What do most people think of when they think of Pilates? Abs, Abs and more Abs. However, in actuality there are a lot more muscles that have to work in Pilates. You have a Core Cylinder that is your abdominals, diaphragm, multifidi (deep back muscles) and your pelvic floor. This cylinder has to be working symmetrically for us to prevent pain from occurring in our body. One of the most important muscles is your diaphragm, your breathing muscle. If you are not breathing, then your core is not working efficiently.