What is Creatine used for?
Creatine is NOT a vitamin, mineral, herb, hormone, stimulant or steroid but is found naturally in the human body, and in most animals as well, where it is contained to nearly 95% in the muscles, and the rest in other body parts. Food sources that contain creatine include beef, pork, turkey, fish and chicken [1].
There is no documented therapeutic use for creatine, however there are a number of suggested uses for this agent. [1] The key to understanding creatine supplementation is to appreciate that it only helps with certain activities. A basic review of what creatine is, and how it is used in the body will help you understand how supplementation might be beneficial [2]. First, the basics. Muscle cells generate mechanical work from an energy liberating chemical reaction -- ATP is split into ADP and P (phosphate). Muscle cells can use ATP very quickly, but there is only an extremely limited supply -- usually only enough for a few seconds of high intensity work [3]. When the ATP is gone, work stops. Therefore one can see already that creatine may be used for exercises, requiring a short sudden burst of energy and may provide little benefit in endurance sports, needing continuos energy supply, over a period of time.
Who benefits from creatine supplements?
Since creatine supplementation increases muscular creatine levels, the next logical step would be to see if this helped athletic performance. From the brief discussion so far, one might expect that “power athletes” would benefit, and endurance athletes, not. Indeed, the exercise studies to date have confirmed that supposition [3]. Creatine supplementation is claimed to increase muscle power by playing a role in the transfer of energy to help the muscle contract. Supplement labels state that "creatine is converted to phosphocreatine, which is important for short energy bursts such as sprinting and weight lifting" and that "depletion of phosphocreatine can result in muscle fatigue and fading muscle power [4]." Claims are also made that supplementation increases muscle body mass. Creatine users seem to believe that creatine improves their performance, but they may lack sufficient information to make informed decisions regarding creatine use, therefore further large-scale studies are needed to investigate this further.
What studies have been done?
In double blind, placebo controlled studies, creatine supplementation showed impressive results in exercise results, as well as in weight training [5]. Less fatigue and a reduction of "burning" muscles were also experienced. Although studies involving rodents offer credence in the therapeutic use of Creatine, the results may not fully explain the usefulness in humans. Rodents typically have a higher blood Creatine level than humans, and do not respond to supplementation in the same manner that humans respond [5].
Other areas of research include therapeutic uses of creatine to help patients with muscle wasting problems caused by disease states such as muscular dystrophy, amyotrophic lateral sclerosis (ALS) and Huntington’s disease (HD) [2].
