You jump onto your favorite elliptical or treadmill, and you often see a graphic indicating “fat burn zones” and “cardio zones.” At first glance, it may appear that you burn more fat working at a lower intensity (55%-65% of your heart rate maximum) than you would working in a cardio zone (75%-85% of your heart rate maximum). This sounds like a good deal—doing little work to burn more fat—however, this information is misleading.
Exercising to lose weight comes down to calories burned. It is true, that in the fat burn zone you will burn more stored fats as your main energy source. Yet your total caloric burn during this time is minimal. When you exercise in a cardio zone, you will burn more glycogen, or stored carbohydrates as your main energy source, using less fat, nevertheless, your total caloric burn is much greater. Remember, calories burned is what results in weight loss.
Depending on the intensity of your activity, your body may have an “afterburn” effect. Exercising at low intensities, the fat burn zone, you have no afterburn. This means once you are done exercising, your body does not continue to use stored energy and burn calories. Exercising at higher intensities shakes up your metabolism and burns more calories, and has a high afterburn. You are still burning calories after you are done exercising!
Choosing exercise methods such as HIIT (high intensity interval training) and Tabata (a variety of HIIT) will provide the largest impact on calories burned, during and after exercise. Always consult with your physician before beginning an exercise program, and work with a trainer to help choose the best exercises and methods for you.Set up a Free Fitness Consultation
By Melissa Radmer, CPT, Group Exercise & Fitness Director at Elite Sports Club-West Brookfield