CrossFit Atlanta Newsletter
News & Fitness Information from CrossFit Atlanta
February 3, 2007 - Vol 1, Issue 1
We are often asked how short, intense workouts can provide the better fat loss benefits than traditional long duration, low power workouts in the so called "Fat Burning Zone." Tony Leyland of the University of Vancouver takes a stab at answering that question in the February 2007 CrossFit Journal in an article entitled, "The Myth of the Fat Burning Zone."
We've all seen the charts on cardio machines and on the walls of traditional gyms that purport to show that the most effective fat burning exercise occurs when the heart rate is in the range of 55% to 65% of maximum, in other words when we are execising at a mild to moderate intensity. Such charts bring Mark Twain's aphorism to mind, "There are three kinds of lies, 'Lies, damned lies, and statistics.' "
The chart and the myth are based on research which shows that when we exercise at 50% of VO2 max our body draws about 50% of its energy from stored fat, and that when we go to higher intensity, 70% of VO2 max, we only draw about 33% of our energy from stored fat. All this is true, but the chart and the myth are based on the false premise that higher percentages mean higher totals. The truth is that so much more energy is used in high intensity exercise that more total fat is burned. Put another way, a higher percentage of a small number can yield a lower total than a smaller percentage of a large number. A perhaps more understandable analogy is that 1% of Bill Gates' fortune is way more than 100% of most folk's weatlth.
There is more to this story. Stay tuned.
