• Creatine Monohydrate
Creatine is a naturally occurring substance that plays an important role in the production of energy in the body. The body converts it to phosphocreatine, a form of stored energy used by muscles.
Although the evidence for creatine is not definitive, it has the most evidence behind it among all the sports supplements. Numerous small double-blind studies suggest that it can increase athletic performance in sports that involve intense but short bursts of activity.
The theory behind its use is that supplemental creatine can build up a reserve of phosphocreatine in the muscles to help them perform on demand. Supplemental creatine may also help the body make new phosphocreatine faster when it has been used up by intense activity.
Although some creatine exists in the daily diet, it is not an essential nutrient because your body can make it from the amino acids L-arginine
Meat (including chicken and fish) is the most important dietary source of creatine and its amino acid building blocks. For this reason, vegetarian athletes may potentially benefit most from creatine supplementation.
For bodybuilding and exercise enhancement, a typical dosage schedule starts with a "loading dose" of 15 to 30 g daily (divided into 2 or 3 separate doses) for 3 to 4 days, followed by 2 to 5 g daily. Some authorities recommend skipping the loading dose. (By comparison, we typically get only about 1 g of creatine in the daily diet.)
Creatine's ability to enter muscle cells can be increased by combining it with glucose, fructose, or other simple carbohydrates; 1,2
Caffeine may block the effects of creatine.
Creatine is one of the best-selling and best documented supplements for enhancing athletic performance
Preliminary evidence suggests that creatine supplements may be able to reduce levels of
Creatine supplements might also help counter the loss of muscle strength that occurs when a limb is immobilized, such as following
Studies, including small, double-blind trials, inconsistently suggest that creatine might be helpful for reducing fatigue and increasing strength in various illnesses where muscle weakness occurs, including
One study claimed to find evidence that creatine supplements can reduce levels of blood sugar.
Evidence from animal and open human trials suggested that creatine improved strength and slowed the progression of
Creatine has also shown some promise for
One study failed to find creatine helpful for maintaining muscle mass during treatment for
What Is the Scientific Evidence for Creatine?
For example, a double-blind study investigated creatine and swimming performance in 18 men and 14 women.
Interestingly, none of the women enrolled in the study showed any improvement with the creatine supplement. The authors of this study noted that women normally have more creatine in their muscle tissue than men do, so perhaps creatine supplementation (at least at this level) is not of benefit to women, as it appears to be for men. Further research is needed to fully understand this gender difference in response to creatine.
In another double-blind study, 16 physical education students exercised 10 times for 6 seconds on a stationary cycle, alternating with a 30-second rest period.
Isometric exercise capacity (pushing against a fixed resistance) also may improve with creatine, according to some, but not all studies.
In addition, two double-blind, placebo-controlled studies, each lasting 28 days, provide some evidence that creatine and creatine plus HMB (beta hydroxymethyl butyrate) can increase lean muscle and bone mass.
A 56-day, double-blind, placebo-controlled study of 34 men and women found that creatine supplementation can
Congestive Heart Failure
Easy fatigability is one unpleasant symptom of
A double-blind study examined 17 men with congestive heart failure who were given 20 g of creatine daily for 10 days.
These results are promising, but further study is needed.
Creatine appears to be relatively safe. 45
Dividing the dose may help avoid gastrointestinal side effects (diarrhea, stomach upset, and belching). In one study of 59 male soccer players, two separate 5 g doses was associated with less diarrhea than a single 10 g dose.
However, there are some potential concerns with creatine. Because it is metabolized by the kidneys, fears have been expressed that creatine supplements could cause kidney injury, and there are two worrisome case reports.
Another concern revolves around the fact that creatine is metabolized in the body to the toxic substance formaldehyde.
It has also been suggested that use of oral creatine would increase urine levels of the carcinogen N-nitrososarcosine, but this does not seem to be the case.
As with all supplements taken in very high doses, it is important to purchase a high-quality form of creatine, as contaminants present even in very low concentrations could conceivably build up and cause problems.
