Journal of the International Society
`of Sports Nutrition
`
`BioMed Central
`
`Open Access
`Commentary
`International Society of Sports Nutrition position stand: creatine
`supplementation and exercise
`Thomas W Buford, Richard B Kreider*, Jeffrey R Stout, Mike Greenwood,
`Bill Campbell, Marie Spano, Tim Ziegenfuss, Hector Lopez, Jamie Landis and
`Jose Antonio
`
`Address: International Society of Sports Nutrition, 600 Pembrook Drive, Woodland Park, CO 80863, USA
`
`Email: Thomas W Buford - thomas_buford@baylor.edu; Richard B Kreider* - Richard_Kreider@baylor.edu; Jeffrey R Stout - jrstout@ou.edu;
`Mike Greenwood - Mike_Greenwood@baylor.edu; Bill Campbell - Campbell@coedu.usf.edu; Marie Spano - mariespano@comcast.net;
`Tim Ziegenfuss - tim@ohioresearchgroup.com; Hector Lopez - hlopezmd@gmail.com; Jamie Landis - jlandis@lakelandcc.edu;
`Jose Antonio - exphys@aol.com
`* Corresponding author
`
`Published: 30 August 2007
`
`Journal of the International Society of Sports Nutrition 2007, 4:6
`6
`
`doi:10.1186/1550-2783-4-
`
`This article is available from: http://www.jissn.com/content/4/1/6
`
`Received: 13 August 2007
`Accepted: 30 August 2007
`
`© 2007 Buford et al; licensee BioMed Central Ltd.
`This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
`which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
`
`A Position Statement and Review of the
`Literature
`Position Statement: The following nine points related
`to the use of creatine as a nutritional supplement con-
`stitute the Position Statement of the Society. They have
`been approved by the Research Committee of the Soci-
`ety.
`
`1. Creatine monohydrate is the most effective ergogenic
`nutritional supplement currently available to athletes in
`terms of increasing high-intensity exercise capacity and
`lean body mass during training.
`
`2. Creatine monohydrate supplementation is not only
`safe, but possibly beneficial in regard to preventing injury
`and/or management of select medical conditions when
`taken within recommended guidelines.
`
`3. There is no scientific evidence that the short- or long-
`term use of creatine monohydrate has any detrimental
`effects on otherwise healthy individuals.
`
`4. If proper precautions and supervision are provided,
`supplementation in young athletes is acceptable and may
`provide a nutritional alternative to potentially dangerous
`anabolic drugs.
`
`5. At present, creatine monohydrate is the most exten-
`sively studied and clinically effective form of creatine for
`use in nutritional supplements in terms of muscle uptake
`and ability to increase high-intensity exercise capacity.
`
`6. The addition of carbohydrate or carbohydrate and pro-
`tein to a creatine supplement appears to increase muscu-
`lar retention of creatine, although
`the effect on
`performance measures may not be greater than using cre-
`atine monohydrate alone.
`
`7. The quickest method of increasing muscle creatine
`stores appears to be to consume ~0.3 grams/kg/day of cre-
`atine monohydrate for at least 3 days followed by 3–5 g/
`d thereafter to maintain elevated stores. Ingesting smaller
`amounts of creatine monohydrate (e.g., 2–3 g/d) will
`increase muscle creatine stores over a 3–4 week period,
`however, the performance effects of this method of sup-
`plementation are less supported.
`
`8. Creatine products are readily available as a dietary sup-
`plement and are regulated by the U.S. Food and Drug
`Administration (FDA). Specifically, in 1994, U.S. President
`Bill Clinton signed into law the Dietary Supplement
`Health and Education Act (DSHEA). DSHEA allows man-
`ufacturers/companies/brands to make structure-function
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`claims; however, the law strictly prohibits disease claims
`for dietary supplements.
`
`guidelines may be established and unfounded fears
`diminished in regard to its use.
`
`9. Creatine monohydrate has been reported to have a
`number of potentially beneficial uses in several clinical
`populations, and further research is warranted in these
`areas.
`
`The following literature review has been prepared by the
`authors in support of the aforementioned position state-
`ment.
