Creatine Mono Studies

I will place studies on Creatine Mono in here, for any one that doubts it or thinks it is unhealthy to use.

Introduction

While creatine has many applications to individuals of all gender, age, mental and physical abilities, this paper is written for young, healthy men who are active in sports or exercise. I have not taken into account the numerous studies done for children, the elderly and middle aged, or women when writing this article. All data and studies used in this paper are in reference to healthy men between the ages of 18-40, who participate in physical activity several times a week, unless otherwise stated.

Furthermore, I am neither a doctor, nor a pharmacologist. The information, views, and advice contained within this paper are for educational purposes only. Do not attempt any exercise plan, diet plan, or radical lifestyle change without first consulting with a physician. The material in this paper should not be construed for medical advice. Neither creatine, nor the methods of supplementation discussed within should be used to treat any condition or disease, unless instructed by a doctor.

Creatine

The compound creatine has been hyped by supplement companies and demonized by the media, and without proper study in the field of supplement pharmacology, Primary Care physicians cannot offer any relevant information to the consumer. It is not surprising that there is much confusion over the safety and effects of creatine.

Creatine is a naturally occurring substance in human and animal bodies. It is synthesized and consumed on a daily basis (the human liver can combine the amino acids Arginine, Glycine, and Methionine to synthesize creatine). The average 160 lb (72.5 kg) person stores approx. 120 grams of creatine in their body. 95-98% of that creatine is contained within muscle tissue, while the rest is stored within other body organs (including brain, heart and liver).

Creatine works by replenishing ATP. ATP (adenosine tri-phosphate) is an energy-containing compound. The body can break ATP into ADP (adenosine di-phosphate) and inorganic phosphate. This reaction releases energy, which can be used by the body to fuel explosive, short burst of strength. The metabolism of carbohydrates and fats take longer to convert into a useable energy source, so ATP is the most used energy source during these high intensity movements. There is only enough ATP for 10-15 seconds of maximum exertion, however, and so the problem arises as to how to free up more energy. ADP is itself useless as a source of energy, until it regains a phosphate atom. Creatine phosphate (CP), the form of creatine found mostly in muscles, reacts with ADP. The phosphate is freed from creatine and bonds with ADP to create ATP.

This purpose of creatine has been known for some time, however the benefits or downfalls of exogenous supplementation of creatine on physical performance, especially in the area of sports and exercise, has long been glorified, but up until the past few years never substantiated with hard science. The ignorance of health care professionals has obfuscated the subject of creatine supplementation, and for many people the only information they hear is the half-truths, propaganda, and lies of the media and supplement companies.

Many of the claims put forth about creatine’s safety focus on the idea that it may harm the kidneys and liver. This is false. Creatine does not harm the liver5, 24, 49, 80, or the kidneys1, 5, 8, 24, 49, 64, 80. Some of these claims stem from the idea that creatinine levels are increased with creatine supplementation (creatinine being a byproduct of renal failure). Creatinine, while sometimes slightly elevated, is always within normal and safe levels when creatine is used according to recommended guidelines2, 24, 29, 49, 64, 71, 80. A deleterious effect on cholesterol and lipid values is another popular argument by critics of the supplement. While not studied as much as other areas of safety, limited studies have shown no effect2, 5, or a positive effect of cholesterol4. Blood values during creatine supplementation have also been shown to be normal19, 49, 71, 80, as well as effects on mood51.

A common complaint among sports coaches and players is that creatine may increase injury rates. Some people have claimed this is due to increased musculoskeletal stiffness. No studies have reported any signs of increased injury with concomitant creatine use, and at least one has even tested the claim and shown that there are no negative musculoskeletal changes with creatine use75.

On the other side of the spectrum, there are many claims of performance enhancement with creatine use. Increased muscle mass2, 19, 26, 35, 37, 61, 71 is one proven effect of creatine use. Enhanced anaerobic capacity and strength has shown to be beneficially effected6, 9, 16, 19, 26, 27, 28, 33, 34, 37, 40, 41, 46, 51, 52, 56, 59, 60, 61, 65, 86 in all but one68 study. The overwhelming data supporting increased strength, and to a lesser degree muscle mass, makes creatine a wonder supplement. There are, however, many more benefits to creatine supplementation that puts this supplement a step above all others. Conflicting data shows that creatine may9, 10, 23, 69, 70 increase aerobic performance, or have no effect28, 50, 67, even though body mass increases. The fact that aerobic performance increases are possible in spite of increased body mass means that individuals training for endurance, speed and strength may benefit from creatine without risking negative changes in performance. Sprinting, studied in its numerous forms, also shows mixed results with regards to creatine. While some show no effect12, 15, 20, 42, 43, 53, 56, 63, 73 the majority of studies have shown marked increases in performance13, 19, 25, 28, 36, 38, 44, 57, 58, 62, 66, 79, 82. Isometric strength increases22 and isometric strength endurance21, anticatabolic47 and antioxidant31 properties, jumping improvements59, 75, exercise recovery77, 78, performance in hot conditions79, and time to neuromuscular fatigue81 are some of the other strength and endurance related benefits observed in some of the studies. These benefits also come with another bonus: body fat percentage has been shown to not change2, 61, 71 or decrease51 in several studies that looked at body composition.

