group burned more calories.


For busy people, interval training and circuit training workouts are much more efficient to help you burn far more calories in much less time, and burn more fat in the process.

With all this in mind, girls, make sure you are not 100% relying on exercise to “burn fat” in your quest to get leaner. It is a scientific fact that you do need to eat a slight calorie deficit in order to lose fat. Nutrition does have a powerful impact for you if this is your goal. A good mix between your workouts, and your nutrition is really the only way to get what you want.


Media, blogs, and what other people say that you should do, can impact hugely on the choices that you make in regards to our workout routine. Although all the data I have shown you proves that HIIT training can hugely benefit your fat loss, there are other training method that you can supplement your workouts with so that your week is more balanced. You always need to take into consideration your exercise regime, with your lifestyle and what you can and cannot do. 


If you are really struggling to make headway with your own fitness, fat loss and energy balance give our team a call. We would be happy to help you design your week workout. Contact us below or call us on 0208 946 7174.


Siobhan & the Beattitude Team