What is the fat burning zone? Should I run more slowly to lose fat?
You may have heard the claim that you should run more slowly to burn more fat. My local gym has signs suggesting that if you want to burn fat, you should exercise in a “fat burning” heart rate zone. This idea is based on a misunderstanding of the science. It is true that when you exercise at a lower intensity, your body is able to draw more of the energy directly from fat. But it is not correct to conclude that exercising at this lower intensity will result in your having lower overall body fat. There are two reasons why the claim about a “fat burning zone” is wrong. * First, it does not matter where the fuel comes from while you are exercising; in the end (ie later in the day) your body will replenish and rebalance your energy stores. So a calorie surplus will always end up increasing your body fat; and a calorie deficit will always end up reducing your body fat. The source of fuel while you are exercising is irrelevant. * Second, what matters is the total amount of calories you burn;
