A non-essential protein-like compound found in muscle and the brain. It is synthesized in the liver from the two amino acids arginine and glycine, and then taken up from the bloodstream into the muscle where it becomes phosphocreatine. During exercise, phosphocreatine donates its high-energy phosphate molecule to create adenosine triphosphate (ATP), which is used by the muscle for contraction.
Creatine is most commonly used for improving exercise performance and increasing muscle mass in athletes and older adults. There are numerous scientific studies supporting the use of creatine for improving the athletic performance of young, healthy people during brief high-intensity activity such as sprinting and weightlifting. Because of this, creatine is often used as a dietary supplement to improve muscle strength and overall athletic performance.
Creatine will naturally pull water into the muscle, giving it a fuller, rounder look. However, the bowel is a muscle, and creatine can pull water into the bowel causing a temporary osmotic diarrhea, especially when supplementing with too high a dose. The average recommendation is three to five grams of creatine per day. There is little evidence that taking higher doses, or taking a “loading dose” of 10 grams or higher, provides any benefit.