Heart Rate to Burn Fat: Myth Busted!

One of the biggest myths in the fitness world today is about your heart rate to burn fat, and it drives me a little nuts.

This insane “fat burning zone” myth is something that so many people have been led to believe is keeping people from burning fat as fast as possible.

There are two main reasons that this craziness has endured. The first is the “fat burning zone” label that constantly shows up on cardio equipment. The second is because people want “easy” workouts and they are willing to sacrifice hours just to be able to not have to work hard. This is the mentality that most people have and sadly this has led to so many people being disappointed in their results (or the lack thereof).

Let me stop right here and remind you – there is no magic bullet for burning fat. If you really want to burn fat, you have to be willing to work at it. Until you realize that, you’ll keep chasing the next big thing, and the only thing that will get thinner is your wallet.

The “heart rate to burn fat” theory is that your body uses a greater percentage of calories from fat as fuel at relatively a relatively low heart rate. People, of course, jumped all over this like white on rice sitting on a paper plate buried in a snowstorm.

The key word there, however, is *percentage*. As it turns out, during low-intensity exercise approximately 60% of the calories burned come from fat, while high intensity exercise generally burns about 35% of calories from fat (source). If we stopped there, it seems clear that we should do the long slow all of the time. It’s not quite that simple, though.

Remember the fundamental formula for fat loss… total calories *always* matter.

Let’s Look at a “Heart Rate to Burn Fat” Example

Scenario 1: Let’s say you are sitting on the couch watching television for half an hour. During this 30 minute period, you burn 50 calories, 85% of which come from fat. That means that you have burned about 42.5 calories from fat specifically.

Scenario 2: You do some low intensity exercise for 30 minutes with your heart rate is in the “fat burning zone.” You quadruple your calorie burn to 200 calories, 60% of which come from fat. That means a total of 120 calories from fat.

Scenario 3: You do high intensity exercise for 30 minutes. Your calories burned jumps up to 400 calories. However, in this scenario, you on burn 35% from fat. How does that shake out in terms of total calories from fat specifically? Drum roll…

140 calories from fat.

This difference only gets wider the longer you exercise. And this doesn’t take into account the extra boost in post exercise metabolism following high intensity exercise. When you take that into account (we will dig deep into this phenomenon, called EPOC, in a future post), you’ll never think about the “fat burning zone” again.

Put This New Knowledge Into Practice for Faster Fat Burning

The best way to do high intensity exercise is through something called, High Intensity Interval Training, or HIIT.

HIIT will be one of the few things that will be able to change your life almost instantly. You will begin to realize that your body is actually capable of working hard and those hour long strolls really are nothing compared to an intense 20 minute workout using high intensity interval training.

This type of workout is very convenient because you do not need any kind of equipment to be able to reap the benefits. All you really need is the right mentality and some exercises to do at home and you are ready to get your heart beating. The trick is to choose an exercise that will get your heart beating… biking or running (my choice) are perfect for this.

The basic theory behind HIIT is that you will be working really hard for a short period of time and then taking a break. This is then repeated for a certain amount of times for about 15 minutes. This is essentially all you really need to do and definitely will get your heart rate to burn fat throughout the day and not just during the workout.

If you are serious about trying to burn fat with this workout, you have to realize that it can be taxing on the body and so it is not really a good idea to do this type of workout in the morning on an empty stomach. This is best after a weight lifting program to be able to burn some excess fat after you have lifted weights. A program like Turbulence Training combines weight training and HIIT perfectly.

Compared to 45 minutes of moderate exercise, a 15 to 20 minute workout will both save you time and give you better results. Focusing on your heart rate to burn fat is not really a bad thing as long as you know you are pushing your body pass the mythical “fat burning zone”.