Creatine

Chemical structure

Ball and stick structure

Creatine is a combination of three non-essential amino acids. These are methionine, arginine and glycine. Creatine is used to produce adenosine triphosphate. The short word for Adenosine triphosphate is ATP. ATP is the energy of the human body. Creatine is already in the body as a natural substance and in some food (for example beef). The body changes creatine to phosphocreatine. It is then stored as energy in the muscles. The energy systems of the body are: aerobic, lactate and phosphocreatine. Most of the creatine is used in the lactate system and the phosphocreatine system because these two systems need more energy the aerobic system. They also take a part of the energy from the production or the absorption of creatine.

Effects on the human body

Creatine has two main effects: increase of muscles and increase the amount of protein synthesis. The increase comes from the water retention of cells that store creatine. For protein synthesis, it is not entirely known, but creatine can help with the recovery of muscle. During the time a body recovers from training, the creatine gives extra energy so the cells of the muscle can speed up the protein absorption of the cells.

The creatine is used by all the human body because it travels by the blood stream. The heart and the muscles are the main parts that use creatine cells. Most of the creatine production will be stored in the skeletal muscle because these muscles need a lot of energy and they need it quickly. The body produces about two grams of creatine per day. Only 90 to 95 percent of the human creatine production will travel in the blood stream. The five to ten percent that is not used is lost.

Creatine Media

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  クレアチンの合成経路

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  Proposed creatine kinase/phosphocreatine (CK/PCr) energy shuttle. CRT = creatine transporter; ANT = adenine nucleotide translocator; ATP = adenine triphosphate; ADP = adenine diphosphate; OP = oxidative phosphorylation; mtCK = mitochondrial creatine kinase; G = glycolysis; CK-g = creatine kinase associated with glycolytic enzymes; CK-c = cytosolic creatine kinase; CK-a = creatine kinase associated with subcellular sites of ATP utilization; 1 – 4 sites of CK/ATP interaction.

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  Approximate muscle total creatine levels in mmol/kg dry weight muscle reported in the literature for vegetarians, individuals following a normal diet, and in response to creatine loading with or without carbohydrate (CHO) or CHO and protein (PRO). Dietary supplementation of creatine serves to increase muscle creatine and PCr by 20–40%

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  This graph shows the mean plasma creatine concentration over an 8 hour period following ingestion of 4.4 grams of creatine in the form of creatine monohydrate (CrM), tri-creatine citrate (CrC), or creatine pyruvate (CrPyr).