| Creatine is a nitrogenous organic acid | | | | have absorption rates tens of times |
| that naturally occurs in vertebrates and | | | | higher than regular creatine |
| helps to supply energy to muscle cells. | | | | monohydrate, by several supplement |
| Creatine was identified in 1832 when | | | | companies. Once ingested, however, |
| Michel Eugene Chevreul discovered it as | | | | creatine is highly bioavailable (easily |
| a component of skeletal muscle which he | | | | measured by its plasma appearance |
| later named creatine after the Greek | | | | kinetics and urinary excretion), whether |
| word for flesh, Kreas. | | | | it is ingested as the crystalline |
| Function Creatine functions as part of | | | | monohydrate form, the free form in |
| the cell's energy shuttle. The high | | | | solution, or even in meat. |
| energy phosphate group of ATP is | | | | Creatine salts will of course become the |
| transferred to creatine to form | | | | free form when dissolved in aqueous |
| phosphocreatine in the following | | | | solution. With studies repeatedly |
| reaction: Cr + ATP PCr + ADP. This | | | | reporting an upper maximal range for |
| reaction is reversibly catalysed by | | | | muscular creatine concentration it is |
| creatine kinase, also referred to as | | | | unlikely that the form of creatine |
| creatine phosphokinase. At sites of high | | | | ingested results in increased or altered |
| energy usage, e.g. at the site of muscle | | | | final gains. Creatine monohydrate ($400 |
| contraction or in the tail of a sperm | | | | million in annual sales in the United |
| cell, creatine kinase transfers the high | | | | States alone) remains the most used form |
| energy phosphate back from | | | | of creatine. |
| phosphocreatine to ADP to reform ATP. | | | | Creatine Ethyl Ester (CEE) is not |
| This allows the cellular ATP/ADP ratio | | | | allowed to be sold in Germany and |
| to remain stable within the cell, even | | | | France. |
| if it is undergoing rapid energy | | | | Creatine and Athletic Performance |
| fluctuations. Creatine kinase is | | | | Creatine is often taken by humans as a |
| typically located in cells that undergo | | | | supplement for those wishing to gain |
| high energy fluctuations, e.g. muscle | | | | muscle mass (bodybuilding). There are a |
| cells, cardiac muscle cells, neurons, | | | | number of forms but the most common are |
| the photoreceptor cells of the eye and | | | | creatine monohydrate - creatine bonded |
| spermatozoa. An analogous system based | | | | with a molecule of water, and creatine |
| on arginine/phosphoarginine operates in | | | | ethyl ester (CEE) – which is creatine |
| many invertebrates. The presence of this | | | | monohydrate with an ester attached. A |
| energy shuttle keeps the ATP/ADP ratio | | | | number of methods for ingestion exist - |
| high, which ensures that the free energy | | | | as a powder mixed into a drink, or as a |
| of ATP remains high and minimizes the | | | | pill. |
| loss of adenosine nucleotides, which | | | | There is scientific evidence that taking |
| would cause cellular dysfunction. | | | | creatine supplements can marginally |
| Synthesis In the human body creatine is | | | | increase athletic performance in |
| synthesized mainly in the liver by the | | | | high-intensity anaerobic repetitive |
| use of parts from three different amino | | | | cycling sprints, but studies in swimmers |
| acids - arginine, glycine, and | | | | and runners have been less than |
| methionine. 95% of it is later stored in | | | | promising, possibly due to the weight |
| the skeletal muscles, with the rest in | | | | gain. Ingesting creatine can increase |
| the brain, heart, testes. | | | | the level of phosphocreatine in the |
| Creatine and the treatment of muscular | | | | muscles up to 20%. It must be noted |
| diseases Creatine supplementation has | | | | creatine has no significant effect on |
| been, and continues to be, investigated | | | | aerobic exercise (Engelhardt et al, |
| as a possible therapeutic approach for | | | | 1998). |
| the treatment of muscular, neurological | | | | Some studies have shown that creatine |
| and neuromuscular diseases (arthritis, | | | | supplementation increases both total and |
| congestive heart failure, disuse | | | | fat-free body mass, though it is |
| atrophy, gyrate atrophy, McArdle's | | | | difficult to say how much of this is due |
| disease, Huntington's disease, | | | | to the training effect. Since body mass |
| miscellaneous neuromuscular diseases, | | | | gains of about 1 kg (about 2.2 pounds) |
| mitochondrial diseases, muscular | | | | can occur in a week's time, several |
| dystrophy, neuroprotection, etc.). | | | | studies suggest that the gain is simply |
| Two scientific studies have indicated | | | | due to greater water retention inside |
| that creatine may be beneficial for | | | | the muscle cells. However, studies into |
| neuromuscular disorders. First, a study | | | | the long-term effect of creatine |
| (Klivenyi et al. 1999) by MDA-funded | | | | supplementation suggest that body mass |
| researcher M. Flint Beal of Cornell | | | | gains cannot be explained by increases |
| University Medical Center demonstrated | | | | in intracellular water alone. In the |
| that creatine was twice as effective as | | | | longer term, the increase in total body |
| the prescription drug riluzole in | | | | water is reported to be proportional to |
| extending the lives of mice with the | | | | the weight gains, which means that the |
| degenerative neural disease amyotrophic | | | | percentage of total body water is not |
| lateral sclerosis (ALS, or Lou Gehrig's | | | | significantly changed. The magnitude of |
| disease). Beal suspects that the | | | | the weight gains during training over a |
| neuroprotective effects of creatine in | | | | period of several weeks argue against |
| the mouse model of ALS are due either to | | | | the water-retention theory. |
