It amazes me that there is still such a misunderstanding surrounding creatine supplementation. To this day I still get questions regarding the effectiveness and safety of creatine use.
Creatine is one of the most popular supplements on the market in terms of recreational use AND research attention. A pubmed.com (a database allowing free access to the abstracts of the majority of scientific research studies regarding health and performance) search of "creatine" returns 40,928 articles, including 1,989 review articles. "Creatine supplementation" returns 921 articles, and 117 reviews. I think it's safe to say the research community has looked into it.
The reasons for the confusion are becoming increasingly frustrating. Many misnomers about creatine stem from steroid users claiming they only take creatine, academics pointing out that it is found naturally in food and therefore unnecessary to supplement, and physicians (among others) acknowledging that there aren't studies measuring the effects of long-term creatine supplementation.
Next time someone makes this latter point, ask them to provide you with research evidence describing the long-term safety of daily peanut butter consumption, or the long-term effects of chronic orange juice ingestion.
Like just about every supplement (and most food for that matter), it is not financially or experimentally practical to conduct a long-term study detailing the physiological changes associated with creatine use.
As in other cases, we can make reasonable conclusions about both the long-term safety and efficacy of supplementation by analyzing these measures in short- and medium-term studies. On a personal note, I've been taking creatine relatively consistently for well over 5 years. I still haven't grown gills. I know several other people who have also taken creatine for extended periods of time, also gill-free.
How It Works
I'm going to keep this part brief, as the physiological processes by which creatine assists in energy production have been well described by many authors already.
Essentially, creatine (in the form of phosphocreatine; PCr) undergoes a reaction with adenosine diphosphate (ADP) to create adenosine triphosphate (ATP) and creatine.
ATP & ADP
Adenosine Triphosphate (ATP) is an adenine nucleotide bound to three phosphates, manufactured in the mitochondria.
Adenosine diphosphate (ADP) is the end-product that results when ATP loses one of its phosphate groups located at the end of the molecule. The conversion of these two molecules plays a critical role in supplying energy for many processes of life.
ATP is basically just energy. Free ATP can be used rapidly by the body to produce force and therefore movement. Although ATP can be formed by other sources (e.g. glycolysis using glycogen stores and beta oxidation using free fatty acids), this PCr system is significant because it produces ATP more rapidly than these other pathways and doesn't require oxygen (as in aerobic glycolysis and beta oxidation).
Although creatine is not a source of energy, it acts as a shuttle, supplying your muscles with even more ATP during anaerobic activity. The idea is that by providing the body with additional creatine, muscle concentrations will increase, thereby extending the amount of time that this rapid ATP-producing system can provide energy to the body for high-intensity movements.
Returning to the large body of research concerning creatine supplementation, let's take a look at some of the documented benefits. One group of authors concluded that creatine was "the most effective nutritional supplement available to athletes to increase high intensity exercise capacity and muscle mass during training."1
Studies utilizing creatine supplementation typically range from 4-12 weeks, with the supplement group gaining 2-5 more pounds of lean muscle mass than the control group.2-5 Combining creatine with whey protein also leads to greater gains in lean muscle mass than just whey protein alone6 possibly by improving protein synthesis.7,8
The process by which nitrogen from amino acids is linearly arranged into structural proteins through the involvement of RNA and various enzymes. Protein synthesis is muscle growth. The more efficient you can make this process the more efficiently you can build muscle.
Personally, I'm less concerned with how big I am than how strong I am. In one study, Arciero et al. (2001) reported that 40% of the increase in strength over a 4-week training period could be attributed to the effects of creatine.9
Similarly, Rawson and Volek (2003) found that on average, the increase in strength/lifting performance was 8-14% greater in the creatine and training group, compared to the placebo and training group.10
Creatine supplementation may also improve work capacity, especially in activities involving repeated high-intensity efforts such as weight-lifting and sprinting.2,11 I should point out that another study did not find any benefit in repeat sprint performance in hockey players.12 However, it is possible that the dose was not sufficient to elicit the desired response (0.3g/kg body mass/day) or the sample size (9 in creatine group; 8 in control group) was too small to produce a statistically significant difference.
Creatine may also benefit work capacity by improving the ability to store carbohydrates, which could have positive performance implications for athletes of most sports.13-15 Coincidently consuming creatine and carbohydrates tends to optimize the absorption of both.16
The benefits of supplemental creatine extend well beyond improvements in muscle mass, strength and work capacity. In fact, there is even some evidence that creatine supplementation may positively affect performance on complex mental tasks in a state of sleep deprivation.17
In animal models, there is some evidence that creatine supplementation may have a protective effect for neurodegenerative diseases such as Huntington's disease, Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis (Lou Gehrig's disease).
What Is Huntington's Disease?
Huntington's disease, also called Huntington's chorea, chorea major, or HD, is a genetic neurological disorder characterized after onset by uncoordinated, jerky body movements called chorea and a decline in some mental abilities, which can lead to affected aspects of behavior. As the disorder progresses, these symptoms cause complications that reduce life expectancy.