Creatine may also assist injured individuals who are recovering from major injuries. After non-use and atrophy, creatine may increase GLUT-4 protein concentration and translocation at cell membranes30 as well as muscular performance recovery55. The intracellular water retention creatine creates11, 26 may also help maintain an anabolic environment and allow extra nutrient and glycogen to be stored in the recovering muscle. Even though creatine has been show in some studies to have no effect on hormone levels45, 49, one study studying Growth Hormone (GH) specifically has shown an increase (within high normal levels) of GH with creatine use. GH has anabolic properties, as well as healing properties, and this may be another benefit of using creatine to help speed recovery from an injury. Another benefit to individuals recovering from injury, and those that aren't, is that creatine may stimulate satellite cell differentiation32, which may increase muscle size and help heal injuries.

Creatine is also synergistic with many other substances. Creatine has shown positive effects with pyruvate3, whey protein17, caffeine18, carbohydrates34, 52, 74, l-glutamine37, and magnesium72. Creatine stacked with HMB has produced good results48, as well as no results14.

The dosing of creatine has also come into suspect since several animal studies with ultra high doses of creatine produced creatine receptor down regulation after several weeks of use. Considering these studies used extremely high doses of creatine, and with at least one study showing no down regulation with continued use in humans39, it appears now that cycling creatine is not needed to keep your gains. Loading creatine in several small portions throughout the day has given the best results and shown the most saturation of the muscle amino acid pool with creatine76, and may be the best way to take it during the loading phase.

Hopefully the stigma of creatine being a deadly drug that destroys organs, increases injuries and increases fat will go away now that there are so many studies showing the positive effects and lack of negative effects with supplementation.



1 Journal Article 20452050 Poortmans, J.R., Francaux, M., Adverse effects of creatine supplementation: fact or fiction? Sports Medicine (Auckland, N.Z.) 30 (3) 155-170 2000

2 Journal Article 20330694 Volek, J.S., Duncan, N.D., Mazzetti, S.A., Putukian, M., Gomez, A.L., Kraemer, W.J. No effect of heavy resistance training and creatine supplementation on blood lipids. International Journal of Sport Nutrition and Exercise Metabolism 10 (2) 144-156 2000

3 Journal Article 99290802 Stone, M.H., Sanborn, K., Smith, L.L., O_Bryant, H.S., Hoke, T., Utter, A.C., Johnson, R.L., Boros, R., Hruby, J., Pierce, K.C., Stone, M.E., Garner, B. Effects of in-season (5 weeks) creatine and pyruvate supplementation on anaerobic performance and body composition in American football players. International Journal of Sport Nutrition 9 (2) 146-165 1999

4 Journal Article 96370373 Earnest, C.P., Almada, A.L., Mitchell, T.L., High-performance capillary electrophoresis-pure creatine monohydrate reduces blood lipids in men and women. Clin Sci (Lond) 91 (1) 113-118 1996

5 Journal Article 22587383 Kreider, R.B., Melton, C., Rasmussen, C.J., Greenwood, M., Lancaster, S., Cantler, E.C., Milnor, P., Almada, A.L. Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. Molecular and Cellular Biochemistry 244 (1-2) 95-104 2003 Exercise and Sport Nutrition Laboratory, Department of Human Movement Sciences and Education, The University of Memphis, Memphis, TN, USA. Richard_Kreider@baylor.edu

6 Journal Article 20551468 Tarnopolsky, M.A., MacLennan, D.P., Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. International Journal of Sport Nutrition and Exercise Metabolism 10 (4) 452-463 2000

7 Journal Article 22587382 Kreider, R.B. Effects of creatine supplementation on performance and training adaptations. Molecular and Cellular Biochemistry 244 (1-2) 89-94 2003

8 Journal Article 22715635 Farquhar, W.B., Zambraski, E.J., Effects of creatine use on the athlete's kidney. Curr Sports Med Rep 1 (2) 103-106 2002

9 Journal Article 97440659 Prevost, M.C., Nelson, A.G., Morris, G.S. Creatine supplementation enhances intermittent work performance. Research Quarterly For Exercise and Sport 68 (3) 233-140 1997

10 Journal Article 96301882 Rossiter, H.B., Cannell, E.R., Jakeman, P.M. The effect of oral creatine supplementation on the 1000-m performance of competitive rowers. Journal of Sports Sciences 14 (2) 175-179 1996

11 Journal Article 22083817 Saab, G., Marsh, G.D., Casselman, M.A., Thompson, R.T. Changes in human muscle transverse relaxation following short-term creatine supplementation. Experimental Physiology 87 (3) 383-389 2002

12 Journal Article 97030401 Burke, L.M., Pyne, D.B., Telford, R.D. Effect of oral creatine supplementation on single-effort sprint performance in elite swimmers. International Journal of Sport Nutrition 6 (3) 222-233 1996

13 Journal Article 20040954 Jones, A.M., Atter, T., Georg, K.P. Oral creatine supplementation improves multiple sprint performance in elite ice-hockey players. The Journal of Sport Medicine and Physical Fitness 39 3 189-96 1999

14 Journal Article 22516303 O_Connor, D.M., Crowe, M.J. Effects of beta-hydroxy-beta-methylbutyrate and creatine monohydrate supplementation on the aerobic and anaerobic capacity of highly trained athletes. The Journal of Sport Medicine and Physical Fitness 43 (1) 64-68 2003

