A muscle fuel that is extracted naturally from meat and fish, or synthesized in the lab. Once it is in the muscles, creatine combines with phosphorous to make Creatine Phosphate (CP), a high powered chemical that rebuilds the muscles ultimate energy source: Adenosine Triphosphate (ATP). CP powers your muscles for high intensity exercise for short periods only. More CP in the muscle cell translates into a greater resistance to fatigue.