clarifying the creatine myth by steven s. plisk,

8/12/2019 Clarifying The Creatine Myth by Steven S. Plisk,

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Clarifying The Creatine Myth

Steven S. Plisk, MS, CSCS.Richard B. Kreider, PhD, FACSM, MX

[Lanny: if necessary please correct the first paragraph explaining how the article was paraphrased/adapted.]

An article entitled The Creatine Mythwas published in the April 2000 issue of Wrestling U.S.A. Magazine. Thisarticle was adapted from a guest editorial by Plisk originally appearing two years earlier in the NCAA News (22), butwithout the authors input. We respect the need to paraphrase and condense this information, and most of whatappears in The Creatine Myth is accurate. However, some statements were changed significantly enough to affecttheir meaning, and a few of these were quoted and criticized by Matt Brzycki in his rebuttal in the January &February 2001 issues. He has also challenged some of our research findings.

Matt didnt address his comments to us before going public with them, compounding the problem. Had he done so,he would have known that hes trying to discredit some statements that were never made. He has also presented somecreative interpretations of the evidence, and raised some interesting questions in the process. We would like toaddress these issues, as they have significant implications for the wrestling community.Creatines Effect On Performance

The original NCAA News editorial by Plisk states the following (22): Athletes know that creatine is legal and readilyavailable, and that it works. They have experienced or seen these results first-hand, and many are aware of theresearch demonstrating its effect on metabolic power, capacity and recoverability as well as muscle mass andstrength. In the abbreviated version in Wrestling U.S.A., metabolic power, capacity and recoverabilitywas rephrasedsimply as endurance. Matt has taken issue with this because creatine has not been shown to enhance submaximalendurance performance. Actually, a review of the literature reveals that about half the studies looking at creatineseffect on aerobic capacity report significant improvements (1,3-11,13-21,24-27,29-34). This is not surprisingconsidering its role in the phosphocreatine circuit (a metabolic pathway that acts as the cells energy conduit and fluxcapacitor).

If Matt feels that either of us is unclear on this issue, we invite him to read the manuscript we co-authored in theFebruary 1999 issue of Strength & Conditioning Journal (23) as well as the recent book by Williams, Kreider &Branch (32). To clarify, short-term creatine supplementation can improve:

maximal strength and power [5-15%], and work performed during sets of maximal efforts [5-15%] single-effort sprint performance [1-5%], and work performed during repetitive sprints [5-15%]

The higher the intensity and/or briefer the recovery, the greater creatines effect on power and work output in single or repeated maximal efforts. Its effect is less pronounced when recovery is prolonged [e"5 min]. Over the long term,creatine can also promote significantly greater gains in strength, sprint performance and lean mass during training thanin matched-paired controls.

Mat t has also taken issue with creatine s documented effects on muscle mass and strength during training.Throughout his two-part article, he cites partial information from various studies to support his view that the

literature is inconclusive. Since the authors names and publication volumes/issues are omitted, however, theseresources cant be identified. In any case, they represent a minority of the published research examining this topic.

Dont take our word for it: Interested readers are encouraged to review the literature cited above for a balanced perspective. Some well-controlled studies have shown that there are non-responders to creatine supplementat ion.But the predominant trend is for creatine to improve certain parameters of strength, mass and/or sprint capacity.About two-thirds of the 350+ published studies on creatines effect on performance report statistically significantresults; whereas those with non-significant results often report improvements of 1-10% that dont meet the p


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Is creatine effective across the full spectrum of athletic activities? No. Is it for everyone? Probably not, as will bediscussed below.

ACSM Consensus Statement

A notable event occurred in Indianapolis in April 1999. The American College of Sports Medicine conducted anofficial roundtable, and subsequently published a consensus document entitled Physiological and Health Effects of Oral Creatine Supplementationin the March 2000 issue of their official journal, Medicine & Science in Sports &Exercise (26). This document reviewed the literature published up to that point, and concluded that creatine canenhance:

strength gains (in conjunction with body mass) in strength training programs exercise performance in brief, powerful activities, especially during repeated bouts

Matt refers to this document elsewhere in his article, in regard to the ACSMs cautionary remarks about unknown potential effects of high-dose supplementation, and limited data on long-term benefits and risks. However, he ignorestheir conclusion regarding creatines effect on strength gain during training; as well as the fact that its use hasnt beenlinked to gastrointestinal, renal and/or muscle cramping complications (also discussed below). The ACSM is aconservative organization in terms of what it states in its official documents, and its safe to say that the committee

overseeing this project would not have drawn these conclusions about creatines training effects if the evidence wereinconclusive.

