Many women will do just about anything they can to delay or even prevent sagging. But to do that properly, you need to get the sag story straight. Here, the top misconceptions about what makes the girls hang low:Myth #1: Breastfeeding can cause sagging. Not true. According to a 2008 study in the Aesthetic Surgery Journal, breastfeeding is not a risk factor for breast ptosis (another word for sagging). Actually, the pregnancy itself is probably the bigger culprit, says Mary Jane Minkin, MD, a clinical professor of obstetrics and gynecology at Yale University School of Medicine. “Breasts increase in size with pregnancy and stay enlarged with breastfeeding, but they then slowly shrink back down once a woman is done nursing,” she says. “That weight loss and deflation of the breasts can make them sag.“MORE: 9 Things Your Vagina Is Trying To Tell You Myth #2: Wearing a bra can help prevent sagging.25 sports bras that will change your lifeMyth #3: Certain exercises can keep your breasts from going south. Breasts don’t contain muscle, so there aren’t any exercises you can do to specifically target them. But Judy Blume didn’t have it all wrong: Doing exercises for the chest muscles, specifically the pectoralis major muscle located directly underneath the breasts, can help elevate the breasts and give them a perkier appearance, says Deborah Axelrod, MD, medical director of clinical breast services and breast programs of New York University Langone Medical Center. Give these a try.The Unbelievable Reason You’re Short On Vitamin D There’s no data that shows that certain bras such as push-up bras prevent sagging, or that any particular kind of bra can cause sagging, says Minkin. Also, while wearing a bra to bed is totally fine for comfort, don’t expect that nighttime support to keep your girls in perfect shape. Again, there’s no proof that doing so will help prevent sagging. One caveat: Many experts highly recommend wearing a sports bra during exercise. “The constant pull of gravity and the bouncing and movement during running can stretch the breast tissue and possibly lead to sagging, so hold them up with a supportive bra,” suggests Taylor. “Some sports bras are like body armor—they hold the breasts so well there is no movement at all.” (Check out these .)5 moves that target your chestMORE: Myth #4: Small breasts don’t sag.Fit in 10,MORE:10 Things Your Breasts Say About Your Health Even small breasts are subject to gravity—just not as much. “It is true that in general small breasts do sag a bit less than larger ones because there’s less tissue pulling down,” says Minkin. Adds Axelrod, “Whether or not your breasts sag depends on the ratio of breast tissue to fat.” In other words, if you have a high breast density—meaning there’s more breast tissue compared to fat—your breasts will be less likely to droop than if you have a low breast density, with more fat than breast tissue. (Looking for ways to get in more exercise but you’re seriously short on time? Check out  our super-effective workout DVD.)  Myth #5: There’s nothing you can do to prevent sagging. While sagging is inevitable for many women, you can take steps to at least minimize it. For instance, the study in the Aesthetic Surgery Journal found that a high BMI and a history of smoking were risk factors for breast sagging. Also, avoid yo-yo dieting. “If a woman gains a lot of weight, her breasts will stretch out just as the rest of her skin will,” says Minkin. “However, if she then loses that weight, she’ll be left with the extra skin, which just sags because it no longer has all that tissue holding it up. Always maintaining a healthy weight will likely help.”