`
`Creatine Supplementation and Exercise: A
`Review of the Literature
`Introduction
`The use of creatine as a sport supplement has been sur-
`rounded by both controversy and fallacy since it gained
`widespread popularity in the early 1990's. Anecdotal and
`media reports have often claimed that creatine usage is a
`dangerous and unnecessary practice; often linking creat-
`ine use to anabolic steroid abuse [1]. Many athletes and
`experts in the field have reported that creatine supplemen-
`tation is not only beneficial for athletic performance and
`various medical conditions but is also clinically safe [2-5].
`Although creatine has recently been accepted as a safe and
`useful ergogenic aid, several myths have been purported
`about creatine supplementation which include:
`
`1. All weight gained during supplementation is due to
`water retention.
`
`2. Creatine supplementation causes renal distress.
`
`3. Creatine supplementation causes cramping, dehydra-
`tion, and/or altered electrolyte status.
`
`4. Long-term effects of creatine supplementation are com-
`pletely unknown.
`
`5. Newer creatine formulations are more beneficial than
`creatine monohydrate (CM) and cause fewer side effects.
`
`6. It's unethical and/or illegal to use creatine supplements.
`
`While these myths have been refuted through scientific
`investigation, the general public is still primarily exposed
`to the mass media which may or may not have accurate
`information. Due to this confounding information, com-
`bined with the fact that creatine has become one of the
`most popular nutritional supplements on the market, it is
`important to examine the primary literature on supple-
`mental creatine ingestion in humans. The purpose of this
`review is to determine the present state of knowledge con-
`cerning creatine supplementation, so that reasonable
`
`Background
`Creatine has become one of the most extensively studied
`and scientifically validated nutritional ergogenic aids for
`athletes. Additionally, creatine has been evaluated as a
`potential therapeutic agent in a variety of medical condi-
`tions such as Alzheimer's and Parkinson's diseases. Bio-
`chemically
`speaking,
`the
`energy
`supplied
`to
`rephosphorylate adenosine diphosphate (ADP) to adeno-
`sine triphosphate (ATP) during and following intense
`exercise is largely dependent on the amount of phospho-
`creatine (PCr) stored in the muscle [6,7]. As PCr stores
`become depleted during intense exercise, energy availabil-
`ity diminishes due to the inability to resynthesize ATP at
`the rate required to sustained high-intensity exercise [6,7].
`Consequently, the ability to maintain maximal-effort
`exercise declines. The availability of PCr in the muscle
`may significantly influence the amount of energy gener-
`ated during brief periods of high-intensity exercise. Fur-
`thermore, it has been hypothesized that increasing muscle
`creatine content, via creatine supplementation, may
`increase the availability of PCr allowing for an accelerated
`rate of resynthesis of ATP during and following high-
`intensity, short-duration exercise [6-12]. Theoretically,
`creatine supplementation during training may lead to
`greater training adaptations due to an enhanced quality
`and volume of work performed. In terms of potential
`medical applications, creatine is intimately involved in a
`number of metabolic pathways. For this reason, medical
`researchers have been investigating the potential thera-
`peutic role of creatine supplementation in a variety of
`patient populations.
`
`Creatine is chemically known as a non-protein nitrogen; a
`compound which contains nitrogen but is not a protein
`per se [13]. It is synthesized in the liver and pancreas from
`the amino acids arginine, glycine, and methionine
`[9,13,14]. Approximately 95% of the body's creatine is
`stored in skeletal muscle. Additionally, small amounts of
`creatine are also found in the brain and testes [8,15].
`About two thirds of the creatine found in skeletal muscle
`is stored as phosphocreatine (PCr) while the remaining
`amount of creatine is stored as free creatine [8]. The total
`creatine pool (PCr + free creatine) in skeletal muscle aver-
`ages about 120 grams for a 70 kg individual. However, the
`average human has the capacity to store up to 160 grams
`of creatine under certain conditions [7,9]. The body
`breaks down about 1 – 2% of the creatine pool per day
`(about 1–2 grams/day) into creatinine in the skeletal
`muscle [13]. The creatinine is then excreted in urine
`[13,16]. Creatine stores can be replenished by obtaining
`creatine in the diet or through endogenous synthesis of
`creatine from glycine, arginine, and methionine [17,18].
`
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`Dietary sources of creatine include meats and fish. Large
`amounts of fish and meat must be consumed in order to
`obtain gram quantities of creatine. Whereas dietary sup-
`plementation of creatine provides an inexpensive and effi-
`cient means of increasing dietary availability of creatine
`without excessive fat and/or protein intake.
