Others have passed this exercise-for-weight-loss way before, but Gutin offers a competent and helpful addition to those guides. Recent research shows that the body's remarkable ability to adjust to a low-calorie diet without losing weight is the reason that traditional reducing diets fail or are painfully slow after initial success. Investigators have found, however, that this protective mechanism can be thwarted by only slightly lowering food intake, and greatly increasing energy output. Gutin clearly explains these findings--and then focuses on the exercise component (though he does make basic recommendations on diet too). How to start out (which exercise to choose, what level to start working at) and how to keep going are well covered, as are the other benefits of such a program (including cardiovascular health and the feeling of well-being that's ""The High-Energy Factor""). Kuntzleman (Diet Free) and Katahn (The 200 Calori'e Solution) cover the same ground; but this is no less worthy.