Edit filter log

'{{Dablink|For the biochemistry and physiology of creatine, see [[Creatine]].}} '''Creatine supplements''' are athletic aids used to increase high-intensity athletic performance. Though researchers have known of the use of [[creatine]] as an energy source by [[skeletal muscle]]s since the beginning of the 20th century, they were popularized as a performance-enhancing supplement in 1992. ==History of creatine supplements== In 1912, [[Harvard University]] researchers [[Otto Folin]] and [[Willey Glover Denis]] found proof that ingesting [[creatine]] can dramatically boost the creatine content of the muscle.<ref>{{cite journal |author=Folin O, Denis W |title=Protein metabolism from the standpoint of blood and tissue analysis. Third paper, Further absorption experiments with especial reference to the behavior of creatine and creatinine and to the formation of urea.| journal=Journal of Biological Chemistry |volume=12 |issue= 1 |year=1912 |pages=141–61 }}</ref> In the late 1920s, after finding that the intramuscular stores of creatine can be increased by ingesting creatine in larger than normal amounts, scientists discovered ''[[Phosphocreatine|creatine phosphate]]'', and determined that creatine is a key player in the metabolism of [[skeletal muscle]]. The substance creatine is naturally formed in vertebrates. While creatine's influence on physical performance has been well documented since the early twentieth century, it came into public view following the [[1992 Summer Olympics|1992 Olympics]] in [[Barcelona]]. An August 7, 1992 article in ''[[The London Times]]'' reported that [[Linford Christie]], the gold medal winner at 100 meters, had used creatine before the Olympics. An article in ''[[Bodybuilding Monthly]]'' named [[Sally Gunnell]], who was the gold medalist in the 400-meter hurdles, as another creatine user. In addition, ''The Times'' also noted that 100 meter hurdler [[Colin Jackson]] began taking creatine before the Olympics.<ref>{{cite web|url=http://www.nationalreviewofmedicine.com/issue/2004_07_30/feature07_14.html|title=Supplement muscles in on the market |publisher=National Review of Medicine |date=204-07-30 |accessdate=2011-05-25}}</ref><ref>{{cite book |title=Creatine |last=Passwater |first=Richard A. |coauthors= |year=2005 |publisher= |location= |isbn=0-87983-868-x |page=9 |url=http://books.google.ca/books?id=umy67wOLOckC&printsec=frontcover#v=onepage&q&f=false |accessdate=2011-05-25}}</ref> At the time, low-potency creatine supplements were available in Britain, but creatine supplements designed for strength enhancement were not commercially available until 1993 when a company called [[Experimental and Applied Sciences]] (EAS) introduced the compound to the sports nutrition market under the name ''Phosphagen''.<ref>{{Cite book |last= Stoppani |first= Jim |title= Creatine new and improved: recent high-tech advances have made creatine even more powerful. Here's how you can take full advantage of this super supplement |publisher= [[Muscle & Fitness]] |date= May, 2004 |url= http://findarticles.com/p/articles/mi_m0801/is_5_65/ai_n6005938 |accessdate= 2010-03-29}}</ref> Research conducted afterward showed that the consumption of high [[Glycemic index|glycemic]] carbohydrates in conjunction with creatine increases creatine muscle stores and performance.<ref>{{cite journal |author=Green AL, Hultman E, Macdonald IA, Sewell DA, Greenhaff PL |title=Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans |journal=Am. J. Physiol. |volume=271 |issue=5 Pt 1 |pages=E821–6 |year=1996 |month= November|pmid=8944667 |url= http://ajpendo.physiology.org/cgi/pmidlookup?view=reprint&pmid=8944667}}</ref> In 1998, [[MuscleTech|MuscleTech Research and Development]] launched Cell-Tech, the first creatine-carbohydrate-alpha lipoic acid supplement.<ref>[http://books.google.ca/books?id=qrCNDfbkQ-cC&pg=PA3&lpg=PA3&dq=cell-tech+first+creatine+alpha+lipoic+1998&source=bl&ots=eM5OhOtP-R&sig=Ay2ygiemWCCxG_lE96zwcfZ7lxw&hl=en&ei=WtRzTMeKCIGGnQe90am7CQ&sa=X&oi=book_result&ct=result&resnum=10&ved=0CDkQ6AEwCQ#v=onepage&q=cell-tech%20first%20creatine%20alpha%20lipoic%201998&f=false Profiles of Drug Substances, Excipients and Related Methodology By Harry G. Brittain]</ref> [[Alpha lipoic acid]] has been demonstrated to enhance muscle phosphocreatine levels and total muscle creatine concentrations. This approach to creatine supplementation was supported by a study performed in 2003.