Exercise increases your metabolic rate – not only during the exercise, but also for a period of time afterward. The indisputable long-term key to fat loss is exercise. The reason: this is virtually the only proven way to increase metabolism and boost calorie burn. Working out regularly and vigorously both preserves and builds muscle mass, which even at rest burns nearly twice as many calories as fat tissue. Dieting without exercise, on the other hand, only signals the body’s many different physiological safeguards to turn on, which slow down the metabolism and protect body fat reserves against possible starvation. These things are much more powerful than the mechanisms we have to protect ourselves from obesity. Fortunately, there is a proven way to lose fat and permanently keep it off. The answer lies in working with our body systems and chemistry – through diet, exercise, and positive thinking.