What is it?
Creatine (creatine monohydrate) is a colourless, 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.1 2
Creatine monohydrate supplementation increases phosphocreatine levels in muscle in most
people, especially when accompanied by exercise or carbohydrate intake.3
4 However, about 30% of people who take creatine supplements fail to retain significant
quantities in the muscle,5 6 which may explain the inconsistent results
reported in studies of the effects of creatine on
athletic performance.
Creatine may increase exercise-related gains in lean body mass,7 8
9 though how much of these gains represents more muscle and how much is simply
water retention is unclear.10 Most, though not all, controlled studies have shown
that 20 grams per day of creatine monohydrate taken for five to six days by sedentary or
moderately active people, improves performance and delays muscle fatigue during
short-duration, high-intensity exercise such as sprinting or weight lifting.11
12 13 However, elderly people appear to gain only minimal, if any,
exercise performance benefits from creatine supplementation,14 15 and
performance outcomes for trained athletes using creatine supplements in competitive situations
have not been consistent.16 17 18 Creatine supplementation
does not appear to increase endurance performance and may impair it by contributing to weight
gain.19
Very little research has been done to investigate the exercise performance effects of
long-term (over one month) creatine supplementation. Two controlled long-term trials using
untrained women20 or trained men21 found that creatine improved gains
made in strength and lean body mass from weight-training programmes. However, a third
preliminary trial found only insignificant gains from creatine supplementation in
weight-training football players.22
The amount of creatine within cells may be deficient in people with muscular dystrophy.
This deficiency may contribute to the weakness and degeneration of muscle tissue seen in this
condition. A case report described a 9-year old boy with muscular dystrophy who experienced
improved muscle performance after creatine supplementation.23 A double-blind trial
found that creatine supplementation (10 grams per day for adults, 5 grams per day for
children) slightly but significantly improved muscle strength and performance of daily
activities in people with varying types of muscular dystrophy.24 Creatine
supplementation has also been reported to improve strength in certain rare diseases of muscle
and energy metabolism.25 26 27
For people with congestive heart failure,
intravenous creatine has been found to improve heart function, but oral supplementation has
not been effective, though skeletal muscle function does improve.28
29
A double-blind, study found that 20 grams per day of creatine taken for five days followed
by 10 grams per day for 51 days significantly lowered serum total cholesterol and triglycerides, but did not change either LDL or HDL
cholesterol, in both men and women.30 However, another double-blind trial found no
change in any of these blood levels in trained athletes using creatine during a 12-week
strength training programme.31 Creatine supplementation in this negative trial was
lower—only 5 grams per day was taken for the last 11 weeks of the study.
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. Harris RC, Soderlund K, Hultman E. Elevation of creatine in resting
and exercised muscle of normal subjects by creatine supplementation. Clin Sci
1992;83:367-74.
4. Green AL, Simpson EJ, Littlewood JJ, et al. Carbohydrate ingestion
augments creatine retention during creatine feeding in humans. Acta Physiol Scand
1996;158:195-202.
5. 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.
6. Casey A, Constantin-Teodosiu D, Howell S, et al. Creatine
supplementation favorably affects performance and muscle metabolism during maximal intensity
exercise in humans. Am J Physiol 1996;271:E31-E7.
7. Stone MH, Sanborn K, Smith LL, et al. Effects of in-season (5-weeks)
creatine and pyruvate supplementation on anaerobic performance and body composition in
American football players. Int J Sport Nutr 1999;9:146-65.
8. Earnest CP, Snell PG, Rodriguez R, et al. The effect of creatine
monohydrate ingestion on anaerobic power indices, muscular strength and body composition.
Acta Physiol Scand 1995;153:207-9.
9. 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.
10. Kreider RB, Ferreira M, Wilson M, et al. Effects of creatine
supplementation on body composition, strength, and sprint performance. Med Sci Sports
Exerc 1998;30:73-82.
11. Toler SM. Creatine is an ergogen for anaerobic exercise. Nutr
Rev 1997;55:21-5 [review].
12. Greenhaff PL. The nutritional biochemistry of creatine. J Nutr
Biochem 1997;8:610-8 [review].
13. Greenhaff PL, Casey A, Short AH, et al. Influence of oral creatine
supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man.
Clin Sci 1993;84:565-71.
14. Tarnopolsky MA. Potential benefits of creatine monohydrate
supplementation in the elderly. Curr Opin Clin Nutr Metab Care 2000;3:497-502
[review].
15. Rawson ES, Clarkson PM. Acute creatine supplementation in older men.
Int J Sports Med 2000;21:71-5.
