Continued from Natural Sources of Creatine.

Creatine increases recovery and slows the likelihood of fatigue, so supplements allow you to work out longer. Investigations into the tissue level effects of oral creatine seem to show several changes.

Supplementation can cause an approximate 20 percent increase in muscle phosphocreatine stores, quicken the replenishment of phosphocreatine during recovery, and buffer lactic acid.

Less than 100 percent of dietary creatine is absorbed by the small intestine. Extra creatine not used by the muscle is excreted as creatinine from the body. Thus creatine is not degraded to creatinine in either the stomach or gastrointestinal tract, nor is it passed through the intestinal tract without absorption by the intestines.

Creatine monohydrate supplementation may increase the amount of creatine reserve up to 140,000 to 150,000 mg. However, excess creatine is lost in the urine.