How Does Creatine Work?

Creatine at the Physical Level

Creatine is a naturally synthesized protein found in the human body, it is synthesized from three different amino acids; methionine, glycine and arginine. It is found in the brain, heart and 95 percent of the body's creatine is found in skeletal muscle. Creatine's most important role is in the body's energy system, where creatine transports the phosphate required in the conversion of ADP to ATP. ATP is the body's energy storage molecule, when a muscle works it gets its energy from ATP which when converted to ADP gives up it energy. Muscles have only a limited supply of ATP and once they are used up, the body had to fnd ways to convert the ADP back to ATP. The quickest way is take the phosphate from phosphocreatine. Creatine is also created synthetically and marketed as a performance supplement. This supplement is mainly ingested to improve athletic performance and also to increase lean body mass. Creatine has however proven to be beneficial to athletes who use fast twitch muscles, like sprinters. This is because fast twitch muscle succumb to oxygen debt and the creatine at the physiological level fills in the gaps required for fast recovery and modified energy generation. The slow twitch muscles of a long distance runner do not benefit from additional use of creatine since the body functions with a "pay as you go" system with the energy consumption.

Creatine at the Cellular Level

Once ingested creatine enters the blood stream, there are several different proposed mechanisms on how creatine exerts its athletic enhancing and muscle building effects.

There is an increase in the intramuscular levels of creatine. This helps maintain a high ATP/ADP ratio, where ATP is the body's energy store. Creatine phosphate is said to give the phosphate required to convert ADP to ATP.

Creatine inadvertently buffers the protons from accumulating in the acidic environment caused by anaerobic exercises. Creatine does this by bypassing glycolysis, the mechanism the body normally uses to make energy. By bypassing glycolysis, the body no longer makes lactic acid in anaerobic situations, which means the burning sensation one feels after strenuous exercise is prevented.

Helps in the energy transfer from the mitochondria to body sites where ATP is used in a process called the creatine phosphate shuttle. The shuttle is based on the supposition that the energy rich phosphate bond is transported to the muscles via creatine phosphate.

Converts back to amino acids which are used to synthesize muscles tissues. This may lead to your increased strength and lean body mass.

Warnings

Do not take Creatine Supplements if you are pregnant.
Creatine use may lead to muscle strain, tearing or breakdown.
If you are diabetic, creatine can interfere with your insulin absorption. Check with your healthcare provider before using creatine supplements.
Creatine may cause gastrointestinal complications like loss of appetite, diarrhea and nausea.
Ingestion of large quantities of creatine can lead to the production of formaldehyde which also has undesired effects.

Resources

• Mayo Clinic- about Creatine
• Creatine Supplement use in Athletes