Over the last decade, thousands of articles have been written about creatine supplementation in scientific journals, magazines, newspapers, and on the Internet. The reason for this interest is that creatine supplementation has proven to be one of the most effective methods available to increase strength, power, and muscle mass.¹ Moreover, a number of potential therapeutic benefits of creatine supplementation have been suggested for various patient populations.² Despite this impressive body of research, concerns have been raised about the safety of creatine supplementation and ethics of athletes taking performance-enhancing nutritional supplements.^3,4 While a number of very good reviews have been published about creatine in the scientific literature^1,2,5-8 a significant amount of misinformation has been written about creatine, particularly in the popular media. Additionally, several nutritional supplement companies have attempted to gain market share by perpetuating some of these creatine myths. The result is that people are often confused about the potential benefits and risks of creatine supplementation. The purpose of this article is to provide an update on the state of the science regarding creatine supplementation as well as to answer some common questions about creatine so that you can make an informed decision about whether to use creatine or not.

What is Creatine?
Creatine is a naturally occurring amino acid-like compound that is found primarily in the muscle (95%). There is also a small amount of creatine in the brain and testes. About two thirds of creatine found in the muscle is stored as phosphocreatine (PCr) while the remaining amount of creatine is stored as free creatine. The total creatine pool (PC + free creatine) in the muscle averages about 120 grams for a normal sized person. However, the body has the capacity to store up to 160 grams of creatine under certain conditions.

Sources of Creatine
The body breaks down 1 to 2% of the creatine pool per day (about 2 grams) into creatinine in the muscle. The creatinine is then excreted in urine. The body can replenish depleted creatine in two ways. First, about half of your daily creatine needs can be obtained from your normal diet by eating foods that contain creatine. For example, there is about 1 to 2 grams of creatine in a pound of uncooked beef and salmon. The remaining amount of creatine is synthesized from the amino acids glycine, arginine, and methionine. Normal dietary intake of creatine from food and creatine synthesis typically maintains creatine levels at about 120 grams for a normal size individual. Vegetarians have been reported to have lower than normal muscle creatine stores. Additionally, some people have been found to have creatine synthesis deficiencies and therefore must depend on dietary availability of creatine to maintain normal muscle concentrations.

Supplementation Protocols
The most common way to increase muscle creatine stores is to "load" creatine by taking 5 grams of creatine monohydrate four times per day for 5 to 7 days. Studies show that this protocol can increase muscle creatine and PC by 10 to 40%.² Once muscle creatine stores are saturated, studies indicate that you only need to take 3 to 5 grams of creatine monohydrate per day in order to maintain elevated creatine stores. An alternative supplementation protocol is to ingest 3 grams/day of creatine monohydrate for 28-days ⁹. Studies show that this method can increase muscle concentrations of creatine as effectively as creatine loading techniques. However, this method would only result in a gradual increase in muscle creatine content compared to the more rapid loading method. Some athletes also cycle on and off creatine by taking loading doses of creatine monohydrate for 3 to 5 days every 3 to 4 weeks during training. Theoretically, since it takes 4 to 6 weeks for elevated creatine stores to return to baseline, this protocol would be effective in increasing and maintaining elevated creatine stores over time ¹.

Effects of Creatine Supplementation on Muscle Creatine Stores
Numerous studies indicate that dietary supplementation of creatine monohydrate increases muscle creatine and phosphocreatine (PC) content by 10 to 40% ^2,9. In simple terms, one can think of the normal creatine content of the muscle (about 120 grams) as being a gas tank that is 3/4 full. Creatine supplementation typically allows an individual to fill up their creatine storage tank up to 150 to 160 grams (i.e., 20 to 30%). It should be noted that the amount of creatine retained in the muscle following creatine supplementation depends on the amount of creatine in the muscle before supplementation. Individuals with low creatine content in muscle prior to supplementation may increase creatine stores by 20 to 40% while individuals with relatively high creatine levels before supplementation may only experience a 10 to 20% increase in muscle creatine content. Performance changes in response to creatine supplementation have been correlated with the magnitude of increase in muscle creatine levels. ^10,11 Once creatine levels are elevated and an individual stops taking creatine, studies indicate it may take 4 to 6 weeks before creatine levels return to baseline.¹² There is no evidence that muscle creatine levels fall below baseline after cessation of creatine supplementation, which might suggest a long-term suppression of endogenous creatine synthesis. ^2,13