`
`Supplementation Protocols and Effects on Muscle
`Creatine Stores
`Various supplementation protocols have been suggested
`to be efficacious in increasing muscle stores of creatine.
`The amount of increase in muscle storage depends on the
`levels of creatine in the muscle prior to supplementation.
`Those who have lower muscle creatine stores, such as
`those who eat little meat or fish, are more likely to experi-
`ence muscle storage increases of 20–40%, whereas those
`with relatively high muscle stores may only increase stores
`by 10–20% [19]. The magnitude of the increase in skeletal
`muscle creatine content is important because studies have
`reported performance changes to be correlated to this
`increase [20,21].
`
`The supplementation protocol most often described in
`the literature is referred to as the "loading" protocol. This
`protocol is characterized by ingesting approximately 0.3
`grams/kg/day of CM for 5 – 7 days (e.g., ⯝5 grams taken
`four times per day) and 3–5 grams/day thereafter [18,22].
`Research has shown a 10–40% increase in muscle creatine
`and PCr stores using this protocol [10,22]. Additional
`research has reported that the loading protocol may only
`need to be 2–3 days in length to be beneficial, particularly
`if the ingestion coincides with protein and/or carbohy-
`drate [23,24]. Furthermore, supplementing with 0.25
`grams/kg-fat free mass/day of CM may be an alternative
`dosage sufficient to increase muscle creatine stores [25].
`
`Other suggested supplementation protocols utilized
`include those with no loading phase as well as "cycling"
`strategies. A few studies have reported protocols with no
`loading period to be sufficient for increasing muscle crea-
`tine (3 g/d for 28 days) [15] as well as muscle size and
`strength (6 g/d for 12 weeks) [26,27]. These protocols
`seems to be equally effective in increasing muscular stores
`of creatine, but the increase is more gradual and thus the
`ergogenic effect does not occur as quickly. Cycling proto-
`cols involve the consumption of "loading" doses for 3–5
`days every 3 to 4 weeks [18,22]. These cycling protocols
`appear to be effective in increasing and maintaining mus-
`cle creatine content before a drop to baseline values,
`which occurs at about 4–6 weeks [28,29].
`
`Creatine Formulations and Combinations
`Many forms of creatine exist in the marketplace, and these
`choices can be very confusing for the consumer. Some of
`these formulations and combinations include creatine
`
`creatine + β-hydroxy-β-methlybutyrate
`phosphate,
`(HMB), creatine + sodium bicarbonate, creatine magne-
`sium-chelate, creatine + glycerol, creatine + glutamine,
`creatine + β-alanine, creatine ethyl ester, creatine with cin-
`nulin extract, as well as "effervescent" and "serum formu-
`lations". Most of these forms of creatine have been
`reported to be no better than traditional CM in terms of
`increasing strength or performance [30-38]. Reliable stud-
`ies are yet to be published for creatine ethyl ester and cre-
`atine with cinnulin extract. Recent studies do suggest,
`however, that adding β-alanine to CM may produce
`greater effects than CM alone. These investigations indi-
`cate that the combination may have greater effects on
`strength, lean mass, and body fat percentage; in addition
`to delaying neuromuscular fatigue [31,32].
`
`Three alternative creatine formulations have shown
`promise, but at present do not have sufficient evidence to
`warrant recommendation in lieu of CM. For example, cre-
`atine phosphate has been reported to be as effective as CM
`at improving LBM and strength, [36] yet this has only
`been reported in one study. In addition, creatine phos-
`phate is currently more difficult and expensive to produce
`than CM. Combining CM with sodium phosphate, which
`has been reported to enhance high-intensity endurance
`exercise, may be a more affordable alternative to creatine
`phosphate. Secondly, a creatine/HMB combination was
`reported to be more effective at improving LBM and
`strength than either supplement alone [39], but other data
`has reported the combination offers no benefit in terms of
`increasing aerobic or anaerobic capacity [40,41]. The con-
`flicting data therefore do not warrant recommendation of
`the creatine/HMB combination in lieu of CM. Lastly, cre-
`atine + glycerol has been reported to increase total body
`water as a hyper-hydration method prior to exercise in the
`heat, but this is also the first study of its kind. In addition,
`this combination failed to improve thermal and cardio-
`vascular responses to a greater extent than CM alone [42].