What Is Parkinson's Disease?
Parkinson's disease is a degenerative disorder of the central nervous system that often impairs the sufferer's motor skills, speech, and other functions.
What Is Alzheimer's Disease?
Alzheimer's disease is the most common form of dementia. This incurable, degenerative, and terminal disease was first described by German psychiatrist Alois Alzheimer in 1906. Generally it is diagnosed in people over 65 years of age, although the less-prevalent early-onset Alzheimer's can occur much earlier.
What Is Amyotrophic Lateral Sclerosis?
Amyotrophic Lateral Sclerosis (ALS, sometimes called Maladie de Charcot, or, in the United States, Lou Gehrig's Disease) is a progressive, usually fatal, neurodegenerative disease caused by the degeneration of motor neurons, the nerve cells in the central nervous system that control voluntary muscle movement.
Furthermore, oral creatine supplementation may decrease homocysteine production, decreasing the risk of various forms of cardiovascular disease.18
Because of all of these potential benefits, and the previously discussed benefits on muscle mass and strength, attention is moving from oral creatine supplementation for improved athletic performance to improved quality of life in the elderly.19
Dosage And Timing
Research on effective dosages is relatively consistent. Typically 20-30g/day for 5-7 days is used as a "loading" period. One study found that 20g/day for 5-6 days increased the muscular creatine concentration by 25 mmol/kg dry mass, 30% of which was in the form of phosphocreatine.20
Interestingly, these authors reported that "In individuals in whom the initial total creatine concentration already approached 150 mmol/kg dry mass, neither creatine uptake nor an effect on phosphocreatine resynthesis or performance was found after supplementation." This suggests a ceiling effect and potential reason for why some people are classified as "non-responders."
Similar loading dosages have been found to increase PCr concentration by 12-18%.21 Typically, following this "loading" period, individuals take 5g/day to maintain the elevated PCr levels, although there is some evidence that elevated levels can be maintained with as little as 2g/day.22
One studied examined absorption differences of various forms of creatine. In their words, "We conclude that creatine administered as meat or in solid form is readily absorbed but may result in slightly lower peak concentrations than when the same dose is ingested as a solution."23
In summary, it appears that a loading phase as described above, followed by a maintenance phase is effective in elevating creatine stores in the body. There is some debate as to whether it is necessary to load creatine at all, opposed to simply taking 5g/day consistently.
To the best of my knowledge, there is evidence supporting both sides of this argument. Frankly, since loading phases have consistently shown to be safe (as described below) and effective, and because creatine is relatively inexpensive, I don't see a reason to avoid loading.
However, if you don't notice any difference between loading and not loading, save yourself some creatine and don't load. Because of the effects of taking creatine along with both a whey protein drink and carbohydrates, taking creatine immediately following training with a simple carbohydrate and whey protein drink will probably best facilitate rapid absorption.
I always like to emphasize that research findings are very specific to the studied sample and may not be generalizable to everyone. Especially with supplements, the key is to, within the realm of safety, try different things and determine what works best for you.
The two primary safety concerns associated with creatine use are muscle cramping and kidney health. Anecdotal reports of muscle cramping have been prevalent since creatine supplementation increased in popularity about a decade ago. However, research has not supported any link between creatine use and muscle cramping.24,25
In my opinion, the incidences of cramping associated with supplement use can be explained by an existing state of dehydration. In light of the fact that the majority of Americans are chronically dehydrated (roughly 75%) and the addition of any supplement (or caloric intake for that matter) requires additional water, it doesn't surprise me that some people complain of cramping.
With regards to kidney health, one study found that "Following acute ingestion (4-5 days) of large amounts of creatine, creatinine concentrations increased slightly, but not to a clinically significant concentration. Creatinine is also only minimally affected by longer creatine supplementation (up to 5.6 y)."26
Creatine supplementation does not appear to negatively impact kidney health in individuals with healthy kidneys. This may not be the case for individuals who already have some predisposition to kidney disease.
Supplemental creatine may be an option worth exploring if you're a male or female of any age that is looking to improve lean muscle mass, strength, and work capacity as well as fend off neurological and cardiovascular diseases. If you are not part of the male or female population of any age, and wish to be small, weak, tired, and disease infested, creatine is definitely not the right choice for you.
- Kreider, R.B., Almada, A.L, Antonio, J., Broeder, C., Earnest, C., Greenwood, M. et al. (2004). ISSN Exercise & Sport Nutrition Review: Research & Recommendations. Sports Nutrition Review Journal, 1, 1-44.
- Kreider, R.B. (2003). Effects of creatine supplementation on performance and training adaptations. Molecular and Cellular Biochemistry, 244, 89-94.
- Willoughby, D.S., & Rosene, J.M. (2003). Effects of oral creatine and resistance training on myogenic regularly factor expression. Medicine and Science in Sports and Exercise, 35, 923-929.
