Creatine is a non-protein amino acid derivative found in human tissue that is synthesized from the amino acids L-arginine, glycine, and L-methionine. Synthesized creatine is metabolized into phosphocreatine, an important storage form used by the brain, heart, and skeletal muscles.40 In normal healthy individuals, muscle creatine is replenished at a rate of approximately two grams a day.41 Oral ingestion of creatine has been shown to suppress the body’s natural production, an effect that has been shown to be reversed upon ceasing supplementation.41

Creatine exerts various effects upon entering the muscle. It is these effects that elicit improvements in exercise performance and may be responsible for the improvements of muscle function and energy metabolism seen under certain conditions. Several mechanisms have been proposed to explain the increased exercise performance seen after creatine intake.42

1. Optimizing energy metabolism by maintaining higher levels of the body’s energy compound adenosine triphosphate or ATP43-45
2. Increasing myofibrillar mRNA content and protein synthesis, and reducing amino acid oxidation and protein breakdown42,46,47
3. Increasing satellite cell and myonuclei number and activity in human skeletal muscle48
4. Preventing tissue damage by stabilizing cellular membranes and maintaining reserves of ATP42

Creatine monohydrate has become popular with athletes, but it may also be beneficial for people who are nutritionally deficient, have conditions associated with low cellular energy, muscle weakness, and those concerned with the muscular integrity of the heart.49-57