`
`The addition of nutrients that increase insulin levels and/
`or improve insulin sensitivity has been a major source of
`interest in the last few years by scientists looking to opti-
`mize the ergogenic effects of creatine. The addition of cer-
`tain macronutrients appears to significantly augment
`muscle retention of creatine. Green et al. [24] reported
`that adding 93 g of carbohydrate to 5 g of CM increased
`total muscle creatine by 60%. Likewise, Steenge et al. [23]
`reported that adding 47 g of carbohydrate and 50 g of pro-
`tein to CM was as effective at promoting muscle retention
`of creatine as adding 96 g of carbohydrate. Additional
`investigations by Greenwood and colleagues [30,43] have
`reported increased creatine retention from the addition of
`dextrose or low levels of D-pinitol (a plant extract with
`insulin-like properties). While the addition of these nutri-
`ents has proved to increase muscle retention, several
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`recent investigations have reported these combinations to
`be no more effective at improving muscle strength and
`endurance or athletic performance [44-46]. Other recent
`studies, however, have indicated a potential benefit on
`anaerobic power, muscle hypertrophy, and 1 RM muscle
`strength when combining protein with creatine [47,48]. It
`appears that combining CM with carbohydrate or carbo-
`hydrate and protein produces optimal results. Studies sug-
`gest that increasing skeletal muscle creatine uptake may
`enhance the benefits of training.
`
`Effects of Supplementation on Exercise Performance and
`Training Adaptations
`CM appears to be the most effective nutritional supple-
`ment currently available in terms of improving lean body
`mass and anaerobic capacity. To date, several hundred
`peer-reviewed research studies have been conducted to
`evaluate the efficacy of CM supplementation in improv-
`ing exercise performance. Nearly 70% of these studies
`have reported a significant improvement in exercise
`capacity, while the others have generally reported non-sig-
`nificant gains in performance [49]. No studies have
`reported an ergolytic effect on performance although
`some have suggested that weight gain associated with CM
`supplementation could be detrimental in sports such as
`running or swimming. The average gain in performance
`from these studies typically ranges between 10 to 15%
`depending on the variable of interest. For example, short-
`term CM supplementation has been reported to improve
`maximal power/strength (5–15%), work performed dur-
`ing sets of maximal effort muscle contractions (5–15%),
`single-effort sprint performance (1–5%), and work per-
`formed during repetitive sprint performance (5–15%)
`[49]. Long-term CM supplementation appears to enhance
`the overall quality of training, leading to 5 to 15% greater
`gains in strength and performance [49]. Nearly all studies
`indicate that "proper" CM supplementation increases
`body mass by about 1 to 2 kg in the first week of loading
`[19].
`
`The vast expanse of literature confirming the effectiveness
`of CM supplementation is far beyond the scope of this
`review. Briefly, short-term adaptations reported from CM
`supplementation include increased cycling power, total
`work performed on the bench press and jump squat, as
`well as improved sport performance in sprinting, swim-
`ming, and soccer [38,50-57]. Long-term adaptations
`when combining CM supplementation with training
`include increased muscle creatine and PCr content, lean
`body mass, strength, sprint performance, power, rate of
`force development, and muscle diameter [39,54-60]. In
`long-term studies, subjects taking CM typically gain about
`twice as much body mass and/or fat free mass (i.e., an
`extra 2 to 4 pounds of muscle mass during 4 to 12 weeks
`of training) than subjects taking a placebo [61-64]. The
`
`gains in muscle mass appear to be a result of an improved
`ability to perform high-intensity exercise via increased PCr
`availability and enhanced ATP synthesis, thereby enabling
`an athlete to train harder and promote greater muscular
`hypertrophy via increased myosin heavy chain expression
`possibly due to an increase in myogenic regulatory factors
`myogenin and MRF-4 [26,27,65]. The tremendous num-
`bers of investigations conducted with positive results from
`CM supplementation lead us to conclude that it is the
`most effective nutritional supplement available today for
`increasing high-intensity exercise capacity and building
`lean mass.
`
`Medical Safety of Creatine Supplementation
`While the only clinically significant side effect reported in
`the research literature is that of weight gain [4,18,22],
`many anecdotal claims of side effects including dehydra-
`tion, cramping, kidney and liver damage, musculoskeletal
`injury, gastrointestinal distress, and anterior (leg) com-
`partment syndrome still exist in the media and popular
`literature. While athletes who are taking CM may experi-
`ence these symptoms, the scientific literature suggests that
`these athletes have no greater, and a possibly lower, risk of
`these symptoms than those not supplementing with CM
`[2,4,66,67].
