Creatine is composed of three amino acids; arginine, glycine and methionine and is technically known as methylguanido. Creatine exists naturally in many common foods including beef and fish. Also, it is made everyday by our liver, pancreas and kidneys. On average, a healthy male makes 2 grams of Creatine daily and depletes about the same amount during normal activities. For non-athletes, as you can see, Creatine maintains a fairly good balance without the need for supplementation. In order to understand how this changes for a gym trained athlete, we need to look more closely at the muscles.
The human body contains more than 400 separate muscles totaling over one quarter of a billion distinct muscle cells. A normal male can store about 120 grams of Creatine in the body, almost all of it existing in the various muscles. Although individual muscle size varies dramatically from person to person, muscle growth is highly related to the amount of use the muscle receives. In general, the more a muscle is worked, the more it grows. During this growth process protein is broken down and re-synthesized and muscle growth occurs.
More specifically, muscle growth results from four separate factors. First, there needs to be a stimulus that causes a contraction of the muscle at near maximal force. Second, there needs to be an adequate supply of energy to power the muscle contraction. Third, there must be adequate nutrients such as minerals and amino acids present to be used in the muscle building process. Finally, there needs to be an adequate supply of “biochemical materials” present such as hormones, growth factors or their intermediates.
The main purpose behind Creatine supplementation is to provide the energy to allow a muscle to contract more intensely, for longer durations and more frequently.
During weightlifting, the muscles require tremendous amounts of immediate energy. This energy is made available primarily from Adenosine Triphosphate (ATP). Although the need for ATP may increase one thousand fold during intense exercise, ATP can only be stored in the muscles in extremely small quantities. For maximal muscle work to occur, then, ATP needs to be replentished constantly during muscle work. Creatine acts as the primary resupplier of of ATP levels for high intensity muscle building exercises. During muscle contractions, ATP is hydrolysed to Adenosine Diphosphate (ADP). Creatine regenerates ATP levels by breaking down and lending the phosphate.
Creatine is not a new substance. The first scientific study on Creatine was published in 1926 in the Journal of Biological Chemistry. The results of this study showed that Creatine promoted weight gain and nitrogen balance. Oddly, over the following decades, researchers showed minimal interest in Creatine although there were a few studies that found results comprable to the original research. It wasn’t until 1993 when the Scandinavian Journal of Medicine, Science and Sports published a study demonstrating that Creatine supplementation significantly increased body mass in one week. Furthermore, the study found that Creatine improved performance in high intensity, intermittent exercise.
Following this landmark report, there have been dozens of published, double blind clinical studies proving that Creatine supplementation improves anaerobic muscle performance, adds strength, facilitates recovery and increases sprint speed.
Currently, researchers are focusing on studying some of the less dramatic, yet very positive, effects Creatine may have on athletes. First, Creatine is being studied as a compound which can help decrease body fat. There are preliminary results demonstrating that athletes on Creatine not only gain lean mass but also lose bodyfat. Technically, as lean mass is added, the body should become more efficient at burning calories. The net result would be a lowering of bodyfat. It appears from the rate of fat loss, however, that Creatine is facilitating fat loss through additional biochemical mechanisms. Research is continuing into the exact manner in which fat loss is occuring.
Creatine also acts as a powerful muscle volumizer. When Creatine is drawn into the muscle cell, it brings water in wioth it. The water pumps up the muscle and makes it feel and appear larger. Volumization may also trigger protein and glycogen synthesis. This makes bigger, strong individual muscle fibers.
Finally, Creatine may act as a lactic acid buffer and help to increase endurance.