What is it? Overview Usage Side Effects and Warnings

What is Creatine?

Creatine is a naturally occurring substance that plays an important role in the production of energy in the body. The body converts it to phosphocreatine, a form of stored energy used by muscles.

Although the evidence for creatine is not definitive, it has the most evidence behind it among all the sports supplements. Numerous small double-blind studies suggest that it can increase athletic performance in sports that involve intense but short bursts of activity.

The theory behind its use is that supplemental creatine can build up a reserve of phosphocreatine in the muscles to help them perform on demand. Supplemental creatine may also help the body make new phosphocreatine faster when it has been used up by intense activity.

Creatine is one of the best-selling and best documented supplements for enhancing athletic performance , but the scientific evidence that it works is far from complete. The best evidence we have points to potential benefits in forms of exercise that require repeated short-term bursts of high-intensity exercise; this has been seen more in artificial laboratory studies, though, rather than in studies involving athletes carrying out normal sports. 1 It might also be helpful for resistance exercise (weight training), although not all studies have found benefit. 2 Creatine has also been proposed as an aid to promote weight loss and to reduce the proportion of fat to muscle in the body, but there is little evidence that it is effective for this purpose. 3 Preliminary evidence...

Safety Issues

Creatine appears to be relatively safe. 4 No significant side effects have been found with the regimen of several days of a high dosage (15 g to 30 g daily) followed by 6 weeks of a lower dosage (2 g to 3 g daily). A study of 100 football players found no adverse consequences during 10 months to 5 years of creatine supplementation. 5 Contrary to early reports, creatine does notappear to adversely affect the body's ability to exercise under hot conditions and might even be beneficial. 6 Dividing the dose may help avoid gastrointestinal side effects (diarrhea, stomach upset, and belching). In one study of 59 male soccer players, two separate 5 g doses was associated with less diarrhea than a single 10 g dose. 7 However, there are some potential concerns...