…by Mary Pearsall

At one time or another, you have almost certainly stepped on a scale to check your body weight. But relying on the scale to tell you if you\’re at a healthy body weight can be frustrating. Understanding what the scale does and does not tell you will help you keep the scale\’s information in perspective.

The difference between fat and muscle.

A scale simply measures your total body weight in pounds (or kilograms). It does not measure how many of those pounds are muscle, bones, blood, etc. and how many are fat. Exercise physiologists call this ratio you body composition, typically referred to as percent body fat.

Focusing on the number on the scale is problematic because you don\’t know how many pounds are from fat and how many are from muscle. You may have heard that “muscle weighs more than fat.” That\’s not true. A pound of muscle weighs the same as a pound of fat: one pound. However, fat and muscle differ in an important way – muscle is much denser than fat. Think of it this way: Muscle is like a brick. Fat, on the other hand, is like cotton balls. It takes far more cotton balls than brick to make a pound. So a pound of fat takes up more space on your body than a pound of muscle.

Making changes.

Let\’s examine how judging yourself only on scale weight can be misleading. Let\’s say you are sedentary and decide to start a fitness program that includes moderate to vigorous aerobic exercise for 30 to 45 minutes four to five times per week. If you combine this workout schedule with a sensible, adequate-calorie diet, research suggests that you could potentially lose one to two pounds of fat per week.

Your new fitness lifestyle could help you lose, say, 10 pounds of fat in the next three months. In addition, your strength training program could help you gain about three pounds of lean muscle weight, a very positive change. If you used the scale as our only reference point, you might be tempted to think your new lifestyle wasn\’t working very well, because you\’d see only a seven-pound weight loss. But rest assured that you would have make truly positive changes.

Because of fat\’s low density, you\’d probably see the 10-pound loss as smaller circumference measurements around your stomach, hips, and thighs. That\’s why paying attention to the way your clothes fit is generally considered a better way to assess your progress than focusing on the scale.

If you went just by the scale\’s number, you might be tempted to skip strength training, and that would be a shame. Additional muscle tissue not only helps you become stronger, making daily activities easier to accomplish; it also has an extra long-term advantage: Muscle tissue expends calories all day long, even when you are at rest. Over the course of a year, a few added pounds of muscle can help you burn thousands of additional calories.

Getting Real About Weight

Keep in mind that you body weight can fluctuate by several pounds over the course of a day. This is especially true if you exercise fairly vigorously. The fluctuation is due to changes in the amount of water in the body. If you weigh yourself before and after an exercise session, you might find you\’ve lost a few pounds. It\’s just water loss.

Likewise, if you weigh yourself right after a big meal, the scale might show you\’ve gained weight. Additionally, women often show weight fluctuations in relation to hormonal changes during their monthly menstrual cycles. Checking the scale no more than once every week or two is usually best.

How much should you weigh? Health and fitness professionals frequently debate this question, but there\’s not clear cut answer. If you have not risk factors, such as high blood pressure, high cholesterol or Type II diabetes, and adopt an active lifestyle that incorporates regular exercise and sensible eating, the weight you achieve over time will likely be your healthy weight. Patience and persistence are the keys.

Accurately measuring changes in percent body fat is an excellent way to track your exercise progress. To find out your percent body fat, consult a qualified fitness professional. He or she is likely to use either a skinfold caliper or the circumference measurement technique, both common methods.