change in bodyweight, it is actually a 20-pound change in body composition. The muscle loss adversely affects our physical function and personal appearance. Perhaps more importantly, it results in a reduced metabolic rate that facilitates fat gain. This is because every pound of muscle loss reduces our resting metabolism by at least 35 calories per day. Assuming we eat approximately the same amount of food, calories that were previously used for muscle maintenance are now placed into fat storage, resulting in creeping obesity. Excess body fat is a major health risk associated with many medical problems including low back pain, type II diabetes, various forms of cancer, high blood pressure, and heart disease. Most people understand this, and half of all Americans are presently on low calorie diet plans to reduce unwanted fat. Unfortunately, dieting alone has a dismal record of success, with over 90 percent of dieters regaining all of this fat weight within one year. Even worse, about one-quarter of the weight lost through dieting is muscle, further reducing this vital tissue and resting metabolic rate. No wonder a return to normal and necessary eating behavior results in fat regain. Because the deterioration in body composition is a two-fold problem (too little muscle and too much fat), restoration of desirable body composition requires a dual solution (muscle replacement and fat reduction). Obviously, regular exercise is essential for replacing muscle tissue. However, only strength training is effective for this purpose. ]