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The Various Effects of Creatine of Supplements

Jack Kuhlenschmidt

October 1, 2010


The supplementation of creatine has been subject to numerous rumors over the years. It has been debated whether or not the short-term, medium-term, and long-term usage of it can be considered a safe aid to muscles. This paper will analyze seven different studies on the various effects of creatine. Feldman (1999) conducted a study that compared older findings to current findings. She found that creatine was probably effective but the molecular mechanisms must be studied further. Poortmans and Francauz (1999) studied the long-term effects of creatine and disproved claims that the supplement impaired renal (kidney) function. Rawson, Clarkson, Price, and Miles (2002) found that younger subjects responded much more quickly to creatine than older ones did. Watanabe, Kato, and Tadafumi (2002) found that creatine increases mental stamina. Caffeine has also been found to counteract the desirable effects of creatine loading (Vandenberghe, Gillis, Leemputte, Hecke, Vanstapel, & Hespel, 1996). This paper also investigated obscure effects of creatine on meat products like chicken, but a study conducted by Young, Karlsson, and Henckel (2004) disproved these uses. Overall, however, this paper endorses the use of creatine to train with and boost natural production of phosphocreatine.


The Various Effects of Creatine as a Supplement


Creatine phosphate (also known as phosphocreatine) is a naturally produced molecule used in the body to create energy. It reacts with ADP to yield ATP and creatine, an organic acid that helps supply energy to and build muscle. In recent years, athletes and bodybuilders have taken creatine supplements in much larger than natural doses in order to add to the natural supply of creatine and therefore build more muscle and strength. Approximately 95% of the body’s naturally produced creatine is in muscle, with the rest residing in the brain and vertebrates. Creatine is also produced in animals, with every half-pound of meat carrying approximately one gram of the acid. Feldman (1999) reported that the earliest studies on creatine found that after 47 days of 10-20g creatine supplementation, creatine levels in muscles increased from 128 to 150 grams. These initial studies, conducted in 1910 and 1922, failed to consider any other effects that creatine might have. Until the late 1990s, there were not very many conclusive or efficiently conducted reports on what the negative effects of the supplementation might be. This is probably because creatine usage was slowly gaining popularity in athletes, but not popular enough to have studies dedicated towards it.

Today, creatine usage is widespread. Many high-school athletes, amateurs, and professionals are Feldman’s study (1999) was geared more towards the effects of creatine supplementation in terms of athletic performance and muscle growth. Up until recently, there were many unexplored areas of the effects of creatine. At the end of the study, Feldman (1999) suggested that the safety of long-term use, age differences, optimal sports, and hazardous drug interactions of creatine supplementation be further examined. This paper aims to touch upon all of these subjects in order to get a more complete view of creatine as a supplement for muscle development.


Moderators and Mediators

CREATINE USE IN DIFFERENT SPORTS. Creatine supplements increase the creatine levels in muscles, therefore increasing ATP and overall energy. Sports and physical exertion obviously require much more ATP than standing still or watching television. It would make sense to take creatine for anybody who wished to increase their energy during physical activities. Studies have shown, however, that this is not the case with creatine. Certain types of exercise and certain types of sports are benefited more through supplementation. Sprint activities, which require a lot of intensity in a short period of time, require energy almost exclusively provided from ATP and creatine stores (Feldman, 1999).  Higher creatine levels in a muscle also means that the muscle will be able to recover faster from exertion (Watanabe et al., 2002). Feldman (1999) suggested that the sports that are most suitable to this description are sprinting field events, baseball, volleyball, and football. These are all sports where adding muscle is usually deemed desirable and beneficial to play. Feldman’s (1999) paper also includes data from a June 4, 1998 USA Today poll regarding professional athletes and creatine. According to the poll, less than 25% of professional baseball players take creatine. The National Basketball Association has eight teams that approve of their players taking creatine powder (interesting, because basketball is not a sport associated with short bursts of high effort) and 11 teams that would not take a firm position on the subject. It should not come as a surprise which professional sport had the highest creatine-usage: football. According to the poll, half of NFL teams reported between 25% and 75% of their players to be on the supplement. An athlete playing a sport like football, where energy and mass are both key attributes to success, can be greatly improved through creatine supplementation.