15 Journal Article 97030400 Redondo, D.R., Dowling, E.A., Graham, B.L., Almada, A.L., Williams, M.H. The effect of oral creatine monohydrate supplementation on running velocity. International Journal of Sport Nutrition 6 (3) 213-221 1996

16 Journal Article 21576121 Romer, L.M., Barrington, J.P., Jeukendrup, A.E. Effects of oral creatine supplementation on high intensity, intermittent exercise performance in competitive squash players. International Journal of Sports Medicine 22 (8) 546-552 2001

17 Journal Article 21475748 Burke, D.G., Chilibeck, P.D., Davidson, K.S., Candow, D.G., Farthing, J., Smith_Palmer, T. The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength. International Journal of Sport Nutrition and Exercise Metabolism 11 (3) 349-364 2001 http://research.bmn.com/medline/sear...=MDLN.21475748

18 Journal Article 22326944 Doherty, M., Smith, P.M., Davison, R.C., Hughes, M.G. Caffeine is ergogenic after supplementation of oral creatine monohydrate. Medicine and Science in Sports and Exercise 34 (11) 1785-1792 2002

19 Journal Article 98133794 Kreider, R.B., Ferreira, M., Wilson, M., Grindstaff, P., Plisk, S., Reinardy, J., Cantler, E., Almada, A.L. Effects of creatine supplementation on body composition, strength, and sprint performance. Medicine and Science in Sports and Exercise 30 (1) 73-82 1998

20 Journal Article 97333624 Terrillion, K.A., Kolkhorst, F.W., Dolgener, F.A., Joslyn, S.J. The effect of creatine supplementation on two 700-m maximal running bouts. International Journal of Sport Nutrition 7 (2) 138-143 1997

21 Journal Article 21548371 Bemben, M.G., Tuttle, T.D., Bemben, D.A., Knehans, A.W. Effects of creatine supplementation on isometric force-time curve characteristics. Medicine and Science in Sports and Exercise 33 (11) 1876-1881 2001 Neuromuscular Research Lab, Department of Health and Sport Sciences, University of Oklahoma, Norman, OK 73019, USA. mgbemben@ou.edu

22 Journal Article 99290801 Urbanski, R.L., Vincent, W.J., Yaspelkis, B.B. Creatine supplementation differentially affects maximal isometric strength and time to fatigue in large and small muscle groups. International Journal of Sport Nutrition 9 (2) 136-145 1999

23 Journal Article 98385956 McNaughton, L.R., Dalton, B., Tarr, J. The effects of creatine supplementation on high-intensity exercise performance in elite performers. Eur J Appl Physiol Occup Physiol 78 (3) 236-240 1998

24 Journal Article 22389286 Mayhew, D.L., Mayhew, J.L., Ware, J.S. Effects of long-term creatine supplementation on liver and kidney functions in American college football players. International Journal of Sport Nutrition and Exercise Metabolism 12 (4) 453-460 2002

25 Journal Article 98071150 Grindstaff, P.D., Kreider, R., Bishop, R., Wilson, M., Wood, L., Alexander, C., Almada, A. Effects of creatine supplementation on repetitive sprint performance and body composition in competitive swimmers. International Journal of Sport Nutrition 7 (4) 330-346 1997

26 Journal Article 21465110 Bemben, M.G., Bemben, D.A., Loftiss, D.D., Knehans, A.W. Creatine supplementation during resistance training in college football athletes. Medicine and Science in Sports and Exercise 33 (10) 1667-1673 2001

27 Journal Article 20484234 Hamilton, K.L., Meyers, M.C., Skelly, W.A., Marley, R.J. Oral creatine supplementation and upper extremity anaerobic response in females. International Journal of Sport Nutrition and Exercise Metabolism 10 (3) 277-89 2000

28 Journal Article 99100531 Juhn, M.S., Tarnopolsky, M. Oral creatine supplementation and athletic performance: a critical review. Clinical Journal of Sport Medicine : Official Journal of the Canadian Academy of Sport Medicine 8 (4) 286-297 1998

29 Journal Article 21565021 Burke, D.G., Smith_Palmer, T., Holt, L.E., Head, B., Chilibeck, P.D. The effect of 7 days of creatine supplementation on 24-hour urinary creatine excretion. J Strength Cond Res 15 (1) 59-62 2001

30 Journal Article 21023281 Op__t_Eijnde, B., Urso, B., Richter, E.A., Greenhaff, P.L., Hespel, P. Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization. Diabetes 50 (1) 18-23 2001

31 Journal Article 21637953 Lawler, J.M., Barnes, W.S., Wu, G., Song, W., Demaree, S. Direct antioxidant properties of creatine. Biochemical and Biophysical Research Communications 290 (1) 47-52 2002

32 Journal Article 22635681 Vierck, J.L., Icenoggle, D.L., Bucci, L., Dodson, M.V. The effects of ergogenic compounds on myogenic satellite cells. Medicine and Science in Sports and Exercise 35 (5) 769-776 2003

33 Journal Article 97359638 Volek, J.S., Kraemer, W.J., Bush, J.A., Boetes, M., Incledon, T., Clark, K.L., Lynch, J.M. Creatine supplementation enhances muscular performance during high-intensity resistance exercise. Journal of the American Dietetic Association 97 (7) 765-770 1997

34 Journal Article 20380511 Casey, A., Greenhaff, P.L. Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? The American Journal of Clinical Nutrition 72 (2 Suppl) 607S-617S 2000

