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Creatine Monohydrate
Description:
Creatine (creatine monohydrate) is a colorless, crystalline substance used in muscle tissue for the production of phosphocreatine, an important factor in the formation of adenosine triphosphate (ATP), the source of energy for muscle contraction and many other functions in the body.
Properties & Uses:
Creatine is best for the serious bodybuilder. It helps increase muscle mass, rather than muscle endurance, so it’s not well suited for athletes participating in endurance activities. However, the increase in muscle mass may be due to water retention and not an increase in muscle tissue.
Recommended Dietary Allowances:
Over 40 double-blind or controlled studies have found creatine supplementation (typically 136 mg per pound of body weight per day or 15 to 25 grams per day for five or six days) improves performance of either single or repetitive bouts of short-duration, high-intensity exercise lasting under 30 seconds each.3 4 5 6 7 8 9 Examples of this type of exercise include weightlifting; sprinting by runners, cyclists, or swimmers; and many types of athletic training regimens for speed and power. About 15 studies did not report enhancement by creatine of this type of performance. These have been criticized for their small size and other research design problems, but it is possible that some people, especially elite athletes, are less likely to benefit greatly from creatine supplementation.10
Long-term use of creatine supplementation is typically done using smaller daily amounts (2 to 5 grams per day) after an initial loading period of several days with 20 grams per day. Very little research has been done to investigate the exercise performance effects of long-term creatine supplementation. One study reported that long-term creatine supplementation improved sprint performance.11 Four controlled long-term trials using untrained women,12 trained men,13 or untrained older adults found that creatine improved gains made in strength and lean body mass from weight-training programs.14 15 However, two controlled trials found no advantage of long-term creatine supplementation in weight-training football players
Food Sources:
Creatine is produced naturally in the human liver, pancreas, and kidneys. It is concentrated primarily in muscle tissues, including the heart. Animal proteins, including fish, are the main source of the 1–2 grams per day of dietary creatine most people consume. Supplements in the form of creatine monohydrate are well absorbed and tolerated by the stomach.
Side Effects & Interactions:
Little is known about long-term side effects of creatine, but no consistent toxicity has been reported in studies of creatine supplementation. In a study of side effects of creatine, diarrhea was the most commonly reported adverse effect of creatine supplementation, followed by muscle cramping.18 Some reports showed that kidney, liver, and blood functions were not affected by short-term higher amounts19 20 or long-term lower amounts 21 22 of creatine supplementation in healthy young adults. In a small study of people taking 5–30 grams per day, no change in kidney function appeared after up to five years of supplementation.23 However, interstitial nephritis, a serious kidney condition, developed in an otherwise healthy young man, supplementing with 20 grams of creatine per day.24 Improvement in kidney function followed avoidance of creatine. Details of this case strongly suggest that creatine supplementation triggered this case of kidney disease. Creatine supplementation may also be dangerous for people with existing kidney disease. In one report, a patient with nephrotic syndrome (a kidney disorder) developed glomerulosclerosis (another serious kidney condition) while taking creatine. when the creatine was discontinued, the glomerulosclerosis resolved.25
Muscle cramping after creatine supplementation has been anecdotally reported in three studies.26 27 28
At the time of writing, there were no well-known drug interactions with creatine monohydrate.
References:
1. Greenhaff PL, Bodin K, Soderlund K, et al. Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis. Am J Physiol 1994;266:E725-30.
2. Greenhaff PL. Creatine and its application as an ergogenic aid. Int J Sport Nutr 1995;5:94-101.
3. Mesa JL, Ruiz JR, Gonzalez-Gross MM, et al. Oral creatine supplementation and skeletal muscle metabolism in physical exercise. Sports Med 2002;32:903–44 [review].
4. Watsford ML, Murphy AJ, Spinks WL, Walshe AD. Creatine supplementation and its effect on musculotendinous stiffness and performance. J Strength Cond Res 2003;17:26–33.
5. van Loon LJ, Oosterlaar AM, Hartgens F. Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans. Clin Sci (Lond) 2003;104:153–62.
