Don’t get me wrong, I see the logic, you want to lose fat, you gotta burn it. However it really does amaze me that this myth is still ripe in the fitness industry. It scares me is that there is a lot of trainers who are still peddling this line to their clients.
Scientifically, it’s correct. There is a zone where you burn more fat. Here’s why. At a lower intensity, your body requires less quick energy (which comes from carbohydrate), and it can utilize slower burning energy (which comes from fats). The problem lies in the fact that weight loss is simply one thing. Energy in is less than Energy out. You have to expend more energy than you put in your body to lose weight. It’s an equation, and quite a simple one. Sure you will burn a higher percentage of fat if you work at a lower intensity, but you will burn a lot less calories than you would if you were working out at a higher intensity. If weight loss is your goal, total amount of fat lost will be lower with a low intensity workout. You have to exercise for a long time in your ‘fat burning zone’ to reach the same amount of calorie expenditure as a short high intensity session.
But how does my fat get burnt?
It is a little hard to understand, it seems so simple, want to lose fat, then you want to burn more of it. Try and think of it this way…your fat stores will be broken down and transformed into carbohydrates when your body needs fuel anyway, so it is irrelevant which type of calorie you are burning. Your fat calories will still get used. The key is to expend more calories. Working at a higher intensity will only cause you to use a lower percentage of fat; percentage is the key word here, what we are after it total. Because you are burning more energy in total, you will still use more fat calories. The bottom line is, if you have a limited time frame, a short high intensity workout will give you more benefits. Save some time and get better results.