Theoretical Benefits of Creatine Supplementation
Increasing muscle availability of creatine and PC can affect exercise and training adaptations in several ways. First, increasing the availability of PC in the muscle may help maintain availability of energy during high intensity exercise, like sprinting and weightlifting. Second, increasing the availability of PC may help speed recovery between sprints and/or bouts of intense exercise. These adaptations would allow an athlete to do more work over a series of sprints and/or sets of exercise theoretically leading to greater gains in strength, muscle mass, and/or performance over time. For this reason, creatine supplementation has primarily been recommended as an ergogenic aid for power/strength athletes. However, recent research indicates that endurance athletes may also benefit from creatine supplementation. In this regard, studies indicate creatine loading prior to carbohydrate loading promotes greater glycogen retention ¹⁴. Additionally, studies indicate that ingesting creatine with carbohydrate during carbohydrate loading promotes greater creatine and glycogen retention ^15-18. Theoretically, this may improve glycogen availability for endurance athletes. Creatine has also been shown to improve repetitive sprint performance. Since endurance athletes employ interval training techniques in an attempt to improve speed and anaerobic threshold, creatine supplementation during training may improve interval training adaptations leading to improved performance. Finally, studies also indicate that creatine supplementation can help maintain body weight and muscle mass during training. Since many endurance athletes have difficulty maintaining body mass during training, creatine supplementation may help maintain optimal body composition.

Effects of Creatine on Exercise Performance or Training Adaptations
As of this writing, there have been more than one thousand articles published in the peer-reviewed scientific literature on creatine supplementation. Slightly over half of these studies have evaluated the effects of creatine supplementation on exercise performance. The majority of these studies (about 70%) indicate that creatine supplementation promotes a statistically significant improvement in exercise capacity ⁶. This means that 95 times out of 100, if you take creatine as described in the study, you will experience an improvement in exercise performance. The average gain in performance from these studies typically ranges between 10 to 15%. For example, short-term creatine supplementation has been reported to improve maximal power/strength (5-15%), work performed during sets of maximal-effort muscle contractions (5-15%), single-effort sprint performance (1-5%), and work performed during repetitive sprint performance (5-15%).⁶ Long-term creatine supplementation appears to enhance the quality of training generally leading to 5 to 15% greater gains in strength and performance.6 Nearly all studies indicate that creatine supplementation increases body mass by about 1 to 2 kg in the first week of loading.6 In training studies, subjects taking creatine typically gain twice as much body mass and/or fat free mass (i.e., an extra 2 to 4 pounds of muscle mass during 4 to 12 weeks of training) than subjects taking a placebo. No study has reported that creatine supplementation significantly impairs exercise capacity. Although all studies do not report significant results, the preponderance of scientific evidence indicates that creatine supplementation appears to be an effective nutritional ergogenic aid for a variety of exercise tasks in a number of athletic and clinical populations.^1,6 The following highlights some of the recent research that has evaluated the effects of short and long-term creatine supplementation on exercise performance and/or training adaptations.

Short-Term Supplementation
Numerous studies have been conducted to evaluate the effects of short-term creatine supplementation (3-7 days) on exercise performance. For example, Volek and colleagues ¹⁹ reported that creatine supplementation (25 grams/day for 7 days) resulted in a significant increase in the amount of work performed during five sets of bench press and jump squats in comparison to a placebo group. Tarnopolsky and coworkers ²⁰ reported creatine supplementation (20 grams/day x 4 days) increased peak cycling power, dorsi-flexion maximal voluntary contractions (MVC) torque, and lactate in men and women with no apparent gender effects. Moreover, Wiroth and colleagues ²¹ reported that creatine supplementation (15 grams/day x 5 days) significantly improved maximal power and work performed during 5 x 10-s cycling sprints with 60-s rest recovery in younger and older subjects.