35 Journal Article 99334815 Francaux, M., Poortmans, J.R., Effects of training and creatine supplement on muscle strength and body mass. Eur J Appl Physiol Occup Physiol 80 (2) 165-168 1999

36 Journal Article 99026909 Aaserud, R., Gramvik, P., Olsen, S.R., Jensen, J. Creatine supplementation delays onset of fatigue during repeated bouts of sprint running. Scandinavian Journal of Medicine & Science in Sports 8 (5 Pt 1) 247-251 1998

37 Journal Article 22811950 Lehmkuhl, M., Malone, M., Justice, B., Trone, G., Pistilli, E., Vinci, D., Haff, E.E., Lon_Kilgore, J., Gregory_Haff, G. The effects of 8 weeks of creatine monohydrate and glutamine supplementation on body composition and performance measures. J Strength Cond Res 17 (3) 425-438 2003

38 Journal Article 99053582 Vandebuerie, F., Vanden_Eynde, B., Vandenberghe, K., Hespel, P. Effect of creatine loading on endurance capacity and sprint power in cyclists. International Journal of Sports Medicine 19 (7) 490-495 1998

39 Journal Article 22587393 Tarnopolsky, M., Parise, G., Fu, M.H., Brose, A., Parshad, A., Speer, O., Wallimann, T. Acute and moderate-term creatine monohydrate supplementation does not affect creatine transporter mRNA or protein content in either young or elderly humans. Molecular and Cellular Biochemistry 244 (1-2) 159-166 2003

40 Journal Article 22373781 Dempsey, R.L., Mazzone, M.F., Meurer, L.N. Does oral creatine supplementation improve strength? A meta-analysis. The Journal of Family Practice 51 (11) 945-951 2002

41 Journal Article 97333142 Jacobs, I., Bleue, S., Goodman, J. Creatine ingestion increases anaerobic capacity and maximum accumulated oxygen deficit. Canadian Journal of Applied Physiology 22 (3) 231-243 1997

42 Journal Article 97087493 Mujika, I., Chatard, J.C., Lacoste, L., Barale, F., Geyssant, A. Creatine supplementation does not improve sprint performance in competitive swimmers. Medicine and Science in Sports and Exercise 28 (11) 1435-41 1996

43 Journal Article 96318457 Febbraio, M.A., Flanagan, T.R., Snow, R.J., Zhao, S., Carey, M.F. Effect of creatine supplementation on intramuscular TCr, metabolism and performance during intermittent, supramaximal exercise in humans. Acta Physiologica Scandinavica 155 (4) 387-395 1995

44 Journal Article 21988919 Cox, G., Mujika, I., Tumilty, D., Burke, L. Acute creatine supplementation and performance during a field test simulating match play in elite female soccer players. International Journal of Sport Nutrition and Exercise Metabolism 12 (1) 33-46 2002

45 Journal Article 21150426 Op__t_Eijnde, B., Hespel, P. Short-term creatine supplementation does not alter the hormonal response to resistance training. Medicine and Science in Sports and Exercise 33 (3) 449-453 2001

46 Journal Article 22038697 Yquel, R.J., Arsac, L.M., Thiaudiere, E., Canioni, P., Manier, G. Effect of creatine supplementation on phosphocreatine resynthesis, inorganic phosphate accumulation and pH during intermittent maximal exercise. Journal of Sports Sciences 20 (5) 427-437 2002

47 Journal Article 21400722 Parise, G., Mihic, S., MacLennan, D., Yarasheski, K.E., Tarnopolsky, M.A. Effects of acute creatine monohydrate supplementation on leucine kinetics and mixed-muscle protein synthesis. Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology 91 (3) 1041-1047 2001

48 Journal Article 21342398 Jowko, E., Ostaszewski, P., Jank, M., Sacharuk, J., Zieniewicz, A., Wilczak, J., Nissen, S. Creatine and beta-hydroxy-beta-methylbutyrate (HMB) additively increase lean body mass and muscle strength during a weight-training program. Nutrition (Burbank, Los Angeles County, Calif.) 17 (7-8) 558-566

49 Journal Article 21126521 Schilling, B.K., Stone, M.H., Utter, A., Kearney, J.T., Johnson, M., Coglianese, R., Smith, L., O_Bryant, H.S., Fry, A.C., Starks, M., Keith, R., Stone, M.E. Creatine supplementation and health variables: a retrospective study. Medicine and Science in Sports and Exercise 33 (2) 183-188 2001

50 Journal Article 22811951 Biwer, C.J., Jensen, R.L., Schmidt, W.D., Watts, P.B. The effect of creatine on treadmill running with high-intensity intervals. J Strength Cond Res 17 (3) 439-445 2003 Capital University, Columbus, Ohio 43209.

