Fat burning zone vs cardio zone

Everytime I step onto a cardio machine (which actually isn't all too often but....), I shake by head at the preset "fat burning" and "cardio training" zone buttons.

The fat burning zone is characterized by exercising at a lower intensity - walking or a light jog, not letting your heart rate go above 40-60% of your max. The cardio zone is an increase in heart rate percentage to 70-85%. So, how is it then, that when you are working harder you are actually "burning less fat?"

In actual fact, you are burning more fat when you are exercising at a higher intensity, the disconnect comes in the percentage of fat vs. carbs you are using when exercising at the two different intensity levels. When you are walking or jogging, your body does burn a higher amount of calories from fat. However, in the 'cardio' zone, you burn an overall higher amount of calories - meaning an overall higher amount of calories burned from fat.

Here is a chart to better explain taken from http://exercise.about.com/cs/cardioworkouts/l/aa022601a.htm




Low intensity exercise of 130 lb woman:
Total cal expended per minute - 4.86
Fat expended per minute - 2.43
Total cal over 30 min - 146
Total fat in 30 min - 73
%of fat burned - 50%

High intensity exercise of same 130lb woman -
Total cal expended per minute - 6.86
Fat expended per minute - 2.7
Total cal over 30 min - 206
Total fat in 30 min - 82
%of fat burned - 39.85%

While low intensity cardio has its place, if weight/fat loss is your goal, I believe that exercising at a higher intensity will help you to achieve the results you want.


Nutriton Tip - Drink 1-2 glasses of water 5-10 minutes before eating a meal. Water will help you to feel more full and reduce the risk of overconsumption.

Fitness Tip - Try a Tabata for high intensity cardio. 20 seconds of as many reps of an exercise as you can (light-no resistance), 10 seconds rest - repeat 8X.

Song - O.P.P. - Naughty by Nature