The ACSMs conservative view is also evident in the way the committee follows each conclusion about creatineseffectiveness and safety with cautionary paragraphs that arent supported by the data. Furthermore, many of their concerns have been examined in detail since this report was published. These studies indicate that creatinesupplementation does not adversely affect heat tolerance, hydration, renal function, or muscle injuries in healthysubjects during training (1,3,24,30,33,34).

The Laboratory vs. The Real World?

At the conclusion of the first part of his article , Matt makes the following comment: Collectively, this solidresearch shows that any improved performance that may occur in laboratory settings does not translate intoimproved performance in realistic situations. Recent research has proven this criticism to be obsolete andshortsighted. For example, some new studies indicate performance improvements in repetitive swimming, repetitiverunning, and intermittent soccer. Once again, interested readers are encouraged to review the current literature(1,3,24,30,33,34).

Water Retention?

In the second part of his article, Matt states that creatine can increase body mass, not lean-body mass or lean-musclemass. And the most likely reason for the increased body mass is primarily due to water retention (within skeletalmuscle cells). In fact, creatine has been reported to stimulate myofibrillar protein synthesis (2,6,12,28), with itsnormal resting concentrations usually at the low end of the range needed to maximize this effect (possibly accountingfor how the process can be augmented by elevated tissue creatine levels via supplementation).

Furthermore, the cellular swelling (a.k.a. volumizing) effect resulting from creatines osmotic activity may partiallyexplain the mechanism by which some hormones and amino acids regulate metabolic control, and in turn modulateanabolic activity via hydration status (16, 17, 27). The changes in muscle mass observed during chronic creatinesupplementation and training, and accompanying improvements in strength and power, argue against simple fluidretention.

Keep in mind that skeletal muscle is over 70% water. Thus, a 10 lb. gain in muscle tissue represents about 7 lbs. of fluid regardless of whether its augmented by creatine use. Matt failed to mention that the same studies reporting


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creatines effect on total body water also show that it doesnt affect the bodys percentage of water - in other words,the weight gained is normal and proportional in terms of fluid content.

For these reasons, it is simplistic and irresponsible to attribute creatine-assisted gains in body weight to transientwater retention. In the first place, such comments are misleading, and give rise to confusion about what creatine doesor doesnt do. More importantly, this particular comment opens the door for an Ill-just-cut-more-weight mentalityamong athletes competing in body weight classes. This brings us to a key point.

Implications For Wrestlers

Heres the take-home message:

Wrestling may not fall within the range of brief/powerful/repetitive activities that creatine use can enhance.

Wrestlers need to know how creatine use can affect body composition. Specifically, in addition to augmenting musclemass during strength training, studies examining creatines effect on hydration have shown that it may make it moredifficult to dehydrate, i.e. to cut weight.

Theres a very real issue in terms of whether creatine is an appropriate supplement to use in sports where you have tomake weight. It has nothing to do with being inherently good or bad; it has to do with how it works, and with the

nature of the sport. As pointed out by Plisk in the NCAA News: Wrestlers are a different breed of athlete whoembody a gritty attitude and do-what-it-takes mind set better than perhaps anyone else. If athletes (or coaches) areled to believe that creatine use simply causes temporary water retention, they may think its just a matter of cutting afew additional pounds before competition with a little extra time and effort. If they dont understand the documentedcreatine-hypertrophy link, they may be setting themselves up for serious health consequences. And so, which is thereal problem - creatine itself, or the misinformation about it?

Lets do a reali ty check: First, theres too much evidence documenting creatines effect on muscle mass to bedismissed as inconclusive. Second, the more extreme the weight-cutting methods, the greater the risk. With athleteshealth and safety at stake, we must be very careful to present clear, evidence-based information on this issue.

Other Health and Safety Issues

In the second part of his article, Matt makes some interesting observations that raise additional questions:He states that the large fluid shift into skeletal muscle (intracellular water retention) that is caused by creatinesupplementation is thought to dilute electrolytes, thereby increasing the potential for muscle cramps. Thought bywhom, based on what evidence? Studies evaluating the effects of creatine on electrolyte status have shown no effect,even during intense training in a hot environment.

He proposes an intriguing theory of dehydration/heat-related illness in which creatine could intensify an alreadydehydrated state, resulting in heightened thermal stress and a resultant life-threatening situationvia water retention,fluid shift into the muscle, and reduced plasma volume. Were curious if Matt is part of a research group that isinvestigating this hypothesis, and what evidence he can provide? In fact, about 10 studies show that athletes whotake creatine during intense training experience the same or a lower incidence of heat related problems and cramps thanthose not using creatine. Where is the evidence that creatine adversely effects heat tolerance, hydration status and/or cramping in athletes or other healthy subjects?

