This has become one of the most popular and overused fitness terms of the past several years. It seems as if almost any fitness class, workout program or equipment will provide “core training” benefits. The “core” most often refers to the muscles that make up the mid-section of the body, including the ever-elusive six-pack. However, it is much more effective to think of the body’s core as the center of gravity and not an actual group of muscles. When we look at how the body functions during upright movement patterns such as walking, lifting an object off of the ground or moving an object from one place to another, we have to consider the fact that any muscle that attaches to the spine, rib cage or pelvis influences movement around the body’s center of gravity.