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46. Kreider R, Rasmussen C, Melton C, et al. Long-term creatine supplementation does not adversely affect clinical markers of health. Poster presented at: American College of Sports Medicine 2000 Annual Scientific Meeting; May 31-June 3, 2000; Indianapolis, IN.
51. Mihic S, MacDonald JR, McKenzie S, et al. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women. Med Sci Sports Exerc. 2000;32:291-296.
54. Hespel P, Eijnde BO, Van Leemputte M, et al. Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol. 2001;536:625-633.
56. Vorgerd M, Zange J, Kley R, et al. Effect of high-dose creatine therapy on symptoms of exercise intolerance in McArdle disease: Double-blind, placebo-controlled crossover study. Arch Neurol. 2002;59:97-101.
60. Roy BD, Bourgeois JM, Mahoney DJ, et al. Dietary supplementation with creatine monohydrate prevents corticosteroid-induced attenuation of growth in young rats. Can J Physiol Pharmacol. 2002;80:1008-1014.
62. Tyler TF, Nicholas SJ, Hershman EB, et al. The effect of creatine supplementation on strength recovery after anterior cruciate ligament (ACL) reconstruction: a randomized, placebo-controlled, double-blind trial. Am J Sports Med. 2004;32:383-388.
64. Tarnopolsky M, Mahoney D, Thompson T, et al. Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1. Muscle Nerve. 2004;29:51-58.
77. Kendall RW, Jacquemin G, Frost R, et al. Creatine supplementation for weak muscles in persons with chronic tetraplegia: a randomized double-blind placebo-controlled crossover trial. J Spinal Cord Med. 2005;28:208-213
78. McMorris T, Harris RC, Swain J, et al. Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol. Psychopharmacology (Berl). 2006 Jan 17. [Epub ahead of print]
79. Rae C, Digney AL, McEwan SR, et al. Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial. Proc R Soc Biol Sci. 2003;270:2147-2150.
80. Norman K, Stubler D, Baier P, et al. Effects of creatine supplementation on nutritional status, muscle function and quality of life in patients with colorectal cancer-A double blind randomised controlled trial. Clin Nutr. 2006 May 12. [Epub ahead of print]
82. Theodorou AS, Havenetidis K, Zanker CL, et al. Effects of Acute Creatine Loading With or Without Carbohydrate on Repeated Bouts of Maximal Swimming in High-Performance Swimmers. J Strength Cond Res. 2005;19:265-269.
86. Eckerson JM, Stout JR, Moore GA, et al. Effect of Creatine Phosphate Supplementation on Anaerobic Working Capacity and Body Weight After Two and Six Days of Loading in Men and Women. J Strength Cond Res. 2005;19:756-763.
87. Astorino, T.A., A.C. Marrocco, S.M. Gross, D.L. Johnson, C.M. Brazil, M.E. Icenhower, and R.J. Kneessi. Is running performance enhanced with creatine serum ingestion? J. Strength Cond. Res. 2005;19:730-734.
91. Derave W, Vanden Eede E, Hespel P, et al. Oral creatine supplementation in humans does not elevate urinary excretion of the carcinogen N-nitrososarcosine. Nutrition. 2006 Jan 12. [Epub ahead of print]
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97. Chung YL, Alexanderson H, Pipitone N, et al. Creatine supplements in patients with idiopathic inflammatory myopathies who are clinically weak after conventional pharmacologic treatment: Six-month, double-blind, randomized, placebo-controlled trial. Arthritis Rheum. 2007 Apr 30. [Epub ahead of print]
99. Wright GA, Grandjean PW, Pascoe DD. The effects of creatine loading on thermoregulation and intermittent sprint exercise performance in a hot humid environment. J Strength Cond Res. 2007;21:655-660.
100. Cramer JT, Stout JR, Culbertson JY, et al. Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function. J Strength Cond Res. 2007;21:668-677.
101. Faager G, Soderlund K, Skold CM, et al. Creatine supplementation and physical training in patients with COPD: a double blind, placebo-controlled study. Int J Chron Obstruct Pulmon Dis. 2006;1:445-453.
102. Gualano B, Ugrinowitsch C, Novaes RB, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol. 2008 Jan 11.
Last reviewed April 2009 by EBSCO CAM Review Board
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