Creatine is a protein molecule that is stored in muscle.
For activities lasting 10 seconds or less, ATP is the energy source for the muscle. It has been shown that muscular fatigue is related to phosphocreatine depletion in muscle, and that creatine supplementation can enhance the levels of both creatine and phosphocreatine in skeletal muscle. Creatine is available in powder form or capsules as well as in bars, gels, candy and gum. Creatine is an energy-producing substance naturally found in the body. Research studies have indicated that oral ingestion of the supplement creatine monohydrate has a beneficial effect on short-duration, repetitive bursts of intense exercise such as that experienced in rowing, running, cycling, swimming and resistance training.