Developing and toning the chest muscles, as with any muscle group, requires two phases--weight (fat) loss and toning or muscle development.

The first phase, losing fat, is important in order to reveal the toned muscles and improve your overall health and appearance. A low calorie diet with at least 30% of the calories from protein will help you develop more muscle while losing fat. Keep in mind that no diet can target any body area for weight loss. As you lose fat, the body depletes its fat stores from all over the body. If you want a firm, toned, well-defined chest, you will also end up with a slimmer body for your effort.

The second phase in developing and toning your chest is exercise. Specific exercises target the pectoralis major (the largest chest muscle). These muscles are used to draw your arm across your chest and for pushing things like lawnmowers and carriages. These large muscles also help in creating a more toned appearance for women's breasts since they are the underlying muscle. If the muscle is not toned, breasts tend to sag more than if they are toned. Note that there are no exercises that can undo all of the effects of child bearing, nursing, sagging, or just plain gravity. But, conditioning and toning the large chest muscles will improve your overall appearance.