<ref>{{cite journal |title=Effect of alpha-lipoic acid combined with creatine monohydrate on human skeletal muscle creatine and phosphagen concentration |journal=International Journal of Sport Nutrition and Exercise Metabolism |volume=13 |issue=3 |pages=294–302 |publisher=Human Kinetics Publishers |date=2003-09-01 |pmid=14669930 |author=Burke DG, Chilibeck PD, Parise G, Tarnopolsky MA, Candow DG }}</ref> == Creatine and athletic performance == Creatine is often taken by athletes to help as a [[bodybuilding supplements|supplement]] for those wishing to gain muscle mass ([[bodybuilding]]). There are a number of forms but the most common are creatine monohydrate (creatine complexed with a molecule of [[water]]) and [[creatine ethyl ester]] (CEE). A number of methods for ingestion exist: as a powder mixed into a drink, or as a capsule or caplet. Once ingested, creatine is highly [[Bioavailability|bioavailable]], whether it is ingested as the crystalline monohydrate form, the free form in solution, or even in meat. Creatine salts will become the free form when dissolved in aqueous solution. Conventional wisdom recommends the consumption of creatine with high [[glycemic index]] [[carbohydrate]]s.<ref>{{cite journal |author=Steenge GR, Simpson EJ, Greenhaff PL |title=Protein- and carbohydrate-induced augmentation of whole body creatine retention in humans |journal=J. Appl. Physiol. |volume=89 |issue=3 |pages=1165–71 |date=1 September 2000|pmid=10956365 |url=http://jap.physiology.org/cgi/content/full/89/3/1165 }}</ref> There is scientific evidence that short term creatine use can increase maximum power and performance in high-intensity anaerobic repetitive work (periods of work and rest) by 5 to 15%. This is mainly bouts of running/cycling sprints and multiple sets of low [[Strength Training#Terminology|RM]] weightlifting. Single effort work shows an increase of 1 to 5%. This refers mainly to single sprints and single lifting of 1-2RM weights. However, some studies show no ergogenic effect at all.<ref name="Kreider R, Rasmussen C, Ransom J, Almada AL. 1998">{{cite journal | author=Kreider R, Rasmussen C, Ransom J, Almada AL. | title=Effects of creatine supplementation during training on the incidence of muscle cramping, injuries and GI distress.| journal=Journal of Strength Conditioning Research | volume=12 | issue= 275 | year=1998 }}</ref> Studies in endurance athletes have been less than promising, most likely because these activities are sustained at a given intensity and thus do not allow for significant intra-exercise synthesis of additional creatine phosphate molecules. Ingesting creatine can increase the level of [[phosphocreatine]] in the muscles up to 20%. It must be noted creatine has no significant effect on aerobic [[Endurance#Endurance exercise|endurance]], though it will increase power during short sessions of high-intensity aerobic exercise.<ref>{{cite journal |last=Engelhardt |first=M |coauthors=Neumann G, Berbalk A, Reuter I |title=Creatine supplementation in endurance sports |journal=Medicine & Science in Sports & Exercise |volume=30 |issue=7 |pages=1123–9 |date=1998-07-01 |publisher=Lippincott Williams & Wilkins |pmid=9662683 |doi=10.1097/00005768-199807000-00016}}</ref><ref name=Graham>{{cite journal |author=Graham AS, Hatton RC |title=Creatine: a review of efficacy and safety |journal=J Am Pharm Assoc (Wash) |volume=39 |issue=6 |pages=803–10; quiz 875–7 |year=1999 |pmid=10609446 }}</ref> Since body mass gains of about 1 [[Kilogram|kg]] can occur in a week's time, many studies suggest that the gain is simply due to greater water retention inside the muscle cells.<ref>{{cite journal |last=Powers |first=M |coauthors=Arnold B et al. |title=Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution |journal=Journal of Athletic Training |volume=38 |issue=Jan-Mar |pages=44–50 |publisher=National Athletic Trainers' Association, Inc|year=2003 |pmc=155510 |pmid =12937471}}</ref> Other studies, however, have shown that creatine increases the activity of [[satellite cells]], which make [[muscle hypertrophy]] possible. Creatine supplementation appears to increase the number of myonuclei that satellite cells will 'donate' to damaged [[muscle fiber]]s, which increases the potential for growth of those fibers. This increase in myonuclei probably stems from creatine's ability to increase levels of the myogenic transcription factor MRF4.