Creatine supplementation has also been shown to improve exercise performance during various sport activities. For example, Skare and associates ²² reported that creatine supplementation (20 grams/day) decreased 100-m sprint times and reduced the total time of 6 x 60-m sprints in a group of well-trained adolescent competitive runners. Mujika and colleagues ²³ reported that creatine supplementation (20 grams/day x 6 days) improved repeated sprint performance (6 x 15m sprints with 30-s recovery) and limited the decay in jumping ability in 17 highly trained soccer players. Similarly, Ostojic and coworkers ²⁴ reported that creatine supplementation (30 grams/day for 7 days) improved soccer-specific skill performance in young soccer players. Theodorou et al ²⁵ reported that creatine supplementation (25 grams/day x 4-days) significantly improved mean interval performance times in 22 elite swimmers. Mero and colleagues ²⁶ reported that supplementation of creatine (20 grams/day) for 6-d combined with sodium bicarbonate (0.3 grams/kg) ingestion 2-h prior to exercise significantly improved 2x100m swim performance. Finally, Preen and associates ²⁷ evaluated the effects of ingesting creatine (20 grams/day x 5 days) on resting and post-exercise creatine and PC content as well as performance of an 80-min intermittent sprint test (10 sets of 5-6 x 6-s sprints with varying recovery intervals). The authors reported that creatine increased resting and post-exercise creatine and PC content, mean work performed, and total work performed during 6 x 6-s sets with 54-s and 84-s recovery. In addition, work performed during 5 x 6-s sprints with 24-s recovery tended to be greater. Collectively, these findings and many others indicate that creatine supplementation can significantly improve performance of athletes in a variety of sport-related field activities.

Long-Term Supplementation. Theoretically, increasing the ability to perform high-intensity exercise may lead to greater training adaptations over time. Consequently, a number of studies have evaluated the effects of creatine supplementation on training adaptations. For example, Vandenberghe et al ¹²²⁸ reported that creatine supplementation (20 grams/day x 5 days; 0.1 or 0.3 grams/kg/day of FFM x 51-d) in conjunction with resistance and speed/agility training significantly improved 40-yd dash time and bench press strength in 39 college athletes. Kreider and associates ²⁹ reported that creatine supplementation (15.75 grams/day x 28-days) during off-season college football training promoted greater gains in FFM and repetitive sprint performance in comparison to subjects ingesting a placebo. Likewise, Stone et al ³⁰ reported that 5-weeks of creatine ingestion (~10 or 20 grams/day with and without pyruvate) promoted significantly greater increases in body mass, FFM, 1 RM bench press, combined 1 RM squat and bench press, vertical jump power output, and peak rate of force development during in-season training in 42 Division IAA college football players.

Volek and coworkers ³¹ reported that 12-weeks of creatine supplementation (25 grams/day x 7 days; 5 grams/day x 77 days) during periodized resistance training increased muscle total creatine and PC, FFM, type I, IIa, and IIb muscle fiber diameter, bench press and squat 1 RM, and lifting volume (weeks 5-8) in 19 resistance-trained athletes. Kirksey and colleagues ³² found that creatine supplementation (0.3 grams/kg/day x 42 days) during off-season training promoted greater gains in vertical jump height and power, sprint cycling performance, and FFM in 36 Division IAA male and female track and field athletes. Moreover, Jones and collaborators ³³³⁴ reported that creatine supplementation (20 grams/day x 7 days; 10 grams/day x 14 days) significantly increased FFM and cumulative strength gains during training in 40 subjects initiating training. Additional gains were observed when 3 grams/day of calcium beta-hydroxy-beta-methylbutyrate (HMB) was co-ingested with creatine. Finally, Willoughby and associates ³⁵ reported that in comparison to controls, creatine supplementation (6 grams/day x 12 weeks) during resistance training (6-8 repetitions at 85-90%; 3 x weeks) significantly increased total body mass, FFM, and thigh volume, 1 RM strength, myofibrillar protein content, Type I, IIa, and IIx myosin heavy chain (MHC) mRNA expression, and MHC protein expression. In a subsequent paper, Willoughby and colleagues 36 reported that Cr supplementation (6 grams/day x 12 weeks) increased M-CK mRNA expression apparently due to increases in the expression of myogenin and MRF-4. The researchers concluded that increases in myogenin and MRF-4 mRNA and protein may play a role in increasing myosin heavy chain expression. These data indicate that creatine supplementation can directly influence muscle protein synthesis. Collectively, these studies and others provide strong evidence that creatine supplementation during intense resistance training leads to greater gains in strength and muscle mass.

