Muscle trimming, the "floor work" of aerobics classes, is intended to increase muscle tone and improve body contours. Beware of promises from books and instructors that this activity will firm up sagging bodies, make bulges disappear, and melt away "cellulite," the ugly fat deposits that no beautiful person can afford to be seen with. Would that all those leg lifts and abdominal crunches could accomplish such miracles, but the truth of the matter is otherwise. Fat disappears only by gradual weight loss through permanent changes in diet and general attention to all the principles of health stressed in this book. Even so, this sort of exercise can make you feel good and like your body more.
Abdominal exercises are a type of muscle trimming, but I put them in a special category because they may help prevent lower back trouble. For example, sit-ups can strengthen and balance the muscles that support the spine. Some male bodybuilders work at developing boardlike abdominal muscles. This is not healthy if the muscles cannot relax, because such extreme tone may interfere with the function of the digestive organs. The abdominal muscles should have good tone but also should be soft and yielding, a principle taught in most of the martial arts. I recommend moderate, sensible abdominal exercises for those who have had back trouble, abdominal surgery, or multiple pregnancies.
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