Feldman (1999) went as far as to research the optimal intakes of the supplement for an athlete playing a sport like football or attempting to lift weights in a short and exertive manner. Athletes are to take between 15 and 30 grams per day for one week to increase muscle mass as well as overall short-term energy. After this time period, which can be referred to as the “loading” period, between two and five grams per day is required in order to completely maintain and gradually improve the desired effects. This maintenance is required for up to three months, at which point the athlete is advised to cleanse for at least one month to return the creatine in muscles to pre-supplement levels. Performance can still be boosted in endurance athletes, but the added bulk might become detrimental depending on how long-term the physical activity required of the athlete is.

LONG-TERM CREATINE USE vs. SHORT-TERM CREATINE USE. The short-term benefits of creatine use have already been discussed: increased muscle mass, greater strength, and a quicker ability to recover after exhaustion. Creatine use in short periods, such as a week or a month, is the standard in terms of athletic training. This is because there have been various claims stating that creatine use over a long duration of time leads to renal damage. Poortmans and Francaux (1999, page 1108) summarize the issue:

“Recently, it has been claimed by Pritchard and Kalra (15) that oral creatine may lead to renal dysfunction. Moreover, press releases have attributed the deaths of American wrestlers to creatine supplementation. … Nevertheless, it has been suggested that a long-term, nitrogen-rich diet might itself induce renal hyperfiltration and thereby contribute to the functional and structural deterioration of the kidney.”


In theory, the large amounts of nitrogen in creatine might have an effect on kidney filtration, but this study went deeper into the issue. The study took eight men and one woman, all highly trained athletes in perfectly healthy condition, and gave them regular doses of 1 to 20 g creatine, sometimes up to four times per day (Poortmans & Francaux, 1999). These daily doses were ingested for a period of 10 months to five years. Because this is a study on the effects of creatine on the kidneys of the subjects, the results were taken from blood and urine samples.

After analyzing the results, the study concluded that there were no differences between control subjects and creatine-supplemented subjects in terms of creatine clearance. There were clear differences in the urine, because obviously one group had creatine in their samples and the other did not, but the clearance rates in the urine showed that there were not any detrimental effects on the kidneys due to long-term creatine supplementation (Poortmans & Francaux, 1999). It can be concluded that both short-term and long-term supplementation can be constructive, it simply depends on what the athlete desires. Short-term will provide a large and almost immediate gain in muscle mass, and long-term will provide the initial gains as well as a continued gain in recovery time and short-term stamina.

THE EFFECTS OF CREATINE ON YOUNGER AND OLDER SUBJECTS. Rawson, Clarkson, Price, and Miles (2002) conducted a study comparing the effects of short-term creatine supplementation in young and elderly males. Eight young (24 ± 1.4 years) and seven elderly (70 ± 2.9 years) males ingested 20 g creatine each day for five days straight. The scientists hypothesized that the younger subjects would respond much more to the training than the older ones. Intuitive as it sounds, the results are still interesting. The younger group responded with 35% more phosphocreatine in their muscles, while the elderly subjects increased only 7% (Rawson et al., 2002). Keep in mind that this study is not about gains in strength or stamina, but solely about the levels of creatine in the subjects’ muscles. The study attributed the differences to either an inability for the older males to digest the creatine from their stomachs or just an ability to take more creatine in their muscles. The older you get, the less effective creatine as a supplement.

THE COMBINATION OF OTHER SUPPLEMENTS WITH CREATINE. There is only one substance that has been found to drastically change the effectiveness of creatine supplementation: caffeine. Vanderberghe, Gillis, Van Leemputte, Van Hecke, Vanstapel, & Hespel (1996) were the first to realize this counter-acting affect, and they came to the result completely by accident. Their hypothesis was that adding caffeine to normal creatine supplementation would even further elevate intramuscular creatine because of the stimulus properties of caffeine. Nine males aged 20-23 years old were split into three groups: control, creatine, and caffeine + creatine. Caffeine was found to completely counteract the beneficial effects of creatine supplementation. Caffeine has been shown to have no direct effects on high-intensity exercise performance (Vanderberghe et al., 1996). Interestingly enough, the study could not find a particular reason for the counteracting effect of the caffeine dose. This is definitely a weakness of the study, but the reasoning behind this lack of evidence is because of the paper’s initial intention: to prove that creatine is a more effective ergogenic aid when combined with caffeine.


