General Description
Creatine is a nitrogen-containing organic acid that is synthesized
by the body and stored primarily in muscle tissues in the form of
phosphocreatine (also known as creatine phosphate). Phosphocreatine
aids in energy production by donating phosphate to ADP to make ATP,
the principal source of energy for muscle tissues. In addition to
that which is manufactured within the body, small amounts of creatine
may be obtained through the diet, primarily in foods high in animal
protein such as meat and fish. Creatine is also available as a dietary
supplement in the form of creatine monohydrate.
Health Applications
- Increased muscle mass/strength
- Athletic performance
Primary Uses
Creatine supplements are used primarily by athletes, weight lifters,
and body builders who wish to increase muscle strength and lean
muscle mass. Many small-scale studies indicate that creatine supplementation
can increase lean body mass and muscular strength and improve
performance in high-intensity, short-duration exercises.1-18
However, other studies failed to show performance enhancement
in well-trained athletes,19-25 and creatine
does not appear to improve endurance performance or aerobic exercise
capacity. Due to small test-group size and inconsistent results,
larger studies are needed before the effects of supplemental creatine
can be determined.
Dosage/Toxicity
Studies with positive results have generally used 20 grams of
creatine monohydrate per day for at least 5 days.14-18
Smaller doses or shorter periods of administration may not be
sufficient to significantly raise muscle phosphocreatine levels.26
Creatine has very low toxicity and appears to be well tolerated
at this dosage range; however, the long-term effects of creatine
supplementation are unknown at this time. |