6. Warber JP, Tharion WJ, Patton JF, et al. The effect of creatine monohydrate supplementation on obstacle course and multiple bench press performance. J Strength Cond Res 2002;16:500–8.
7. Ziegenfuss TN, Rogers M, Lowery L, et al. Effect of creatine loading on anaerobic performance and skeletal muscle volume in NCAA Division I athletes. Nutrition 2002;18:397–402.
8. Cottrell GT, Coast JR, Herb RA. Effect of recovery interval on multiple-bout sprint cycling performance after acute creatine supplementation. J Strength Cond Res 2002;16:109–16.
9. Izquierdo M, Ibanez J, Gonzalez-Badillo JJ, Gorostiaga EM. Effects of creatine supplementation on muscle power, endurance, and sprint performance. Med Sci Sports Exerc 2002;34:332–43.
10. Mesa JL, Ruiz JR, Gonzalez-Gross MM, et al. Oral creatine supplementation and skeletal muscle metabolism in physical exercise. Sports Med 2002;32:903–44 [review].
11. Van Loon LJ, Oosterlaar AM, Hartgens F. Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans. Clin Sci (Lond) 2003;104:153–62.
12. Vandenberghe K, Goris M, Van Hecke P, et al. Long-term creatine intake is beneficial to muscle performance during resistance training. J Appl Physiol 1997;83:2055–63.
13. Becque MD, Lochmann JD, Melrose DR. Effects of oral creatine supplementation on muscular strength and body composition. Med Sci Sports Exerc 2000;32:654–8.
14. Brose A, Parise G, Tarnopolsky MA. Creatine supplementation enhances isometric strength and body composition improvements following strength exercise training in older adults. J Gerontol A Biol Sci Med Sci 2003;58:11–9.
15. Chrusch MJ, Chilibeck PD, Chad KE Creatine supplementation combined with resistance training in older men. Med Sci Sports Exerc 2001;33:2111–7.
16. Stout JR, Eckerson J, Noonan D, et al. The effects of a supplement designed to augment creatine uptake on exercise performance and fat-free mass in football players. Med Sci Sports Exerc 1997;29:S251 [abstract].
17. Wilder N, Gilders R, Hagerman F, Deivert RG. The effects of a 10-week, periodized, off-season resistance-training program and creatine supplementation among collegiate football players. J Strength Cond Res 2002;16:343–52.
18. Juhn MS, O’Kane JW, Vinci DM. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am Diet Assoc 1999;99:593–5.
19. Sewell DA, Robinson TM, Casey A, et al. The effect of acute dietary creatine supplementation upon indices of renal, hepatic and haematological function in human subjects. Proc Nutr Soc 1998;57:17A.
20. Poortmans JR, Auquier H. Renaut V, et al. Effect of short-term creatine supplementation on renal responses in men. Eur J Appl Physiol Occup Physiol 1997;76:566–7.
21. Earnest C, Almada A, Mitchell T. Influence of chronic creatine supplementation on hepatorenal function. FASEB J 1996;10:4588.
22. Almada A, Mitchell T, Earnest C. Impact of chronic creatine supplementation on serum enzyme concentrations. FASEB J 1996;10:4567.
23. Poortmans JR, Francaux M. Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc 1999;31:1108–10.
24. Koshy KM, Griswold E, Schneeberger EE. Interstitial nephritis in a patient taking creatine. N Engl J Med 1999;340:814–5 [letter].
25. Pritchard NR, Kaira PA. Renal dysfunction accompanying oral creatine supplements. Lancet 1998;351:1252–3 [letter].
26. Hultman E, Soderlund K, Timmons J, et al. Muscle creatine loading in man. J Appl Physiol 1996;81:232–7.
27. Vandenberghe K, Goris M, Van Hecke P, et al. Long-term creatine intake is beneficial to muscle performance during resistance training. J Appl Physiol 1997;83:2055–63.
28. Juhn MS, Tarnopolsky M. Potential side effects of oral creatine supplementation: a critical review. Clin J Sport Med 1998;8:298–304 [published erratum appears in Clin J Sport Med 1999;9:62].