16. Mujika I, Padilla S. Creatine supplementation as an ergogenic aid for
sports performance in highly trained athletes: a critical review. Int J Sports Med
1997;18:491-6.
17. Grindstaff PD, Kreider R, Bishop R, et al. Effects of creatine
supplementation on repetitive sprint performance and body composition in competitive swimmers.
Int J Sports Nutr 1997;7:330-46.
18. Peyrebrune MC, Nevill ME, Donaldson FJ, et al. The effects of oral
creatine supplementation on performance in single and repeated sprint swimming. J Sports
Sci 1998;16:271-9.
19. Balsom PD, Harridge SD, Soderlund K, et al. Creatine supplementation
per se does not enhance endurance exercise performance. Acta Physiol Scand
1993;149:521-3.
20. 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.
21. 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.
22. 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].
23. Felber S, Skladal D, Wyss M, et al. Oral creatine supplementation in
Duchenne muscular dystrophy: a clinical and 31P magnetic resonance spectroscopy study.
Neurol Res 2000;22:145-50.
24. Walter MC, Lochm�H, Reilich P, et al. Creatine
monohydrate in muscular dystrophies: A double-blind, placebo-controlled clinical study.
Neurology 2000;54:1848-50.
25. Tarnopolsky MA, Roy BD, MacDonald JR. A randomized, controlled trial
of creatine monohydrate in patients with mitochondrial cytopathies. Muscle Nerve
1997;20:1502-9.
26. Sipila I, Rapola J, Simell O, et al. Supplementary creatine as a
treatment for gyrate atrophy of the choroid and retina. N Engl J Med
1981;304:867-70.
27. Tarnopolsky M, Martin J. Creatine monohydrate increases strength in
patients with neuromuscular disease. Neurology 1999;52:854-7.
28. Andrews R, Greenhaff P, Curtis S, et al. The effect of dietary
creatine supplementation on skeletal muscle metabolism in congestive heart failure. Eur
Heart J 1998;19:617-22.
29. Gordon A, Hultman E, Kaijser L, et al. Creatine supplementation in
chronic heart failure increases skeletal muscle creatine phosphate and muscle performance.
Cardiovasc Res 1995;30:413-8.
30. Earnest CP, Almada AL, Mitchell TL. High-performance capillary
electrophoresis-pure creatine monohydrate reduces blood lipids in men and women. Clin
Sci 1996;91:113-8.
31. Volek JS, Duncan ND, Mazzetti SA, et al. No effect of heavy
resistance training and creatine supplementation on blood lipids. Int J Sport Nutr Exerc
Metab 2000;10:144-56.
32. Silber ML. Scientific facts behind creatine monohydrate as a sports
nutrition supplement. J Sports Med Phys Fitness 1999;39:179–88 [review].
33. Greenhaff PL. The nutritional biochemistry of creatine. J Nutr
Biochem 1997;8:610–8.
34. 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.
35. 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.
36. Hultman E, Soderlund K, Timmons J, et al. Muscle creatine loading in
man. J Appl Physiol 1996;81:232–7.
37. Green AL, Hultman E, Macdonald IA, et al. Carbohydrate ingestion
augments skeletal muscle creatine accumulation during creatine supplementation in man. Am
J Physiol 1996;271:E821–6.
38. Feldman EB. Creatine: a dietary supplement and ergogenic aid.
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39. Vandenberghe K, Gills N, Van Leemputte M, et al. Caffeine counteracts
the ergogenic action of muscle creatine loading. J Appl Physiol
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40. 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.
41. 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.
42. 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.
43. Earnest C, Almada A, Mitchell T. Influence of chronic creatine
supplementation on hepatorenal function. FASEB J 1996;10:4588.
44. Almada A, Mitchell T, Earnest C. Impact of chronic creatine
supplementation on serum enzyme concentrations. FASEB J
1996;10:4567.
45. 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.
46. Koshy KM, Griswold E, Schneeberger EE. Interstitial nephritis in a
patient taking creatine. N Engl J Med 1999;340:814–5 [letter].
47. Pritchard NR, Kaira PA. Renal dysfunction accompanying oral creatine
supplements. Lancet 1998;351:1252–3 [letter].
48. Hultman E, Soderlund K, Timmons J, et al. Muscle creatine loading in
man. J Appl Physiol 1996;81:232–7.
49. 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.
50. Juhn MS, Tarnopolsky M. Potential side effects of oral creatine
supplementation: a critical review. Clin J Sport Med 1998;8:298–304 [published
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