I'm afraid to do chest exercises because they might decrease my bust size.

Chest exercises cannot actually reduce the size of your bust, but they might change its appearance, says trainer Sal Fischera, a spokesperson for the American Council on Exercise in New York City. "The breast is comprised of fat that lies on top of muscle; as the chest muscles become more firm from weight training, they pull on the fat differently," he explains. Flat bench presses target the main pectorals in the middle of your chest, and the muscle development that occurs tends to give women the appearance of a flatter chest, continues Fischera, "so women who are concerned about reducing their breast size should do decline and incline presses." Unlike flat bench presses, decline presses place more emphasis on the lower pectorals at the bottom of the pectoral muscle. "This develops the lower chest muscles and helps to provide a firmer foundation, which may give a lift to the breasts," says Fischera. And incline presses, which work the upper pectoral muscles, "can help fill out the top of the breast." Another key to keeping a full bust is watching your weight loss. If you become too thin or lose a significant amount of body fat, your breast size may decrease along with the rest of you. Maintain a healthy weight and incorporate incline and decline presses into your workout routine no more than three times each week, and Fischera assures that your bust won't become flat or appear to have decreased in size. Also, the lift you'll get from this variety of chest exercises will come in handy down the road when breasts tend to sag. "Your chest muscles are the foundation for your breasts," says Fischera, "so keeping them strong can minimize sagging that may occur later in life."