51 Journal Article 22311480 Warber, J.P., Tharion, W.J., Patton, J.F., Champagne, C.M., Mitotti, P., Lieberman, H.R. The effect of creatine monohydrate supplementation on obstacle course and multiple bench press performance. J Strength Cond Res 16 (4) 500-508 2002

52 Journal Article 22088719 Oopik, V., Paasuke, M., Timpmann, S., Medijainen, L., Ereline, J., Gapejeva, J. Effects of creatine supplementation during recovery from rapid body mass reduction on metabolism and muscle performance capacity in well-trained wrestlers. The Journal of Sport Medicine and Physical Fitness 42 (3) 330-339 2002

53 Journal Article 97197136 Odland, L.M., MacDougall, J.D., Tarnopolsky, M.A., Elorriaga, A., Borgmann, A. Effect of oral creatine supplementation on muscle [PCr] and short-term maximum power output. Medicine and Science in Sports and Exercise 29 (2) 216-219 1997

54 Journal Article 21592773 Arciero, P.J., Hannibal, N.S., Nindl, B.C., Gentile, C.L., Hamed, J., Vukovich, M.D. Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow. Metabolism: Clinical and Experimental 50 (12) 1429-1434 2001

55 Journal Article 21486770 Hespel, P., Op_t_Eijnde, B., Van_Leemputte, M., Urso, B., Greenhaff, P.L., Labarque, V., Dymarkowski, S., Van_Hecke, P., Richter, E.A. Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol 536 (Pt 2) 625-633 2001

56 Journal Article 21218098 Finn, J.P., Ebert, T.R., Withers, R.T., Carey, M.F., Mackay, M., Phillips, J.W., Febbraio, M.A. Effect of creatine supplementation on metabolism and performance in humans during intermittent sprint cycling. European Journal of Applied Physiology and Occupational Physiology 84 (3) 238-243 2001

57 Journal Article 99406507 Leenders, N.M., Lamb, D.R., Nelson, T.E. Creatine supplementation and swimming performance. International Journal of Sport Nutrition 9 (3) 251-262 1999

58 Journal Article 97448067 Schneider, D.A., McDonough, P.J., Fadel, P.J., Berwick, J.P. Creatine supplementation and the total work performed during 15-s and 1-min bouts of maximal cycling. Australian Journal of Science and Medicine in Sport 29 (3) 65-68 1997

59 Journal Article 97442229 Bosco, C., Tihanyi, J., Pucspk, J., Kovacs, I., Gabossy, A., Colli, R., Pulvirenti, G., Tranquilli, C., Foti, C., Viru, M., Viru, A. Effect of oral creatine supplementation on jumping and running performance. International Journal of Sports Medicine 18 (5) 369-372 1997

60 Journal Article 20484232 Burke, D.G., Silver, S., Holt, L.E., Smith_Palmer, T., Culligan, C.J., Chilibeck, P.D. The effect of continuous low dose creatine supplementation on force, power, and total work. International Journal of Sport Nutrition and Exercise Metabolism 10 (3) 235-244 2000

61 Journal Article 20193275 Becque, M.D., Lochmann, J.D., Melrose, D.R. Effects of oral creatine supplementation on muscular strength and body composition. Medicine and Science in Sports and Exercise 32 (3) 654-658 2000

62 Journal Article 99322079 Miura, A., Kino, F., Kajitani, S., Sato, H., Fukuba, Y. The effect of oral creatine supplementation on the curvature constant parameter of the power-duration curve for cycle ergometry in humans. Japanese Journal of Physiology 49 (2) 169-174 1999

63 Journal Article 98239680 Snow, R.J., McKenna, M.J., Selig, S.E., Kemp, J., Stathis, C.G., Zhao, S. Effect of creatine supplementation on sprint exercise performance and muscle metabolism. Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology 84 (5) 1667-1673 1998

64 Journal Article 98067374 Poortmans, J.R., Auquier, H., Renaut, V., Durussel, A., Saugy, M., Brisson, G.R. Effect of short-term creatine supplementation on renal responses in men. Eur J Appl Physiol Occup Physiol 76 (6) 566-567 1997

65 Journal Article 96330166 Casey, A., Constantin_Teodosiu, D., Howell, S., Hultman, E., Greenhaff, P.L. Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. The American Journal of Physiology 271 (1 Pt 1) E31-E37 1996

66 Journal Article 96170646 Dawson, B., Cutler, M., Moody, A., Lawrence, S., Goodman, C., Randall, N. Effects of oral creatine loading on single and repeated maximal short sprints. Australian Journal of Science and Medicine in Sport 27 (3) 56-61 1995

67 Journal Article 21830495 Syrotuik, D.G., Game, A.B., Gillies, E.M., Bell, G.J. Effects of creatine monohydrate supplementation during combined strength and high intensity rowing training on performance. Canadian Journal of Applied Physiology 26 (6) 527-542 2001

68 Journal Article 21583672 Stevenson, S.W., Dudley, G.A., Creatine loading, resistance exercise performance, and muscle mechanics. J Strength Cond Res 15 (4) 413-419 2001

69 Journal Article 20522931 Nelson, A.G., Day, R., Glickman_Weiss, E.L., Hegsted, M., Kokkonen, J., Sampson, B. Creatine supplementation alters the response to a graded cycle ergometer test. European Journal of Applied Physiology and Occupational Physiology 83 (1) 89-94 2000

70 Journal Article 20155812 Rico_Sanz, J., Mendez_Marco, M.T. Creatine enhances oxygen uptake and performance during alternating intensity exercise. Medicine and Science in Sports and Exercise 32 (2) 379-385 2000

71 Journal Article 20155801 Mihic, S., MacDonald, J.R., McKenzie, S., Tarnopolsky, M.A. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women. Medicine and Science in Sports and Exercise 32 (2) 291-296 2000

