Ask the Trainer

Q: If your goal is to lose body fat, shouldn’t you always stay in the “fat-burning” zone that’s displayed on the cardio machine?

A: The short answer is no. If you have no medical restrictions, working out at a higher level of intensity is better for a number of reasons. I’ll explain why a little later, but first let’s look at where the idea of the fat-burning zone comes from.

We basically have three substrates, or calorie-containing energy sources: carbohydrates, protein and fat. There are more than twice as many calories in fat as in the other two and carbohydrates are, by far, the body’s preferred source of energy.

That’s important because severe restriction of calories or carbohydrates over a long period of time will compromise your ability to exercise and hamper your fat-loss efforts because your body will become more calorie-efficient, using less and storing more until you correct the imbalance.

The idea of the fat-burning zone comes from the slightly interesting but not very useful fact that the body uses a modestly higher ratio of fat-to-carbohydrates in the 50 -75 percent maximum heart rate range (MHR) than it does above or below that range.

What makes the principle not only useless but also misleading is that you burn a great deal more calories at 85 percent or more of your MHR, more carbohydrate calories and more fat calories, even though the ratio of fat-to-carbohydrates goes down slightly at the higher intensity level.

Imagine you collect coins. Gold coins are worth more than coins made of other metals, which all are about the same value, so you want as many coins and as many gold coins as you can get for the price. One dealer will sell you a set of 60 coins, of which half (30) are gold. Another dealer will sell you, for the same price, a set of 100 coins with a slightly lower percentage (40 percent, or 40) of gold ones.

The second set gets you more coins and more gold coins. So which set are you going to buy?

Of course, medical restrictions, fitness level and training comfort preferences are important issues to consider when deciding how intensely to exercise.

But don’t be fooled by the “fat-burning zone” fallacy. The more calories you burn, the more fat you’ll drop. Just make sure you’re eating enough high-quality calories and getting enough rest to support your more robust training program.

Then go burn some fat. And remember — the hotter the furnace, the more you’ll burn.

For more information, contact Dan Taylor at http://trivalleywellness.com.