Derived from the Greek word for flesh, it is a compound that is naturally produced in humans and other vertebrates. It was first discovered in 1832 by Michel Chevreul. It gained it’s popularity during the 1990s, because of the Olympic Games, in which two of the gold-medallists have used it to attain their results. Creatine is stored in muscle tissue and is found in high amounts in various types of meat such as beef, chicken and tuna (“high amounts” meaning that there are at least 2 grams of it per kg of flesh).
The most common variation of creatine is monohydrate. This is the only type that can be found naturally, and the type on which most of the studies have been performed on. If someone is talking about creatine, this is usually the one they mean. Some of the other types of creatine include: hydrochloride, pyruvate, ethyl ester, magnesium chelate, malate, citrate, alphaketoglutarate etc. None of these have been proved to work better than the classic, but there are many anecdotes to speak on their behalf instead. The variations are allegedly used to avoid the unpleasant, yet very much harmless, side-effects of creatine monohydrate.
Creatine works by improving the regeneration of ATP (adenosine triphosphate) in the muscles. ATP is the chemical that provides energy for the contraction of muscles, among many other things. An enzyme called creatine kinase is used to commence the process. This enzyme binds creatine with a phosphorus atom from ATP in the cells, creating ADP (adenosine diphosphate) and PCr (phosphocreatine). The PCr migrates to the muscle fibers where it assists in generating ATP in the following way: As ATP is it used for energy, ADP, a hydron atom and a single phosphorus atom are left as byproducts of this chemical reaction. This reaction is reversible, meaning that it goes both ways. This in turn means that ATP can be created by ADP + H+ + P. In the case with creatine, PCr takes the place of the phosphate atom. Creatine becomes then a byproduct of this reaction, being able to restart the process and provide even more energy to the muscle fibers.
There are two ways to start using creatine: with a loading phase or without. A loading phase means that the user ingests a greater than regular dosage of creatine for a predetermined amount of days, usually a week, and then resuming to supplement with a much lower dosage, often being 5 times less in amount. There are studies that have looked into this and have found no benefits for the athlete engaged in long-term supplementation. This means that if the user intends to supplement for more than a week or two, no loading phase is necessary nor required. While the minimum effective dosage is about two grams per day, or about 0.03g/kg, many resolve upon ingesting 5 grams instead, due to the low price of this product.
Being one of, if not the most studied supplement, various different benefits have been found from supplementation with creatine. The most sought out effect of creatine is the increased power output, as previously alluded to in the “How does it work?”-section. A relatively recent study by Rawson and Volek, published in 2003, has shown an average increase in power output by 26%, compared to the placebo group, which has experienced an increase of only 12%.
Some studies have also shown increases in lean mass, but the amount has been difficult to estimate due to the increase of weight in general, which will be addressed later in this article.
Creatine alongside exercise has been proven to decrease circulating myostatin by 17%. Myostatin is a protein that inhibits muscle cell growth, meaning that supplementation would be beneficial. This correlates with the previously mentioned hypothesized lean mass gain.
While one study has found a increase in DHT (dihydrotestosterone) and no significant increase in testosterone, and an other one has found an increase in testosterone by 15%.
A study has also shown a decrease in mental fatigue after supplementing with 8 grams of creatine for 5 days. The subjects were tested by performing mathematical calculations.
It is of great importance to mention that studies do not reflect the reality in many cases, both due to the room for error and to the subject groups not reflecting every individual.
There are no significant confirmed side effects besides diarrhea and cramping. The former is caused by an acute high dosage ingestion, and the latter by insufficient hydration. Weight gain could also be counted as a side effect, due to creatine increasing both dry matter amount and water retention. A hypothesized adverse effect that has not been proven due to a great lack of evidence is hair loss. As previously mentioned, creatine supplementation increases DHT. This metabolite of testosterone is able to bind to receptors on the hair follicles thus causing them to shrink and discontinue hair production. Because the increase in DHT was large, but still in normal range, we can conclude that hair loss in genetically predisposed men would not occur significantly faster than naturally. While not significant, it is worth mentioning that creatine supplementation leads to an increase in creatinine levels, because of the fact that not all creatine that is ingested gets metabolized. Creatinine levels are often used as a marker for assessment of renal function. A higher value usually indicates kidney dysfunction. In the case of a creatine-supplementing athlete, this would result in a false positive.
Although it is found in many types of meat, creatine is simply impractical to consume in large amounts on a daily basis. It would require a consumption of at least 1 kg of meat per day, which could be detrimental to health in multiple ways. An ingestion of 5 grams of creatine monohydrate daily is suggested, without a loading phase. There are many benefits of creatine supplementation, with no noteworthy drawbacks. The unwanted side effects can be mitigated or prevented by increasing hydration and spreading the creatine intake throughout the day.