72 Journal Article 22869137 Brilla, L.R., Giroux, M.S., Taylor, A., Knutzen, K.M. Magnesium-creatine supplementation effects on body water. Metabolism: Clinical and Experimental 52 (9) 1136-1140 2003

73 Journal Article 22811952 Delecluse, C., Diels, R., Goris, M. Effect of creatine supplementation on intermittent sprint running performance in highly trained athletes. J Strength Cond Res 17 (3) 446-454 2003

74 Journal Article 22546865 Preen, D., Dawson, B., Goodman, C., Beilby, J., Ching, S. Creatine supplementation: a comparison of loading and maintenance protocols on creatine uptake by human skeletal muscle. International Journal of Sport Nutrition and Exercise Metabolism 13 (1) 112-116 2003

75 Journal Article 22470013 Watsford, M.L., Murphy, A.J., Spinks, W.L., Walshe, A.D. Creatine supplementation and its effect on musculotendinous stiffness and performance. J Strength Cond Res 17 (1) 26-33 2003

76 Journal Article 22409023 Persky, A.M., Muller, M., Derendorf, H., Grant, M., Brazeau, G.A., Hochhaus, G. Single- and multiple-dose pharmacokinetics of oral creatine. Journal of Clinical Pharmacology 43 (1) 29-37 2003

77 Journal Article 99199346 van_Leemputte, M., Vandenberghe, K., Hespel, P. Shortening of muscle relaxation time after creatine loading. Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology 86 (3) 840-844 1999

78 Journal Article 21565018 Green, J.M., McLester, J.R., Smith, J.E., Mansfield, E.R. The effects of creatine supplementation on repeated upper- and lower-body Wingate performance. J Strength Cond Res 15 (1) 36-41 2001

79 Journal Article 21338893 Volek, J.S., Mazzetti, S.A., Farquhar, W.B., Barnes, B.R., Gomez, A.L., Kraemer, W.J. Physiological responses to short-term exercise in the heat after creatine loading. Medicine and Science in Sports and Exercise 33 (7) 1101-1108 2001

80 Journal Article 20407990 Robinson, T.M., Sewell, D.A., Casey, A., Steenge, G., Greenhaff, P.L. Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function. British Journal of Sports Medicine 34 (4) 284-8 2000

81 Journal Article 20109279 Stout, J., Eckerson, J., Ebersole, K., Moore, G., Perry, S., Housh, T., Bull, A., Cramer, J., Batheja, A. Effect of creatine loading on neuromuscular fatigue threshold. Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology 88 (1) 109-112 2000

82 Journal Article 20078587 Kamber, M., Koster, M., Kreis, R., Walker, G., Boesch, C., Hoppeler, H. Creatine supplementation--part I: performance, clinical chemistry, and muscle volume. Medicine and Science in Sports and Exercise 31 (12) 1763-1769 1999

83 Journal Article 22811949 Selsby, J.T., Beckett, K.D., Kern, M., Devor, S.T. Swim Performance Following Creatine Supplementation in Division III Athletes. J Strength Cond Res 17 (3) 421-424 2003

84 Journal Article 98220835 Smith, J.C., Stephens, D.P., Hall, E.L., Jackson, A.W., Earnest, C.P. Effect of oral creatine ingestion on parameters of the work rate-time relationship and time to exhaustion in high-intensity cycling. Eur J Appl Physiol Occup Physiol 77 (4) 360-365 1998

85 Journal Article 21190666 Schedel, J.M., Tanaka, H., Kiyonaga, A., Shindo, M., Schutz, Y. Acute creatine loading enhances human growth hormone secretion. The Journal of Sport Medicine and Physical Fitness 40 (4) 336-342 2000

86 Journal Article 22587384 Kurosawa, Y., Hamaoka, T., Katsumura, T., Kuwamori, M., Kimura, N., Sako, T., Chance, B. Creatine supplementation enhances anaerobic ATP synthesis during a single 10 sec maximal handgrip exercise. Molecular and Cellular Biochemistry 244 (1-2) 105-112 2003
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Creatine Supplementation
Beth Lulinski, M.S., R.D.

Creatine is marketed as "nature's muscle builder" and "the most legitimate sports supplement around." Professional and amateur athletes alike are gobbling up this alleged ergogenic aid, hoping to increase their strength and performance. Creatine supplementation is claimed to increase muscle power by playing a role in the transfer of energy to help the muscle contract. Supplement labels state that "creatine is converted to phosphocreatine, which is important for short energy bursts such as sprinting and weight lifting" and that "depletion of phosphocreatine can result in muscle fatigue and fading muscle power." Claims are also made that supplementation increases muscle body mass.

