The Myth About the Fat-Burning Zone

The body does burn a higher percentage of calories from fat in the "fat burning zone" (60-65% of your maximum heart rate). However, at higher intensities (70-90% of your maximum heart rate), you burn a greater number of overall calories, which is what ultimately matters when it comes to losing weight. The chart below details the fat calories expended by a 130-pound woman during "cardio" exercise. 

As you can see, lower intensity workouts will burn half of the total calories from fat stores in your body, rather than from muscle or sugar.  However, high intensity workouts yield more calories burned per minute.  Additionally, the excessive post-exercise oxygen consumption (epoc) is higher after high-intensity workouts, leading to increased metabolism and prolonged breakdown of fat stores. 

So, even though it is harder to work out at higher intensitites, wouldn't you rather make every minute count AND increase your chance of prolonged fat breakdown?  Try it ... create the crave for harder workouts!

	Low Intensity - 60-65% MHR	High Intensity - 80-85% MHR
Total Calories expended per min.	4.86	6.86
Fat Calories expended per min.	2.43	2.7
Total Calories expended in 30 min.	146	206
Total Fat calories expended in 30 min.	73	82
Percentage of fat calories burned	50%	39.85%

Source: From The 24/5 Complete Personal Training Manual, 24 Hour Fitness, 2000