<ref>{{cite journal |last=Hespel |first=P |coauthors=Eijnde BO, Derave W, Richter EA |title=Creatine supplementation: exploring the role of the creatine kinase/phosphocreatine system in human muscle |journal=Canadian Journal of Applied Physiology |volume=26 |issue=Suppl. |pages=S79–102 |publisher=Human Kinetics Publishers, Inc. |year=2001 |pmid =11897886 }}</ref><ref>{{cite journal |last=Olsen |first=S |coauthors=Aagaard P, Fawzi K, et al. |title=Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training |journal=The Journal of Physiology |volume=573 |issue=Jun 1 |pages=525–34 |year=2006 |url=http://jp.physoc.org/cgi/content/abstract/573/2/525 |doi=10.1113/jphysiol.2006.107359 |pmid=16581862 |pmc=1779717}}</ref> In another study, researchers concluded that changes in substrate oxidation may influence the inhibition of fat mass loss associated with creatine after weight training when they discovered that fat mass did not change significantly with creatine but decreased after the placebo trial in a 12-week study on ten active men. The study also showed that [[One rep maximum|1-RM]] bench press and total body mass increased after creatine, but not after placebo.<ref>{{cite journal |last=Huso |first=ME |coauthors=Hampl JS, Johnston CS, Swan PD |title=Creatine supplementation influences substrate utilization at rest |journal=Journal of Applied Physiology |volume=93 |issue=6 |pages=2018–22 |date=2002-08-16 |url= http://jap.physiology.org/cgi/content/full/93/6/2018 |pmid=12391059 |doi=10.1152/japplphysiol.01170.2001}}</ref> The underlying effect of creatine on body composition has yet to be determined, as another study with a similar timeframe suggests no effect on body composition, but had less overall emphasis on metabolic effects.<ref>{{cite journal |last=Huso |first=ME |coauthors=Hampl JS, Johnston CS, Swan PD |title=Effect of in-season creatine supplementation on body composition and performance in rugby union football players |journal=Applied physiology, nutrition, and metabolism |volume=32 |issue=6 |pages=1052–7 |date=2007-12-01 |pmid=18059577 |doi=10.1139/H07-072}}</ref> There are two scientifically proven ways to supplement with creatine. The first is through a loading phase, in which 20&nbsp;grams is taken for 5–7 days, followed by a maintenance phase of 3-5&nbsp;grams a day for periods of 2–3 months at a time. The second consists of taking 3-10&nbsp;grams of creatine per day for a period of 2–3 months with no loading phase. It is generally recommended to take at least 1–2 weeks off from creatine supplementation in order to maintain a proper response mechanism in the body.<ref>{{cite web|url= http://www.exrx.net/Nutrition/Supplements/Creatine.html |title=Creatine |accessdate=2010-03-29}}</ref> Creatine use is not considered [[Doping (sport)|doping]] and is not banned by the majority of sport-governing bodies. However, in the [[United States]], the [[National Collegiate Athletic Association|NCAA]] recently ruled that colleges could not provide creatine supplements to their players, though the players are still allowed to obtain and use creatine independently. Creatine increases the conversion rate from [[testosterone]] to [[dihydrotestosterone]] in the body.<ref name="Van der Merwe, Johann; Brooks, Naomi E; Myburgh, Kathryn H 2009 399–404">{{cite journal |author=Van der Merwe, Johann; Brooks, Naomi E; Myburgh, Kathryn H |title=[Three Weeks of Creatine Monohydrate Supplementation Affects Dihydrotestosterone to Testosterone Ratio in College-Aged Rugby Players] |journal=Clinical Journal of Sport Medicine |volume=19 |issue=5 |pages=399–404 |year=2009 |pmid=19741313 |doi=10.1097/JSM.0b013e3181b8b52f}}</ref> A 2009 study showed that after a 7 day loading phase of creatine supplementation, followed by a further 14 days of creatine maintenance supplementation, while testosterone levels in blood serum were unchanged, levels of dihydrotestosterone increased by 56% after the initial 7 days of creatine loading and remained 40% above baseline after 14 days maintenance. The ratio of dihydrotestosterone to testosterone also increased by 36% after 7 days creatine supplementation and remained elevated by 22% after the maintenance dose.