Health-food stores sell creatine supplements in capsule, chewable, and powdered form, the most popular being the powder. One teaspoon of powder contains 5 grams (g) of creatine monohydrate. The recommended daily dose is 1-2 teaspoons dissolved in 8 ounces of water or sweetened beverage. Manufacturers and distributors suggest a five- to seven-day loading phase with intake of 10-20 g (2-4 scoops) daily to fill up the muscle. The maintenance phase of 5-10 g/day is recommended before and/or immediately following a workout. This protocol is claimed to increase creatine muscle stores by 20-50%.
Role In Muscle Contraction

To meet the demands of a high-intensity exercise, such as a sprint, muscles derive their energy from a series of reactions involving adenosine triphosphate (ATP), phosphocreatine (PCr), adenosine diphosphate (ADP), and creatine. ATP, the amount of which is relatively constant, provides energy when it releases a phosphate molecule and becomes ADP. ATP is regenerated when PCr donates a phosphate molecule that combines with ADP. Stored PCr can fuel the first 4-5 seconds of a sprint, but another fuel source must provide the energy to sustain the activity. Creatine supplements increase the storage of PCr, thus making more ATP available to fuel the working muscles and enable them to work harder before becoming fatigued [1].
Sources

The body's pool of creatine can be replenished either from food (or supplements) or through synthesis from precursor amino acids. Dietary sources include beef, tuna, cod, salmon, herring, and pork [2]. The normal dietary intake of creatine is 1-2 g/day, although vegetarians may consume less [3,4]. Dietary creatine is absorbed from the intestines into the bloodstream. If the dietary supply is limited, creatine can be synthesized from the body stores of the amino acids glycine, arginine, and methionine. The kidneys use glycine and arginine to make guanidinoacetate, which the liver methylates to form creatine [1], which is transported to the muscle cells for storage. It is also stored in the kidneys, sperm cells, and brain tissue [5].

The maximum amount of creatine the body can store is about 0.3 gram per kilogram of body weight [6]. The creatine content of skeletal (voluntary) muscles averages 125 millimoles per kilogram of dry matter (mmol/kg/dm) and ranges from about 60 to 160 mmol/kg/dm. Approximately 60% of muscle creatine is in the form of PCr. Human muscle seems to have an upper limit of creatine storage of 150 to 160 mmol/kg/dm. Athletes with high creatine stores don't appear to benefit from supplementation, whereas individuals with the lowest levels, such as vegetarians, have the most pronounced increases following supplementation. Without supplementation, the body can replenish muscle creatine at the rate of about 2 g/day [7].

Although creatine is a natural component of food, the amount of food required to supersaturate the muscle with PCr may not be feasible. For example, it could require 22 pounds of meat daily [8]. If creatine monohydrate is proven to be a safe and effective ergogenic aid, creatine supplementation may be the simplest way to increasing muscle stores. It may be beneficial to avoid caffeine if taking creatine supplements. One study showed that caffeine diminished strength gains seen with creatine use [9].
Evidence Supporting Use

Several studies support the use of creatine supplementation for enhancing activities that require short periods of high-intensity power and strength. These include weightlifting, sprinting, and rowing.

* One study demonstrated that daily supplementation with 5 g of creatine monohydrate increased the intracellular creatine and PCr content of quadriceps muscle in 17 human subjects. Those with the lowest initial total creatine content had the greatest increase. In addition, exercise enhanced creatine uptake in muscle. No adverse effects were reported [5].
* Another study found that one week of creatine supplementation at 25 g/day enhanced muscular performance during repeated sets of bench press and jump squat exercise. Creatine supplementation appeared to allow the subjects to complete their workouts at a higher intensity. The researchers concluded that, over time, working at higher intensities may provide a more intense training stimulus and improved muscular adaptations [10].
* Another study demonstrated that females receiving 4 days of high-dose creatine intake (20 g/day) followed by low-dose creatine intake (5 g/day) during 10 weeks of resistance training (3hours/week) increased muscle PCr concentrations by 6%. Also, maximal strength of the muscle groups trained increased by 20-25%, maximal intermittent exercise capacity of the arm flexors increased by 10-25% and fat-free mass increased by 60% [11].
* A double-blind study provided 20 g/day of creatine monohydrate for 5 days to qualified sprinters and jumpers who performed 45 seconds of continuous jumping and 60 seconds of continuous treadmill running. Supplementation enhanced performance in the jumping test by 7% for the first 15 seconds and 12% for the next 15 seconds, but there was no difference for the final 15 seconds. There was a 13% improvement in the time of intensive running to exhaustion [12].
* Another double-blind study supplemented with 18.75 g/day of creatine monohydrate for 5 days prior to high-intensity intermittent work to exhaustion, and then 2.25 g/day during testing. The workouts consisted of cycling to exhaustion using several protocols: (a) nonstop, (b) 60 seconds work/120 seconds rest, (c) 20 seconds work/40 seconds rest, and (d) 10 seconds work/20 seconds rest. Creatine supplementation significantly increased the total work time for all four protocols [13].
* Another study tested male subjects performing two bouts of 30 second isokinetic cycling before and after ingesting 20 g creatine monohydrate daily for 5 days. Work production improved about 4%. Cumulative increases in both peak and total work production over the two exercise bouts were positively correlated with the increase in muscle creatine [14].
* A 12-week placebo-controlled study of 19 weightlifters in their mid-twenties found that the creatine group could lift more weight and had greater increases in fat-free mass and muscle-fiber size than did the placebo group. The researchers thought that the creatine let the athletes who used it train harder [15].
* Three additional studies suggest that creatine supplementation may not be beneficial for running velocity, sprint swimming performance, or a maximal cycling effort [7]. Short bouts of repeated anaerobic activity have shown some potential benefits with creatine supplementation use in a laboratory setting. However, creatine supplementation has not been shown to enhance single-event performance such as stationary cycling [16-19]. Taken together, these studies do not support creatine supplementation to enhance aerobic activities such as distance running.