Potential other uses for creatine

THE EFFECTS OF CREATINE ON MEAT PRODUCTS. Because creatine is present in both humans and animals, it is not an unreasonable hypothesis to state that supplementing a chicken with creatine would result in larger, more muscular birds. Young, Karlsson, and Henckel (2004) investigated this idea by feeding glucose, creatine, and water combination to chickens during their fasting period before slaughter. During fasting, the fecal combination of slaughter equipment and bacterial spoilage of carcasses are reduced. The plasma and glycogen stores decrease in normal fasting periods, and it is this fact that led the scientists to believe that a combination of glucose and creatine may slow the plasma and glycogen decreasing (Young et al., 2004). The results, however, were quite different. The color, temperature, and pH of the meat all came out undesirable in terms of meat quality. While this has nothing to do with creatine supplementation for humans, it is still important to research other possible uses for creatine. It is a very diverse supplement that might be able to have helpful effects on other things besides training.

THE EFFECT OF CREATINE ON MENTAL FATIGUE. The three places where creatine is most abundant in the human body are the muscles, the vertebrates, and the brain. Watanabe, Kato, and Tadafumi (2002) hypothesized that taking eight grams of creatine for five days would reduce mental fatigue in subjects performing math problems. The team used the Uchida-Kraepelin test, a simple math test that is considered the standard for measuring mental fatigue. They defined fatigue as a reduction of performance after continuous workload accompanied by a subjective feeling of exhaustion (Watanabe et al., 2002). They found no changes in the placebo patients, but creatine did slow mental fatigue in the supplemented patients. The study was sure to point out that the test results might have been due to increased muscle stamina and not increased mental stamina, but this is listed as a very unlikely cause, especially considering the fact that there is plenty of creatine in the human brain (Watanabe et al., 2002). The practicality of creatine loading to increase mental stamina was not analyzed, and it is in the opinion of this paper that it is most likely not practical for the average student or worker, but it is an interesting concept that a supplement considered for training use only also has a beneficial effect on mental stamina.



            In conclusion, it is safe to say that creatine is an effective and non-hazardous ergogenic aid. It is best suited to athletes who perform many repetitions for a short and intense duration. The best example of such a sport would be football or perhaps wrestling. The supplement helps build muscle as well as recovery time for these short periods of exertion. The claims of renal impairment have been disclaimed, and there have not been any other large issues raised on the subject. Creatine use has just recently become popular and there is still quite a bit of research to be done on the subject. Based upon the research that has currently been gathered, there is no reason to not endorse creatine as a powerful tool for training.








Works Cited


Feldman, Elaine B. "Creatine: A Dietary Supplement and Ergogenic Aid." (1999). Print.


Poortmans, Jacques R., and Marc Francaux. "Long-Term Oral Creatine Supplementation

Does Not Impair Renal Function in Healthy Athletes." (1999). Print.


Rawson, E.S., P.M. Clarkson, T.B. Price, and M.P. Miles. "Differential Response of

Muscle Phosphocreatine to Creatine Supplementation in Young and Old

Subjects." (2002). Print.


Vanderberghe, K., N. Gillis, M. Van Leemputte, P. Van Hecke, F. Vanstapel, and P.

Hespel. "Caffeine Counteracts the Ergogenic Action of Muscle Creatine

Loading." (1996). Print.


Watanabe, Airi, Nobumasa Kato, and Tadafumi. "Effects of Creatine on Mental Fatigue

and Cerebral Hemoglovin Oxygenation." (2002). Print.


Young, JF, AH Karlsson, and P. Henckel. "Water-Holding Capacity in Chicken Breast

Muscle Is Enhanced by Pyruvate and Reduced by Creatine Supplements." (2004).





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