So much of the exercise we do, such as running and cycling, focuses on the lower body. Not much attention is paid to the trunk, or core of the body.

It is the muscles of the core -- the abdomen, chest and back -- that stabilize the rest of the body. Think of your core as a strong column that links the upper and lower body together. Having a solid core creates a foundation for all activities, and is especially important when you add a heavy load, such as weights to your workout.