Achieve a strong overall core and you’ll achieve a strong overall you. Recent trends in the exercise and fitness industry are peppered with the phrase “core strength.” What does it really mean? Core refers to the muscles of your abs and back and their ability to support your spine and keep your body stable and balanced. Achieving a strong overall core will allow you to reduce back pain, have better balance and get strong, flat abs. There are four key layers of the abdominal wall. Most people think that their abs are separated into lower and upper portion, but in reality it is all one muscle group that works synergistically to rotate your torso, flex your spine and stand tall. The most superficial layer — Rectus Abdominis — is on top and closest to your belly button. This layer is the sought-after six pack that everyone wants to have visible.