The Fat Max Zone refers to the intensity level of exercise that burns the maximum amount of fat.
Exercise Intensity Versus Fat Burning
In a recent study conducted in England, at the School of Sport and Exercise at Birmingham University, scientists have identified the Fat Max Zone. Using 25 moderately trained individuals, in both graded and constant exercise programs, researchers have concluded that exercising too intensely will cause fat burning to markedly drop.
Fat oxidation, or fat burning, is something the human body does quite naturally. Stored body fat, along with the carbohydrates we consume, become our main source of fuel, or energy. Fortunately, the human body is very good at burning fat over a large range of exercise intensities. However, if you train too intensely, sugar will become your main source of energy, not fat.
So what's the right intensity to activate all this fat burning?
Scientists involved in the study used maximal oxygen consumption, or VO2 Max to determine exercise intensity. VO2 Max is a way of expressing how fit you are by gauging how much oxygen your body can use at the cellular level.
For the best aerobic, or fat burning workout, the traditional, recommended range is from 50 to 85 percent of VO2 Max, when using the heart rate reserve formula found below. This is not to be confused with a simple percentage of your maximum heart rate.
Researchers involved in this Birmingham study found that the Fat Max Zone (where the most fat was burned) was actually reached at 55 to 72 percent of VO2 Max. This represents a substantially narrower range, especially on the high end (less a whopping 13 percent), than what was previously accepted. Possibly an even more important finding -- at levels above 89 percent, fat burning all but ceased.
The Fat Max Zone
(as measured by the heart rate reserve formula)
1. Calculate estimated maximum heart rate (MHR)
using the following formula:
220 minus age = MHR
Estimated MHR for an average 30 year-old would be:
220-30 = 190
2. Next, determine resting heart rate (RHR):
Take your pusle for 1 minute white at TOTAL rest:
(Typical RHR = 70)
Subtract RHR from MHR:
190 - 70 = 120
3. Calculate percentages:
55% of 120: = 66
72% of 120: = 86
4. Add RHR (70) back into to both numbers:
66 + 70 = 136
86 + 70 = 156
The Fat Max Zone for an average 30-year-old, would between 136 and 156 beats per minute. Grab a pencil and paper and calculate your own Fat Max Zone.
Without the need of a trainer, and by using the above formula, you can make sure your aerobic regimen is working towards increasing V02 Max (and your ability to burn fat), while at the same time taking place in the Fat Max Zone.
Aerobic exercise should be repeated about 3 or 4 times per week, for a period of at least 15 to 20 minutes to achieve optimum results. Be sure to pay attention to how you feel, as well as how you're breathing, during exercise.
As a general rule, you shouldn't feel overly fatigued or winded during aerobic exercise, and you should be able to speak at least three words (or syllables) without taking an in-breath.
Michael Stefano is author of The Firefighter's Workout Book, as well as a twenty year veteran of the New York City Fire Department. His simple, yet highly effective training programs are used by firefighters across the country, and the general population alike.
Posted September 2003
Updated November 2010