| an increased availability of energy to | | | | It is possible that the initial increase |
| injured nerve cells or to a blocking of | | | | in intracellular water increases osmotic |
| the chemical pathway that leads to cell | | | | pressure, which in turn stimulates |
| death. | | | | protein synthesis. A few studies have |
| Second, a study by Canadian researchers | | | | reported changes in the nitrogen balance |
| Mark Tarnopolsky and Joan Martin of | | | | during creatine supplementation, |
| McMaster University Medical Center in | | | | suggesting that creatine increases |
| Hamilton, Ontario found that creatine | | | | protein synthesis and/or decreases |
| can cause modest increases in strength | | | | protein breakdown. Again, while |
| in people with a variety of | | | | hypothesized, this remains unproven. |
| neuromuscular disorders. The latter | | | | Also, research has shown that creatine |
| paper was published in the March 1999 | | | | increases the activity of myogenic |
| issue of Neurology. | | | | cells. |
| History of use as a nutritional | | | | These cells, sometimes called satellite |
| supplement In 1912, researchers found | | | | cells, are myogenic stem cells that make |
| that ingesting creatine can dramatically | | | | hypertrophy (increase in size of cells) |
| boost the creatine content of the | | | | of adult skeletal muscle possible. These |
| muscle. In the late 1920s, after finding | | | | stem cells are simply generic or |
| that the intramuscular stores of | | | | non-specific cells that have the ability |
| creatine can be increased by ingesting | | | | to form new muscle cells following |
| creatine in larger than normal amounts, | | | | damage to the muscle tissue, or to fuse |
| scientists discovered creatine | | | | with the existing muscle fibres in the |
| phosphate, and determined that creatine | | | | case of exercise to permit growth of the |
| is a key player in the metabolism of | | | | muscle fibre. Following proliferation |
| skeletal muscle. | | | | (reproduction) and subsequent |
| While creatine's influence on physical | | | | differentiation (to become a specific |
| performance has been well documented | | | | type of cell), these satellite cells |
| since the early twentieth century, it | | | | will fuse with one another or with the |
| only recently came into public view | | | | adjacent damaged muscle fiber, thereby |
| following the 1992 Olympics in | | | | increasing myonuclei numbers necessary |
| Barcelona. | | | | for fiber growth and repair. The study, |
| An August 7, 1992 article in The Times | | | | published in the International Journal |
| reported that Linford Christie, the gold | | | | of Sports Medicine was able to show that |
| medal winner at 100 meters, had utilized | | | | creatine supplementation increased the |
| creatine prior to the Olympics, and an | | | | number of myonuclei donated from |
| article in Bodybuilding Monthly named | | | | satellite cells. This increases the |
| Sally Gunnell, gold medalist in the | | | | potential for growth of those fibers. |
| 400-meter hurdles, as another creatine | | | | This increase in myonuclei probably |
| user. Several medal-winning British | | | | stems from creatine's ability to |
| rowers also used creatine during their | | | | increase levels of the myogenic |
| preparations for the Barcelona games. | | | | transcription factor MRF4 (Hespel, |
| At the time, low-potency creatine | | | | 2001). |
| supplements were available in Britain, | | | | Current studies indicate that short-term |
| but creatine supplements designed for | | | | creatine supplementation in healthy |
| strength enhancement were not | | | | individuals is safe (Robinson et al., |
| commercially available until 1993 when a | | | | 2000). Longer term studies have |
| company called Experimental and Applied | | | | occasionally been done, but have been |
| Sciences (EAS) introduced the compound | | | | small. One such study that is often |
| to the sports nutrition market under the | | | | cited involved a minimum length of 3 |
| name Phosphagen. In 1998, the launch of | | | | months, but only had 10 creatine |
| the first creatine-carbohydrate-alpha | | | | subjects (Mayhew et al 2002). However, |
| lipoic acid supplement, Cell-Tech, by | | | | there is still controversy over the use |
| another company called MuscleTech | | | | of creatine, and many experts believe |
| Research and Development, took place. | | | | that creatine should not be used by |
| Alpha lipoic acid enhances muscle | | | | individuals under the age of 18. |
| phosphocreatine levels and total muscle | | | | [citation needed]Therefore more research |
| creatine concentrations. This approach | | | | is needed to be done on this supplement |
| to creatine supplementation was | | | | and others like it before being used. |
| validated in a study performed in 2003 | | | | There has been controversy over the |
| by Burke et al., of the Department of | | | | incidence of muscle cramping with the |
| Human Kinetics at St. Francis Xavier | | | | use of creatine. A study done at the |
| University. Another important event in | | | | University of Memphis showed no reports |
| creatine supplementation occurred in | | | | of muscle cramping in subjects taking |
| 2004 when the first creatine ethyl ester | | | | creatine-containing supplements during |
| supplements were launched. | | | | various exercise training conditions in |
| Creatine Ethyl Ester (CEE) is becoming a | | | | trained and untrained endurance athletes |
| widely used form of creatine, with many | | | | (Kreider R. et al, 1998). |
| companies now carrying both creatine | | | | Creatine use is not considered doping |
| monohydrate-based supplements and | | | | and is not banned by sport-governing |
| Creatine Ethyl Ester supplements, or | | | | bodies. In some countries however, |
| combinations of both. CEE is touted to | | | | creatine is banned. |