<ref name="Van der Merwe, Johann; Brooks, Naomi E; Myburgh, Kathryn H 2009 399–404"/> This could explain the fact that creatine users tend to report a slight onset of acne after starting creatine supplementation.{{Citation needed|date=August 2010}} It could also be a factor when it comes to the increased athletic performance that has been correlated with creatine supplemenation, although dihydrotestosterone has only minor anabolic effects compared to testosterone.{{Citation needed|date=August 2010}} ===Creatine ethyl ester=== {{Main|Creatine ethyl ester}} CEE is a form of commercially available creatine touted to have higher absorption rates and a longer serum half-life than regular creatine monohydrate by several supplement companies. However, no peer-reviewed studies have emerged on creatine ethyl ester which conclusively prove these claims. A study presented at the 4th International Society of Sports Nutrition (ISSN) annual meeting demonstrated that the addition of the ethyl group to creatine actually reduces acid stability and accelerates its breakdown to [[creatinine]]. The researchers concluded that creatine ethyl ester is inferior to [[creatine monohydrate]] as a source of creatine.<ref>[http://www.cr-technologies.net/cee.html Child, R. & Tallon, M.J. (2007). Creatine ethyl ester rapidly degrades to creatinine in stomach acid. International Society of Sports Nutrition 4th Annual Meeting]</ref> As a supplement, the compound was patented, and licensed through [[UNeMed]], the technology transfer entity of the [[University of Nebraska Medical Center]].<ref>[http://webmedia.unmc.edu/unemed/AnnualReports/UNeMedAnnualReview2003.pdf UNeMed 2003 Annual Report, p.4]</ref> ===Creatine hydrochloride=== {{Main|Creatine hydrochloride}} CrHCl is a hydrochloride [[salt_(chemistry)|salt]] patented in 2009 and marketed as an athletic and bodybuilding supplement. A study by Vireo Systems (commissioned by supplement manufacturer ProMera Health) found CrHCl to be 59 times more soluble in water than creatine monohydrate.<ref name="ConCretFAQ">{{cite web |url=http://www.con-cret.com/faq.asp |title=CON-CRET: FAQ |author=ProMera Health |accessdate=19 February 2011}}</ref> Due to its higher solubility, the recommended dosage for CrHCl is much lower than that for creatine monohydrate. ==Manufacture== <!-- **************************To whomever is editing this, I appreciate your contribution, but maybe consider moving this to the 'creatine' article rather than the 'creatine supplements' article *********************-->Synthetic creatine is usually made from [[sarcosine]] (Sarcosine salts) and [[cyanamide]]. Sarcosine is a naturally occurring amino acid like creatine, but manufacturers use a synthetic version. Sarcosine is usually made from [[chloroacetic acid]]. Sarcosine is N-methylglycine (H3C-NH-CH2-COOH) which is also an endogenous antagonist of glycine transporter-1. Cyanamide is an amide of [[cyanogen]], and has white crystalline composition. The creatine made from sarcosine and cyanamise is made in a glass-lined vat called a reactor. Because of the cost of manufacturing reactors and the need for specialist technicians, most synthetic creatine is made by a few firms, which resell to a number of retailers. The reactor has a big rod-like whisk that shoots into the mix to agitate it. The reactor is filled with water, the sarcosine and cyanamide are put in with [[catalyst]] compounds. The reactor is heated and pressurized, causing synthetic creatine crystals to form.<ref>http://tnation.t-nation.com/free_online_forum/diet_performance_nutrition_supplements/how_is_creatine_made Creatine Manufacture Process</ref> The crystalline creatine is then [[centrifuge|centrifuged]] to spin out undesirable by-products like [[creatinine]] and [[di-cyandiamide]] and subsequently [[Drying|vacuum dried]]. The dried creatine compound is milled into a fine powder for improved [[bioabsorption]]. Milling techniques differ, resulting in final products of varying [[solubility]] and bioabsorbability. For instance, creatine compounds milled to [[200 mesh]] are referred to as [[micronized]]. ==Safety== Current studies indicate that short-term creatine supplementation in healthy individuals is safe, although those with [[renal disease]] should avoid it due to possible risks of renal dysfunction, and before using it healthy users should bear these possible risks in mind.