When going into the gym, trying to grow a larger backside. You need to know that there are 3 muscles you need to work on to enlarge your rear end. They are the Gluteus Maximus, Gluteus Medius, and Gluteus Minimus. The appearance of your butt has to do with how much fat is covering your glutes. So please note, if your legs and/or thighs are on the smaller side. A bigger ass may not be in your future. However; you can still sculpt your gluteus to a better liking. Rather you are on the fuller or leaner side, these tips should help you gain your best butt.