We've all heard that you can't rely on your bathroom scale to gauge the real results of your diet or exercise program. The bathroom scale simply cannot tell the difference between fat and muscle. Many of us also know that 'bio-electrical bodyfat scales' and 'caliper tests' offered at many health fairs and clubs have a very high error margin. A simple tape measure and a mirror are often better than such errant and misleading numbers.
Keeping your body composition in check allows you to adjust your program appropriately. Eliminate wasted time on programs that are not working. If your body composition is already in your target range, great! Now you can use regular composition tests to see that it stays there and catch the small changes before they become difficult ones!
When an accurate method of body composition testing is used, it tells the real story. Many people can be of the same height and weight, however range from very lean to dangerously over-fat. It all relates to how much of your body weight is muscle. Muscle is heavier than fat and takes up far less space in your body.