<ref name=Graham/><ref>[http://www.creatinemonohydrate.net/creatine_newsletter_12.html Creatine's Side Effects. Fact or Fiction?], An interview of Professor Jacques R. Poortmans</ref><ref>{{cite journal | title=Adverse effects of creatine supplementation. Fact or Fiction? | author=Poortmans J. R., Francaux, M. | journal= Sports Medicine | pmid=10999421 |month=September | year=2000 | doi=10.2165/00007256-200030030-00002 | volume=30 | pages=155–70 | issue=3}}</ref><ref>{{cite journal|last =Robinson|first =T.M.|coauthors =Sewell, D.A., Casey, A., Steenge, G. & Greenhaff, P.L.|title =Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function|journal =British Journal of Sports Medicine|volume =34|issue=4|pages =284–288|year=2000| url= http://bjsm.bmj.com/cgi/content/abstract/34/4/284 | accessdate = 2007-04-12|doi =10.1136/bjsm.34.4.284|pmid =10953902|pmc =1724224}}</ref> Small-scale, longer-term studies have been done and seem to demonstrate its safety.<ref>{{cite journal | author=Mayhew DL, Mayhew JL, Ware JS | title=Effects of long-term creatine supplementation on liver and kidney functions in American college football players. | journal=Int J Sport Nutr Exerc Metab. | volume=12 | issue=4 | year=2002 | pages=453–60 | pmid=12500988}}</ref><ref>{{cite journal|last =Poortmans|first =J.R.|coauthors =Francaux, M. |title =Long-term oral creatine supplementation does not impair renal function in healthy athletes| jou22469320296| accessdate = 2007-04-12| pmid =12701816 }}</ref> There have been reports of [[Cramp|muscle cramping]] with the use of creatine, though a study showed no reports of muscle cramping in subjects taking creatine-containing son a 15-item panel of qualitative urine markers. Proper hydration will ensure no cramping occurs due to creatine<ref>{{cite web|url=http://examine.com/supplements/Creatine/ |title=Examine.com - Creatine}}</ref>. Creatine did not cause any clinically significant changes in serum metabolic markers, muscle and liver enzyme efflux, serum electrolytes, blood lipid profiles, red and white whole blood cell hematology, or quantitative and qualitative urinary markers of renal function.<ref name="Kreider 95–104">{{cite journal| last =Kreider | first =R.B.| coauthors =Melton, C., Rasmussen, C.J., Greenwood, M., Lancaster, S., Cantler, E.C., Milnor, P. & Almada, A.L. | title =Long-term creatine supplementation does not significantly affect clinical markers of health in athletes | journal =Molecular and Cellular Biochemistry| volume =244| issue =1-2| pages =95–104| publisher =Springer Netherlands|date=2004-11-01| url= http://www.springerlink.com/content/t53405x65841411l |doi=10.1023/A:1022469320296| accessdate = 2007-04-12| pmid =12701816 }}</ref> In addition, experiments have shown that creatine supplementation improved the health and lifespan of mice.<ref>{{cite journal |author=Bender A, Beckers J, Schneider I, ''et al.'' |title=Creatine improves health and survival of mice |journal=Neurobiol. Aging |volume=29 |issue=9 |pages=1404–11 |year=2008 |month=September |pmid=17416441 |doi=10.1016/j.neurobiolaging.2007.03.001}}</ref> Whether these beneficial effects would also apply to humans is still uncertain. Studies have not yet determined if creatine supplementation will accelerate the growth of cysts in humans with [[Polycystic Kidney Disease]]. PKD is prevalent in approximately 1 in 1000 people and may not be detectable until affected individuals reach their thirties. ==Creatine and mental performance== Creatine administration was shown to significantly improve performance in cognitive and memory tests in vegetarian individuals involved in [[double-blind]], placebo-controlled cross-over trials.<ref name=RaeC/> Vegetarian supplementation with creatine seems to be especially beneficial as they appear to have lower average body stores, since meat is a primary source of dietary creatine.<ref name=RaeC>{{cite journal |author=Rae C, Digney AL, McEwan SR, Bates TC |title=Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial |journal=Proc Biol Sci. |volume=270 |issue=1529 |pages=2147–50 |year=2003 |month= October|pmid=14561278 |pmc=1691485 |doi=10.1098/rspb.2003.2492}}</ref> ==References== {{Reflist|2}} {{Dietary supplement}} {{DEFAULTSORT:Creatine Supplements}} [[Category:Bodybuilding supplements]] [[Category:Dietary supplements]] [[bg:???????]] [[ru:??????????? ???????]] [[tr:Kreatin destekleri]] [[zh:????]]'