By Eric Franklin, of The Franklin Method
The classic core muscles are the diaphragm, the abdominals, the pelvic floor and the deeper layers of the lower back muscles. You can stabilize your core with your glutes and other peripheral muscles. Natural movement can be sufficient to train your core. You can get a workout from every day things like walking and even breathing.
Watch this free video lesson to learn more about how you can strengthen your core with every breath you take and every step you make.