Fat burning zone and cardio zone

Interestingly enough the next post I read had information regarding common exercise myths and had this to offer:

THE MYTH: Exercise in the fat-burning zone

THE TRUTH: The "fat-burning zone" lies between 50 and 70 percent of your maximum heart rate. When you exercise at this low intensity, your body draws energy from fat. As your heart rate goes up, more energy comes from carbs. So it seems logical that to lose fat you should keep your heart rate low, says Jason Karp, Ph.D., owner of Runcoachjason.com. But that's not the case.

"Running at higher intensities causes you to burn a lower percentage of fat calories in favor of carbs," says Karp, "but you use more total calories." And that's the key to slimming down. Plus, since you torch more total calories, the absolute amount of fat burned actually increases, too. So it pays to pick up the pace.

Of course, lower intensity exercise still has its place. Long, slow runs build aerobic fitness and endurance. But to kickstart a pokey metabolism, you need intensity. Karp suggests interval training (condensed runs that mix in intense efforts with recovery) because studies have found these workouts burn more calories during and after exercise (see "Torch Calories," for Karp's interval workout). "It also cuts down on boredom," he says, "which makes it more likely you'll stick with your program."


Just thought I'd pass it along :happy:

I do my best to do at least part of my cardio workout in the fat burning zone. Now, there are different way to calculate target HRs and percentages and everything, i can put those at the end of this post. Hopefully i can explain the difference in HRs...Basically when ends up happening is when your HR gets past a certain point, you are simply stressing the cardiovascular system, so instead of going to your fat storage for the energy it needs, it uses other energy stores that will metabolize the energy faster. The cardio system has a lot of feedback and is basically for the most part the first thing the body listens to. So the heart is saying, i need energy to pump all this blood, and the body is saying, okay i'll get you some quick energy - which doesn't come from fat.

Now, if you workout at a lower intensity, your HR will not reach that point in which it needs the quick energy, and it will use your fat storage for the energy it needs. However, because the fat storage takes longer to get to, the workout has to be a long duration in order for that fat storage to "melt" and provide the energy.

Of course the harder you work, the more calories you burn, which if your other energy stores are already depleted, fat will be burned instead (the basis behind low-carb diets)... of course if you are looking for more of a calorie burn, the higher intensity will make sense.

i hope that helps at least a little bit. Now the best way to find the target HR is with the following formula...

First, Calculate the Maximal Heartrate (HRmax):
General Population: 220 – age
Individuals older than 40: 205 – ½ age

Then, calculate the Target Heartrate:
(HRmax- HRrest)(%) + (HRrest):

So, for example, I am 24 years old, and my resting HR is 60 beats per minute.
My max HR is 220-24 ... 196

My target HR, if I wanted to workout at a 50% intensity would be:
(196 - 60) (0.50) + 60 = 128


If you want to simplify it, most machines (bikes, ellipticals, treadmills) at the gym have the "Fat Burn" workout option, and you can input your age and it will tell you your HR zone.

The Runner's World article on weight loss myths (cited in another recent post) addresses your question. Here's the answer, which sounds logical to me:

THE MYTH: Exercise in the fat-burning zone

THE TRUTH: The "fat-burning zone" lies between 50 and 70 percent of your maximum heart rate. When you exercise at this low intensity, your body draws energy from fat. As your heart rate goes up, more energy comes from carbs. So it seems logical that to lose fat you should keep your heart rate low, says Jason Karp, Ph.D., owner of Runcoachjason.com. But that's not the case.

"Running at higher intensities causes you to burn a lower percentage of fat calories in favor of carbs," says Karp, "but you use more total calories." And that's the key to slimming down. Plus, since you torch more total calories, the absolute amount of fat burned actually increases, too. So it pays to pick up the pace.

Of course, lower intensity exercise still has its place. Long, slow runs build aerobic fitness and endurance. But to kickstart a pokey metabolism, you need intensity. Karp suggests interval training (condensed runs that mix in intense efforts with recovery) because studies have found these workouts burn more calories during and after exercise (see "Torch Calories," for Karp's interval workout). "It also cuts down on boredom," he says, "which makes it more likely you'll stick with your program."

I wish I could find the post I did about a month or two ago regarding my Polar F6 breaking down my calories burned into fat percentage, etc. I essentially got told that it didn't matter, to ignore that number. The bottom line is to build muscle that burns fat. You gain muscle by burning fat, increasing your metabolism, etc. etc.

I tried to stay in the low HR range, which according to my HRM is fat burning area...well I felt like I was barely moving on the elliptical when I did that. Once I posted my questions and got a response, I ignored that breakdown of what cals I burned were "fat cals" and went to town. I've not had any issues gaining muscle or slimming down and have consistently kepy my HR in the mid-high to high range every time I work out.

Ha! I found it:
http://www.myfitnesspal.com/topics/show/78793-hrm-fat-calories-vs-regular-calories-burned?hl=Polar+F6+HRM#posts-1078179