- Willoughby, D.S., & Rosene, J. (2001). Effects of oral creatine and resistance training on myosin heavy chain expresion. Medicine and Science in Sports and Exercise, 33, 1674-1681.
- Volek, J.S., Duncan, N.D., Mazzetti, S.A., Staron, R.S., Putukian, M., Gomez, A.L., et al. (1999). Performance and muscle fiber adaptations to 12 weeks of creatine supplementation and heavy resistance training. Medicine and Science in Sports and Exercise, 31, 1147-1156.
- Burke, D.G., Chilibeck, P.D., Davidson, K.S., Candow, D.G., Farthing, J., & Smith-Palmer, T. (2001). 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, 349-364.
- Lemon, P.W. (2000). Beyond the zone: Protein needs of active individuals. Journal of the American College of Nutrition, 19, 513S-521S.
- Ingwall, J.S. (1976). Creatine and the control of muscle-specific protein synthesis in cardiac and skeletal muscle. Circulation Research, 38, I115-123.
- Arciero, P.J., Hannibal, N.S., III, Nindl, B.C., Gentile, C.L., Hamed, J. & Vukovich, M.D. (2001). Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow. Metabolism, 50, 1429.
- Rawson, E.S., & Volek, J.S. (2003). Effects of Creatine Supplementation and Resistance Training on Muscle Strength and Weightlifting Performance. Journal of Strength and Conditioning Research, 17, 822-831.
- Jones, A.M., Atter, T., & Georg, K.P. (1999). Oral creatine supplementation improves multiple sprint performance in elite ice-hockey players. The Journal of Sports Medicine and Physical Fitness, 39, 189-196.
- Cornish, S.M., Chilibeck, P.D., & Burke, D.G. (2006). The effect of creatine monohydrate supplementation on sprint skating in ice-hockey players. The Journal of Sports Medicine and Physical Fitness, 46, 90-98.
- Derave, W., Op'T Eijinde, B., Richter, E.A., & Hespel, P. (2001). Combined creatine and protein supplementation improves glucose tolerance and muscle glycogen accumulation in humans. Abstracts of the 6th International Conference on Guanidino Compounds in Biology and Medicine.
- Nelson, A.G., Arnall, D.A., Kokkonen, J., Day, & Evans, J. (2001). Muscle glycogen supercompensation is enhanced by prior creatine supplementation. Medicine and Science in Sports and Exercise, 33, 1096-1100.
- Op'T Eijinde, B., Urso, B., Richter, E.A., Greenhaff, P.L., & Hespel, P. (2001). Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization. Diabetes, 50, 18-23.
- Green, A.L., Hultman, E., Macdonald, I.A., Sewell, D.A., & Greenhaff, P.L. (1996). Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. American Journal of Physiology, 271, E821-E826.
- McMorris, T., Harris, R.C., Howard, A.N., Langridge, G., Hall, B., Corbett, J., Dicks, M., & Hodgson, C. (2007). Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior. Physiology and Behavior, 90, 21-28.
- Wyss, M., & Schulze, A. (2002). Health implications of creatine: Can oral creatine supplementation protect against neurological and atherosclerotic disease? Neuroscience, 112, 243-260.
- Tarnopolsky, M.A. (2000). Potential benefits of creatine monohydrate supplementation in the elderly. Current Opinion in Clinical Nutrition and Metabolic Care, 3, 497-502.
- Casey, A., & Greenhaff, P.L. (2000). Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? The American Journal of Clinical Nutrition, 72, 607S-617S.
- Juhn, M.S., & Tranopolsky, M. (1998). Oral creatine supplementation and athletic performance: A critical review. Clinical Journal of Sports Medicine, 8, 286-297.
- Hultman, E., Soderlund, K., Timmons, J.A., Cederblad, G., & Greenhaff, P.L. (1996). Muscle creatine loading in men. Journal of Applied Physiology, 81, 232-237.
- Harris, R.C., Nevill, M., Harris, D.B., Fallowfield, J.L., Bogdanis, G.C., & Wise, J.A. (2002). Absorption of creatine supplied as a drink, in meat or in solid form. Journal of Sports Sciences, 20, 147-151.
- Dalbo, V.J., Roberts, M.D., Stout, J.R., & Kerksick, C.M. (2008). Putting to rest the myth of creatine supplementation leading to muscle cramps and dehydration. British Journal of Sports Medicine, 42, 567-573.
- Greenwood, M., Kreider, R.B., Melton, C., Rasmussen, C., Lancaster, S., Cantler, E., Milnor, P., & Almada, A. (2003). Creatine supplementation during college football training does not increase the incidence of cramping or injury. Molecular and Cellular Biochemistry, 244, 83-88.
- Pline, K.A., & Smith, C.L. (2005). The effect of creatine intake on renal function. The Annals of Pharmacotherapy, 39, 1093-1096.