He states that it is speculated that the intracellular water retention related to the use of creatine increases theintramuscular pressure which could contribute to muscle strains and/or dysfunction. Speculated by whom, based onwhat evidence? Once again, where are the studies showing that creatine promotes such problems in healthy subjects?Several show that athletes taking creatine during intense training have the same (or lower) incidence of muscle injuriesthan those not using creatine.

He states that creatine may cause a variety of gastrointestinal disturbances. Perhaps so, if the product is impure, or not produced according to industry standards for quality control and assurance (23, 32). In fact, such reports in


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creatine studies are rare, and occur at a similar (or lower) rate than those associated with carbohydrate placebos. Acorresponding amount of meat is thought to produce a few gastrointestinal disturbances too. And so wouldnt it bemore accurate to state the opposite?

The what ifs about creatine are getting all the Press, and are being anecdotally reportedin non-peer reviewednewspapers and magazines by unqualified journalists who arent held accountable for checking their facts. What isnt

being reported in the popular media is the volume of medical and scientific research that has been conducted; anddocumentation about the antitumor, antiviral, antidiabetic, and protective effects (e.g., from tissue hypoxia, ischemia,and neurodegenerative or muscle damage) of creatine and its analogs (1, 3-11, 13-21, 24-27, 29-34). Where is theevidence of side effects other than weight gain in healthy subjects?

Comparing Creatine & Carbohydrate Loading

Matt has criticized the statement that it may be more appropriate to compare creatine supplementation with the practice of carbohydrate loading as a means of improving metabolic power and capacity than it is to compare it withbody-building supplements.(22) Perhaps our understanding of the creatine kinase system, phosphocreatine circuit,and effect of supplementation on intramuscular creatine/phosphocreatine pools differs from his. Once again, if hefeels that we have misinterpreted this issue, we invite him to read our discussion of it in Strength & ConditioningJournal (23), as well as the references cited there.

Citations and Qualifications

Finally, Matt does cite the authors names in one of the studies mentioned in his article: He tries to discredit amanuscript by Dr. Richard Kreider and colleagues in Medicine & Science in Sports & Exercise (18), where StevenPlisk participated as part of his research team (Matt repeatedly mentions this affiliation, three times in case you misstwo of them).

Matt challenges this study on the grounds that the experimental groups serum creatinine level and liver enzyme effluxare described as normal. Unfortunately he doesnt provide references to support his belief that their values areabnormal; nor does he indicate what population hes comparing our results with. Since he chose Wrestling USA as aforum to express his viewpoint, perhaps he would be courteous enough to share that information with its readers? (Ahint: non-athletes have lower serum enzyme and creatinine levels than athletes, especially distance runners, whose

values are typically higher than those we reported.) And since hydration status can also affect creatinine levels,maybe he could tie this in with his dehydration/heat illness theory?

Indeed, in light of Matts unique insights on creatine physiology and supplementation, perhaps he would also be sokind to share with us his extensive background in this area. Surely, he has advanced degrees and accreditedcertifications in the subjects of applied physiology, clinical nutrition, or related disciplines. He has demonstrated hisability to synthesize and communicate evidence-based knowledge on this topic; and likewise to critique every aspectof the investigative process, from obtaining research grants to interpreting results. He must therefore be a skilledresearch scientist, as well as practitioner, with ample first-hand experience publishing his findings in peer-reviewed

journals, presenting them at symposia, and making other contributions to the scientific and coaching communities.Possibly he serves on the editorial board of one or more organizations professional journals as well, participating inthe blind-review process of manuscripts submitted by other research groups. In any case, we would like clarification

on Matt Brzyckis qualifications as an expert on this subject.

References

1. Benzi G. Is there a rationale for the use of creatine either as nutritional supplementation or drug administration inhumans participating in a sport? Pharmacol. Res. 41(3): 255-264, 2000.

2. Bessman S.P., Savabi F. The role of the phosphocreatine energy shuttle in exercise and muscle hypertrophy. In:A.W. Taylor, P.D. Gollnick, H.J. Green, et al. (Editors), International Series On Sport Sciences, Volume 21:Biochemistry Of Exercise VII. Champaign IL: Human Kinetics, 1988; pp. 167-178.


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3. Casey A., Greenhaff P.L. Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? Amer. J. Clin. Nutr. 72(2 Suppl): 607S-617S, 2000.

4. Clark J.F. Creatine and phosphocreatine: a review of their use in exercise and sport. J. Athlet. Train. 32(1): 45-51,1997.

5. Clark J.F. Creatine: a review of its nutritional applications in sport. Nutr. 14(3): 322-324, 1998.

6. Conway M.A. & Clark J.F. (Editors) Creatine & Creatine Phosphate: Scientific & Clinical Perspectives. SanDiego CA: Academic Press, 1996.

