Most diets just concentrate on the nutrition side of things, but exercise is often a great way to accelerate your fat loss as well. If you look at something like this Burn the Fat Feed the Muscle guide then that covers both the nutrition and the exercise part together. That is important because then the diet is adjusted to compensate for your increased physical activity. If you throw in exercise with other diets like very low calorie diets, then you might find yourself feeling weak after you exercise or even fainting. Before you start any new exercise program of course you should consult with your doctor.