We know that exercise is good for our health for many reasons, including reducing the risk of breast cancer. Making sure that we are wearing the right "gear" during exercise is also important-not for breast cancer prevention but to prevent other damage to our breasts.
Any kind of vigorous exercise usually means that our breasts and other fatty areas of our bodies will have to endure a lot of bouncing. If you are wearing a bra that doesn't encompass the entire breast mound, that up-and-down action can result in premature stretching of the Coopers ligaments.
Because a badly fitting bra is not supporting the breast and surrounding muscles properly, your breasts might begin to droop more and become painful both during and after your workout.
The solution is simple: Wear a properly fitting bra, ideally a sports bra that fits snugly enough to keep your breasts close to your chest and to limit the amount of bouncing during vigorous exercise. This is especially important for joggers.
On the other hand ... be careful not to get a sports bra that fits so snuggly that it takes your breath away! Your bra should not only fit comfortably but should also pass the bounce test: You jump up in the air but your breasts stay right where they belong.