If you are a woman, chest size, at least PARTLY, probably is genetic, through your Mother's DNA. There is *no exercise* that can just "target" one area of the body for it to become smaller. Depending on what the "size issue" is, you may do best to see a good doctor. (More than a few women have mammary-size issues that negatively affect their overall health, and give real back pain, make it hard to exercise, etc. Hopefully, that's not you.) You're not alone. Good luck!

The skinnier u are the more u won't have boobs.