Creatine is a supplement that first became available to bodybuilders in 1993.  It has become the best selling supplement ever with the possible exception of protein powder, which has been around longer and continues to improve as well.  Let me make the point that the supplement in question here is creatine monohydrate and not citrate nor phosphate.  There, as of rewriting this article, have been no studies on humans showing the benefits of any other form of creatine.  In other words, anyone that has gotten a letter about that Turbo Blast 600 liquid creatine crap from SoCal should tell them to produce a study that shows what they are talking about.  The one form of creatine that you should be interested in should be creatine monohydrate until this is proven otherwise and there are many studies that confirm the effectiveness of creatine.  If you don't believe me, then do a search on Medline in my links page for the several hundred abstracts on creatine that are freely available.

Creatine monohydrate is a naturally occurring energy substrate found in red muscle tissue. This substance is composed of three different amino acids that are found in the body. There are several theories as to how creatine monohydrate works in promoting muscle strength and size. One is the "cell volumizing" action. Muscle cells regulate the amount of fluid that they contain. When creatine enters a muscle cell, the cells try to dilute the amount of the compound by letting water into the muscle cells to try to dilute it. So, in effect, creatine tricks your muscles into taking in water to counter the creatine that they are taking in which causes them to fill out and look larger. This increase of water inside muscle cells can exert powerful effects upon muscle anabolism and catabolism. This will in turn cause an increase in muscle, whole body nitrogen retention, and net protein synthesis. The volumizing effect that you get causes increased amino acid transport into the cell while at the same time inhibiting protein breakdown.  Secondly, it will give you more energy by regenerating ATP in to anaerobic energy pathway. This is especially good for endurance athletes such as cyclists or runners.