Exercise & Weight Loss

Below is an excerpt from Part Two of

The 2004 Multi-Diet

by Anderson A. Anonymous, M.D., Ph.D.

Background

When was the last time you took the stairs two at a time—just because you felt like it? When was the last time doing a dozen knee bends actually felt good? Well, if you’re like me, chances are it was a very long time ago—if ever.  But if (perchance) you can remember the feeling, wouldn’t you like to get it back?

Feeling good is what “quality-of-life” is all about—and also what losing weight is all about.

For exercise physiologists, exercise is mainly about techniques to increase the body’s ability to produce energy for moving around. For dieters, it is additionally about how to make sure that this increased energy production results in less bodyfat. Dieters have learned (usually the hard way) that simpleminded exercising doesn’t reduce bodyfat, except by accident and rarely for long.

As with everything else on the Multi-Diet, turning exercise into less bodyfat involves making sure you do certain things and don’t do other things.

Exercise Metabolism

As we discussed earlier in more on… energy metabolism & storage, the muscles have “favorite fuels” which depend primarily on the intensity and duration of what they’re doing.

Basically, these fuels are:

1. Carbohydrate—for high-intensity, short-duration exercise (e.g. power aerobics)
2. Fatty acids—when at rest or for low-intensity, long-duration exercise (walking, jogging, working, etc.).
3. Protein—but the amount is usually considered to be no more than about 5%–10% of the total under ordinary circumstances.

Carbohydrate (which is stored as glycogen) is the body’s most efficient fuel in terms of oxygen consumption. This means that the heart and lungs don’t have to deliver as much oxygen in order to get it burned for energy—a situation which has obvious physical advantages. On the other hand, the body can’t store very much glycogen, so glycogen tends to be conserved until it’s really needed (like for climbing trees faster than saber-teeth tigers. )

Keeping glycogen storage capacity minimal also has some physiological advantages, because storing energy in glycogen form takes up a lot more space than storing energy as fat.. If you stored the same amount of energy in glycogen form as you do in fat form, you would be about five times as heavy as you are now.  (The saber-teeth tigers wouldn’t even have to run to catch their dinners. )

In any case, at low-to-moderate exercise-intensity levels, when the heart and lungs have lots of excess capacity to deliver oxygen, the muscles will use fat for fuel and can go on using it for long periods. Conversely, at very high exercise-intensity levels, when the heart and lungs may have difficulty keeping up with the oxygen demand, the muscles switch over to using mostly carbohydrate, but run out of it fairly quickly. Naturally, we dieters want to keep our exercising in the “fat-burning” low-to-moderate intensity range. (We thank God and evolution for these small favors. )