An unusual side-dish, not spotted on most workout menus. The "pelvic floor" is a funnel-shaped muscular structure that sits at the very base of your core. These muscles not only hold certain internal organs in place, they also aid in bladder control, sexual function, and they shape the abs in a concave fashion. Pelvic Floor exercises are integral to proper Pilates form, and are recommended by many health professionals as a part of a comprehensive fitness routine.