Creatine - What Is It Made Of?

What Is It Made Of?

endogenousPronounced en-DAH-juh-nuss; produced within the body., or natural, creatine is produced from three amino acids: arginine (AHR-juh-neen), glycine (GLY-seen), and methionine (meh-THY-uh-neen). It can be found in most of the body's organs. However, the vast majority of it resides within the muscle cells that power the body's movements.

Creatine is part of a complex chemical process that creates and restores adenosine triphosphateAn important energy-carrying chemical, created with the assistance of creatine. (ATP), the fuel that muscles feed on as they contract. In quick movements, ATP converts to adenosine phosphate (ADP), releasing a burst of energy in the process. As Monaco noted in his book, "Normally, muscles contain only enough ATP to provide energy for between five and ten seconds, depending on the amount of effort required for the activity. Then, the muscles need creatine to make more ATP."

About two-thirds of the creatine in the body is creatine phosphate. This chemical comes into play when the muscle's store of ATP has been depleted, or used up. Creatine phosphate breaks down into creatine and phosphate, restoring the levels of ATP. The reason muscles ache after a difficult workout is that levels of ATP and creatine have fallen. As the body restores the chemical balance, the aches fade and the muscles become stronger.

Endogenous creatine is manufactured in the liver, kidneys, and pancreas. A normal, active human being manufactures about two grams of creatine daily, taking in perhaps one or two grams more through foods. Vegetarians tend to store less creatine in their bodies, since they do not eat meat.

Mark McGwire

In September of 1998, while working toward setting a new single-season home run record, St. Louis Cardinals slugger Mark McGwire talked with reporters at his locker in the stadium clubhouse. A photographer snapped a shot of McGwire's locker, showing a bottle of creatine supplements.

On March 17, 2005, McGwire was called to testify in Washington, D.C., before the House Committee on Governmental Reform. Facing tough questions from members of Congress, McGwire dodged the issue about whether he used performance-enhancing products. As reported in the Philadelphia Daily News, McGwire stated: "I cannot answer these questions without jeopardizing my friends, my family, and myself." McGwire wept when parents whose sons had died of complications of steroid abuse told the committee that their sons idolized McGwire and wanted to be like him.