`
`Many of these fears have been generated by the media and
`data taken from case studies (n = 1). Poortmans and Fran-
`caux reported that the claims of deleterious effects of cre-
`atine supplements on renal function began in 1998 [68].
`These claims followed a report that creatine supplementa-
`tion was detrimental to renal glomerular filtration rate
`(GFR) in a 25-year-old man who had previously presented
`with kidney disease (glomerulosclerosis and corticoster-
`oid-responsive nephritic syndrome) [69]. Three days later,
`a French sports newspaper, L'Equipe, reported that supple-
`mental creatine is dangerous for the kidneys in any condi-
`tion [70]. Several European newspapers then picked up
`the "news" and reported the same. Since that time, other
`individual case studies have been published posing that
`CM supplementation caused deleterious effects on renal
`function [71,72].
`
`Much of the concern about CM supplementation and
`renal function has centered around concerns over
`increased serum creatinine levels. While creatinine does
`make up a portion of GFR and must be excreted by the
`kidneys, there is no evidence to support the notion that
`normal creatine intakes (< 25 g/d) in healthy adults cause
`renal dysfunction. In fact, Poortmans et al. have shown no
`detrimental effects of short- (5 days), medium- (14 days),
`or long-term (10 months to 5 years) CM supplementation
`on renal function [5,73,74]. Interestingly, Kreider et al. [4]
`observed no significant difference in creatinine levels
`between CM users and controls, yet most athletes (regard-
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`less of whether taking CM or not) had elevated creatinine
`levels along with proper clearance during intense training.
`The authors noted that if serum creatinine was examined
`as the sole measure of renal function, it would appear that
`nearly all of the athletes (regardless of CM usage) were
`experiencing renal distress. Although case studies have
`reported problems, these large-scale, controlled studies
`have shown no evidence indicating that CM supplemen-
`tation in healthy individuals is a detriment to kidney func-
`tioning.
`
`Another anecdotal complaint about supplemental creat-
`ine is that the long-term effects are not known. Wide-
`spread use of CM began in the 1990's. Over the last few
`years a number of researchers have begun to release results
`of long-term safety trials. So far, no long-term side effects
`have been observed in athletes (up to 5 years), infants
`with creatine synthesis deficiency (up to 3 years), or in
`clinical patient populations
`(up
`to 5
`years)
`[4,5,18,75,76]. One cohort of patients taking 1.5 – 3
`grams/day of CM has been monitored since 1981 with no
`significant side effects [77,78]. In addition, research has
`demonstrated a number of potentially helpful clinical
`uses of CM in heart patients, infants and patients with cre-
`atine synthesis deficiency, patients suffering orthopedic
`injury, and patients with various neuromuscular diseases.
`Potential medical uses of supplemental creatine have
`been investigated since the mid 1970s. Initially, research
`focused on the role of CM and/or creatine phosphate in
`reducing heart arrhythmias and/or improving heart func-
`tion during ischemic events [18]. Interest in medical uses
`of creatine supplements has expanded to include those
`with creatine deficiencies [79-81], brain and/or spinal
`cord injuries [82-86], muscular dystrophy [87-90], diabe-
`tes [91], high cholesterol/triglyceride levels [92], and pul-
`monary disease [93] among others. Although more
`research is needed to determine the extent of the clinical
`utility, some promising results have been reported in a
`number of studies suggesting that creatine supplements
`may have therapeutic benefit in certain patient popula-
`tions. In conjunction with short- and long-term studies in
`healthy populations, this evidence suggests that creatine
`supplementation appears to be safe when taken within
`recommended usage guidelines.
