XFW 6111 -- Cut to the Core 6 Contact hours (Offered as needed) Twenty minute core workout for improving overall conditioning of the core. The core is a collection of muscles which stabilize and move the spine. Close to the spine and deep inside the abdomen is the inner core, which is comprised of the diaphragm, pelvic floor, multifidi, deep cervical flexors, and transverse abdominus. These strange-sounding muscles engage first during movement or breathing to protect the spine. The class starts with a 5 minute warm up, 20 minutes or core strengthening and a 5 minute stretch, cool down.