Creatine is a natural substance produced by the liver, kidneys, and pancreas.
Eating meat and fish also provides the body with creatine. It is stored primarily in the muscles. Creatine enables the muscles to sustain maximal contractions and may allow quicker recovery between exercise bouts. When creatine supplies in the muscles are depleted, the body relies on carbohydrates for energy during anaerobic exercise. Creatine supplementation is promoted as a method of increasing the amount of creatine available to the muscles, thus decreasing the utilization of carbohydrate for energy.