Other areas of research include therapeutic uses of creatine to help patients with muscle wasting caused by disease states such as muscular dystrophy and amyotrophic lateral sclerosis (ALS). Small-scale preliminary studies show some gains in strength may be possible for these patients, which could improve their quality of life. One study of 81 patients with various neurologic diseases found that giving 10 g/day of creatine for five days, followed by 5 grams for another week, increases their muscle strength by about 10% [20]. Large-scale studies should be done before recommendations are made to such patients.
Adverse Effects

Creatine supplementation often causes weight gain that can be mistaken for increase in muscle mass. Increasing intracellular creatine may cause an osmotic influx of water into the cell because creatine is an osmotically active substance [10]. It is possible that the weight gained is water retention and not increased muscle. The retention of water may be connected to reports of muscle cramps, dehydration, and heat intolerance when taking creatine supplements. It would be prudent to encourage proper hydration for creatine users. Further research is needed to investigate these and other possible side effects.

Creatine is classified as a "dietary supplement" under the 1994 Dietary Supplement Health and Education Act and is available without a prescription. Creatine is not subjected to FDA testing, and the purity and hygienic condition of commercial creatine products may be questionable [21]. A 1998 FDA report lists 32 adverse creatine-associated events that had been reported to FDA. These include seizure, vomiting, diarrhea, anxiety, myopathy, cardiac arrhythmia, deep vein thromboses and death. However, there is no certainty that a reported adverse event can be attributed to a particular product [22]. A recent survey of 28 male baseball players and 24 male football players, ages 18 to 23, found that 16 (31%) experienced diarrhea, 13 (25%) experienced muscle cramps, 7 (13%) reported unwanted weight gain, 7 (13%) reported dehydration, and 12 reported various other adverse effects [23].


* Jenkins, MA. Creatine supplementation in athletes: Review
* Creatine is the object of intensive research. To keep current, use the links below to visit the abstracts on PubMed and click on "Related Articles" when you arrive.

References

1. Murray RK and others. Harper's Biochemistry, 24th Edition. Stamford, CT: Appleton & Lange, 1996.
2. Sahelian R, Tutle D. Creatine: Nature's Muscle Builder. Garden City, NY: Avery Publishing Group, 1997.
3. Toler S. Creatine is an ergogen for anaerobic exercise. Nutrition Reviews 55:21-25, 1997.
4. Maughan R. Creatine supplementation and exercise performance. International Journal of Sport Nutrition 5:94-101, 1995.
5. Harris RC, Soderlund K, Hultman E. Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clinical Science 83:367-374, 1992.
6. Haff GG, Potteiger JA. Creatine supplementation for the strength/power athlete. Strength and Conditioning 19(6):72-74, 1997.
7. Coleman E. Creatine monohydrate: a sprint performance enhancer? HCRC Web site.
8. Modica P. Creatine supplements show some sports benefit. Medical Tribune News Service. July 10, 1997.
9. Vandenberghe K and others. Caffeine counteracts the ergogenic action of muscle creatine loading. Journal of Applied Physiology 80:452-457, 1996.
10. Volek JS and others. Creatine supplementation enhances muscular performance during high-intensity resistance exercise. Journal of American Dietetic Association 97:765-770, 1997.
11. Vandenberghe K and others. Long-term creatine intake is beneficial to muscle performance during resistance training. Journal of Applied Physiology 83:2055-2063, 1997.
12. Bosco C and others. Effect of oral creatine supplementation on jumping and running performance. International Journal of Sports Medicine 18:369-372, 1997.
13. Prevost MC, Nelson AG, Morris GS. Creatine supplementation enhances intermittent work performance. Research Quarterly for Exercise and Sport 68:233-240, 1997.
14. Casey A and others. Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. American Journal of Physiology 271(1):E31-E37, 1996.
15. Volek JS and others. Performance and muscle fiber adaptations to creatine supplementation and heavy resistance training. Medicine and Science in Sports and Exercise 31:1147-1156, 1999.
16. Dawson B and others. Effects of oral creatine loading on single and repeated maximal short sprints. Australian Journal of Science and Medicine in Sport 27(3):56-61, 1995.
17. Cooke WH, Grandjean PW, Barnes WS. Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry. Journal of Applied Physiology 78:670-673, 1995.
18. Odland LM and others. Effect of oral creatine supplementation on muscle [Pcr] and short-term maximum power output. Medicine and Science in Sports and Exercise 29:216-219, 1997.
19. Snow RJ and others. Effect of creatine supplementation on sprint exercise performance and muscle metabolism Journal of Applied Physiology 84:1667-1673, 1998.
20. Tarnopolsky M. Creatine monohydrate increases strength in patients with neuromuscular diseases. Neurology 52:854-857, 1999.
21. Sorgen C. Creatine supplementation: The quest for power performance. Today's Dietitian (1)3:26-29, 1999.
22. FDA Special Nutritionals Adverse Event Monitoring System. Accessed June 7, 1999.
23. Juhn MS and others. Oral creatine supplementation in male collegiate athletes: A survey of dosing habits and side effects. Journal of the American Dietetic Association 99:593-594, 1999.

good stuff !!! thanks for the info bro

Great read man!

Thanks Allstar for the studies!

Because the text is so large, I'd edit it to the hypothesis, abstract and conclusive data. Also remove the references; keep them on hand if Tim, IS, Braaq, etc. are interested in responsibility. Also, add subtitles to title each topic...that'd be great bro. Bookmarked.