`
`Creatine Use in Children and Adolescents
`Opponents of creatine supplementation have claimed
`that it is not safe for children and adolescents [1]. While
`fewer investigations have been conducted in using
`younger participants, no study has shown CM to have
`adverse effects in children. In fact, long-term CM supple-
`mentation (e.g., 4 – 8 grams/day for up to 3 years) has
`been used as an adjunctive therapy for a number of creat-
`ine synthesis deficiencies and neuromuscular disorders in
`children. Clinical trials are also being conducted in chil-
`
`dren with Duschenne muscular dystrophy [87,88]. How-
`ever, as less is known about the effects of supplemental
`creatine on children and adolescents, it is the view of the
`ISSN that younger athletes should consider a creatine sup-
`plement only if the following conditions are met [19]:
`
`1. The athlete is past puberty and is involved in serious/
`competitive training that may benefit from creatine sup-
`plementation;
`
`2. The athlete is eating a well-balanced, performance-
`enhancing diet;
`
`3. The athlete and his/her parents understand the truth
`concerning the effects of creatine supplementation;
`
`4. The athlete's parents approve that their child takes sup-
`plemental creatine;
`
`5. Creatine supplementation can be supervised by the ath-
`letes parents, trainers, coaches, and/or physician;
`
`6. Quality supplements are used; and,
`
`7. The athlete does not exceed recommended dosages.
`
`If these conditions are met, then it would seem reasonable
`that high school athletes should be able to take a creatine
`supplement. Doing so may actually provide a safe nutri-
`tional alternative to illegal anabolic steroids or other
`potentially harmful drugs. Conversely, if the above condi-
`tions are not met, then creatine supplementation may not
`be appropriate. It appears that this is no different than
`teaching young athletes' proper training and dietary strat-
`egies to optimize performance. Creatine is not a panacea
`or short cut to athletic success. It can, however, offer some
`benefits to optimize training of athletes involved in
`intense exercise in a similar manner that ingesting a high-
`carbohydrate diet, sports drinks, and/or carbohydrate
`loading can optimize performance of an endurance ath-
`lete.
`
`The Ethics of Creatine
`Several athletic governing bodies and special interest
`groups have questioned whether it is ethical for athletes to
`take creatine supplements as a method of enhancing per-
`formance. Since research indicates that CM can improve
`performance, and it would be difficult to ingest enough
`creatine from food in the diet, they rationalize that it is
`unethical to do so. In this age of steroid suspicion in
`sports, some argue that if you allow athletes to take creat-
`ine, they may be more predisposed to try other dangerous
`supplements and/or drugs. Still others have attempted to
`directly lump creatine in with anabolic steroids and/or
`banned stimulants and have called for a ban on the use of
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`CM and other supplements among athletes. Finally, fresh
`off of the ban of dietary supplements containing ephedra,
`some have called for a ban on the sale of CM citing safety
`concerns. Creatine supplementation is not currently
`banned by any athletic organization although the NCAA
`does not allow institutions to provide CM or other "mus-
`cle building" supplements to their athletes (e.g., protein,
`amino acids, HMB, etc). In this case, athletes must pur-
`chase creatine containing supplements on their own. The
`International Olympic Committee considered these argu-
`ments and ruled that there was no need to ban creatine
`supplements since creatine is readily found in meat and
`fish and there is no valid test to determine whether ath-
`letes are taking it. In light of the research that has been
`conducted with CM, it appears that those who call for a
`ban on it are merely familiar with the anecdotal myths
`surrounding the supplement, and not the actual facts. We
`see no difference between creatine supplementation and
`ethical methods of gaining athletic advantage such as
`using advanced training techniques and proper nutri-
`tional methods. Carbohydrate loading is a nutritional
`technique used to enhance performance by enhancing
`glycogen stores. We see no difference between such a prac-
`tice and supplementing with creatine to enhance skeletal
`muscle creatine and PCr stores. If anything, it could be
`argued that banning the use of creatine would be unethi-
`cal as it has been reported to decrease the incidence of
`musculoskeletal
`injuries
`[2,66,75,94], heat
`stress
`[2,95,96],
`provide
`neuroprotective
`effects
`[82,83,85,97,98], and expedite rehabilitation from injury
`[86,99,100].
`
`Conclusion
`It is the position of the International Society of Sports
`Nutrition that the use of creatine as a nutritional supple-
`ment within established guidelines is safe, effective, and
`ethical. Despite lingering myths concerning creatine sup-
`plementation in conjunction with exercise, CM remains
`one of the most extensively studied, as well as effective,
`nutritional aids available to athletes. Hundreds of studies
`have shown the effectiveness of CM supplementation in
`improving anaerobic capacity, strength, and lean body
`mass in conjunction with training. In addition, CM has
`repeatedly been reported to be safe, as well as possibly
`beneficial in preventing injury. Finally, the future of crea-
`tine research looks bright in regard to the areas of trans-
`port mechanisms, improved muscle retention, as well as
`treatment of numerous clinical maladies via supplemen-
`tation.
`
`References
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