There is hardly any other creed in the world of fitness and weight loss that can mess with the so called “fat burning zone”. You are told this zone is the ultimate method to burn your fat and thus drop weight. Good night, fellas…

So what is the “Fat Burning Zone”?
In gyms, on television or sports articles in magazines and anywhere else, it is customary that people trying to lose body fat (often reduced to “weight loss”) are required to perform their cardio workouts at a certain heart frequency (heart beats per minute). This “fat burning zone” usually is set around 120 to 130 heart beats per minute.

This is how “experts” justify the fat burning zone
It is a fact, that your body uses more fat as energy source the more slowly you do your workout. The more intense your workout gets, the more glucose is used instead of fat to provide energy for your activities. So this sounds good? You do cardio at a slow pace (at a lower heart frequency) and fat is primarily used and burnt. Until now, there is nothing wrong in the above explanation, but regarding fat loss, burning fat is not important at all! And all we want is to lose fat!

What do you mean by: “burning fat” is not “losing fat”
Burning fat is just the chemical process happening when your body tries to provide energy for your activities. Losing Fat on the other hand really means dropping weight by eliminating body fat. Your body uses fat and glucose to provide energy, but when using fat (actually fatty acids) it does not necessarily mean sending your body fat to hell.

Prepare for the light…
As everybody already learned at school, the only thing that decides about putting on weight or dropping it is your energy balance. Yes, it is all about calories. Calorie intake is less than calorie consumption - fantastic, you lose weight (by eating less than you need). Calorie consumption is higher than calorie intake - great, you lose weight again (by doing sports, etc.).
Now you know it is all about calories, why in hell should you do slow cardio workouts then?
You didn\’t get it? Here is an example:

Test 1: Non intensive workout
When running at a heart frequency of 120 (the “fat burning zone”), about 75% of the energy is provided by burning fat, 25% by glucose. Because a workout at 120bpm is not very intense, assume you burn like 280kcal in one hour (this applies to a 155lbs person, running at about 5mph).
So about 210kcal are “gone” due to burning fat, and only 70kcal due to burning glucose.

Test 2: Intensive workout
When running at a heart frequency of 160, about 50% of the energy is provided by burning fat and 50% by glucose. Because a workout at 160bpm is much more intensive, assume you burn like 500kcal in one hour (this applies to a 155lbs person, running at about 8-9mph). Because half the energy was obtained by fat burning, about 250 “fat calories” are eliminated.

Now it\’s getting interesting.
Fact #1: As far as only calories (please, please, understand this now and forever) count when trying to lose fat, workout 2 is more than twice as effective as workout 1 (500kcal vs. 280kcal)!

Fact #2: Even if your trainer or whatever “expert” was right (and they are not!), you would burn more fat (which actually is of no interest in a weight loss sense!) when doing the more intense workout number 2 (250 “fat calories” vs. 210 “fat calories”)!
Did you get that? Even if your story tellers were right about “burning fat = losing fat”, you would burn more “fat calories” in the second workout.

Good night my friend. And enjoy your “fat burning zone” workout tomorrow…

This article shows you the importance of calories. For a good weight loss or diet start, try to determine your daily needed calories. You could use this calorie intake calculator provided by the author of this article.
The author is webmaster of the Washboard Abs Website and Blog. Check out this website to find more info about weight loss and fitness issues.