your surgeon will make that decision for you hun, they are the experts so they will decide depending on your shape etc, so its 1 less thing to stress about, there are girls on here who love the gym and have had unders. Im due my ba on 22 may, currently a 32 b (C on a good day lol) im having 290cc overs hopefully to look a full D/DD. i love the gym aswell. its no excerise for 6 weeks after the op xx