7. Demant T.W., Rhodes E.C. Effects of creatine supplementation on exercise performance. Sports Med. 28(1): 49-60, 1999.

8. Greenhaff P.L. Creatine and its application as an ergogenic aid. Int. J. Sport Nutr. 5(2): S100-S110, 1995.

9. Greenhaff P.L. The nutritional biochemistry of creatine. Nutritional Biochem. 8: 610-618, 1997.

10. Haff G.G., Kirksey K.B., Stone M.H. Creatine supplementation. Strength Cond. J. 21(4): 13-23, 1999.

11. Hultman E., Greenhaff P. Creatine ingestion and exercise performance in humans. Strength Cond. 17(4): 14-15,

1995.

12. Jacobus W.E. & Ingwall J.S. (Editors) Heart Creatine Kinase: The Integration Of Isozymes For EnergyDistribution. Baltimore MD: Williams & Wilkins, 1980.

13a. Juhn M.S., Tarnopolsky M. Oral creatine supplementation and athletic performance: a critical review. Clin. J.Sport Med. 8(4): 286-297, 1998 [published erratum appears in Clin. J. Sport Med. 9(2): 62, 1999].

13b. Juhn M.S., Tarnopolsky M. Potential side effects of oral creatine supplementation: a critical review. Clin. J.Sport Med. 8(4): 298-304, 1998 [published erratum appears in Clin. J. Sport Med. 9(2): 62, 1999].

14. Kraemer W.J., Volek J.S. Current comment from the American College of Sports Medicine: creatinesupplementation; available online:

15. Kraemer W.J., Volek J.S. Creatine supplementation: its role in human performance. Clin. Sports Med. 18(3):651-666, ix, 1999.

16. Kreider R.B. Creatine supplementation: analysis of ergogenic value, medical safety, and concerns. J. Exer PhysiolOnline 1(1); available online http://www.css.edu/users/tboone2/asep/jan3.htm 1998.

17. Kreider R.B. Creatine, the next ergogenic supplement? Sportscience Training & Technology , Internet SocietyFor Sport Science; available online 1998.

18. Kreider R., et al. Effects of creatine supplementation on body composition, strength, and sprint performance.Med. Sci. Sports Exer. 30(1): 73-82, 1998.

19. Maughan R.J. Creatine supplementation and exercise performance. Int. J. Sport Nutr. 5(2): 94-101, 1995.

20. Mujika I., Padilla S. Creatine supplementation as an ergogenic aid for sports performance in highly trainedathletes: a critical review. Int. J. Sport Med. 18(7): 491-496, 1997.

21. Oopik V., Timpmann S., Medijainen L. The role and application of dietary creatine supplementation in increasing physical performance capacity. Biol. Sport 12(4): 197-212, 1995.

22. Plisk S.S. Focus on facts needed in creatine discussion (guest editorial). NCAA News 35(8): 4-5, 1998; availableonline "http://www.ncaa.org/news/19980223/comment.html"


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23. Plisk S.S., Kreider R.B. Creatine controversy? Strength Cond. J. 21(1): 14-23, 1999.

24. Poortmans J.R., Francaux M. Adverse effects of creatine supplementation: fact or fiction? Sports Med. 30(3):155-170, 2000.

25. Silber M. Creatines: creatine and phosphocreatine as pharmacosanation aids. Sportscience Encyclopedia Of Sports Medicine & Science; available online: http://www.sportsci.org/encyc/drafts/Creatine.doc 1998.

26. Terjung R.L., et al. Physiological and health effects of oral creatine supplementation [special communications:American College of Sports Medicine Roundtable]. Med. Sci. Sports Exer. 32(3): 706-717, 2000.

27. Volek J.S., Kraemer W.J. Creatine supplementation: its effect on human muscular performance and bodycomposition. J. Strength Cond. Res. 10(3): 200-210, 1996.

28. Walker J.B. Creatine: biosynthesis, regulation, and function. Adv. Enzymol. Rel. Areas Mol. Biol. 50: 177-242,1979.

29. Wallimann T., et al. The phosphocreatine circuit and creatine supplementation both come of age. In: A. Mori,M. Ishida & J.F. Clark (Editors), Guanidino Compounds In Biology & Medicine. London: Blackwell Science, 1999;

pp. 117-129.

30. Wallimann T. Multiple functions of creatine kinase for cellular energetics: a scientific rationale for creatinesupplementation. Institute for Cell Biology, Swiss Federal Institute of Technology; available online

clarifying the creatine myth by steven s. plisk,

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