Possible Medical Uses of Creatine
Creatine and phosphocreatine are involved in numerous metabolic processes. Creatine synthesis deficiencies and/or abnormal availability of creatine and PC have been reported to cause a number of medical problems. For this reason, the potential medical uses of creatine have been investigated since the mid 1970s. Initially, research focused on the role of creatine and/or creatine phosphate in reducing heart arrhythmias and/or improving heart function during ischemia events (i.e., lack of oxygen) ¹. Initial studies also evaluated the effects of treating various medical populations who had creatine deficiences (i.e., gyrate atrophy, infants and children with low levels of PC in the brain, etc). Interest in the potential medical uses of creatine has increased over the last ten years. Researchers have been particularly interested in determining whether creatine supplementation may reduce rates of atrophy and/or muscle wasting; speed the rate of recovery from musculoskeletal and/or spinal cord injuries; and improve strength and muscle endurance in patients with various neuromuscular diseases.^1,2 For example, researchers have been evaluating whether creatine supplementation^37-41 muscular dystrophy, ^42-4445-49 Huntington's disease, ^50-53 amyotrophic lateral sclerosis or Lou Gerhig's Disease, ^54-57 arthritis, ⁵⁸ diabetes, ⁵⁹ high cholesterol and triglyceride levels, ^29,60 and elevated homocysteine levels.^61-64 Other studies have reported that creatine supplementation during training reduces injury rates in athletes ^65-69 and/or allows athletes to tolerate intensified training to a greater degree.⁷⁰ Although more research is needed, some promising results have been reported in a number of studies suggesting that creatine may have therapeutic benefits in certain patient populations.

Common Questions About Creatine reported that in comparison to a placebo group, creatine supplementation (20 grams/day x 4 days; 5 grams/day x 65 days) during 10-weeks of training in women increased total creatine and PC content, maximal strength (20-25%), maximal intermittent exercise capacity of the arm flexors (10-25%), and fat free mass (FFM) by 60%. In addition, the researchers reported that creatine supplementation during 10-weeks of detraining helped maintain training adaptations to a greater degree. Noonan and collaborators reported that creatine (20 grams/day x 5 days; 5 grams/day x 10 weeks) promoted greater gains in sprint performance (5 x 15-s with 15-s recovery) and average on-ice sprint performance (6 x 80-m sprints) in 16 elite ice-hockey players. Interestingly, Jowko et al may improve clinical outcomes in patients with brain and/or spinal cord injuries, myophathies,

Are There Any Side Effects from Creatine? The only side effect reported in the scientific and medical literature from creatine supplementation has been weight gain.^1,2,71 However, there have been a number of anecdotally reported side effects reported in the popular literature such as gastrointestinal distress, muscle cramping, dehydration, and increased risk to musculoskeletal injury (i.e., muscle strains/pulls). Additionally, there has also been concern that short and/or long-term creatine supplementation may increase renal stress and/or adversely affect the muscles, liver, or other organs of the body. Over the last few years a number of studies have attempted to assess the medical safety of creatine. These studies indicate that creatine is not associated with any of these anecdotally reported problems.^66,72-80 In fact, there is recent evidence that creatine may lessen heat stress and reduce the susceptibility to musculoskeletal injuries among athletes engaged in trainin.^66,79,80 While people who take creatine may experience some of these problems, the incidence of occurrence in creatine users does not appear to be greater than subjects who take placebos and in some cases have been reported to be less.⁷³

What is the Best Form of Creatine to Take? Nearly all studies on creatine supplementation have evaluated pharmacuetical grade creatine monohydrate in powder form or have used oral or intravenous phosphocreatine formulations (a more expensive form of creatine). However, since creatine has become a popular supplement, there are a number of different forms of creatine that have been marketed (e.g., creatine candy/bars, liquid creatine, creatine gum, creatine citrate, effervescent creatine, etc). Many of these forms of creatine claim to be better than creatine monohydrate. However, I am aware of no data that indicates that any of these forms of creatine increases creatine uptake to the muscle better than creatine monohydrate. In fact, a recent study from my lab indicated that liquid creatine has no effect on muscle creatine store.81 A few published studies have compared the ergogenic value of several of these types of supplements to creatine monohydrate. However, results have generally indicated that although some of these supplements (i.e., creatine candy, creatine gum, and effervescent creatine) can improve exercise capacity, they do not appear to work any better than creatine monohydrate. Consequently, the only potential benefits that I see from many of these different forms of creatine are convenience, supplement variety, and/or taste preferences. The greatest disadvantage, however, is that many of these supplements are more expensive than creatine monohydrate. There is absolutely no evidence that you can take less of these types of supplements (e.g., liquid creatine or effervescent creatine) and get the same benefits as you would by ingesting higher amounts of creatine monohydrate, due to less degradation in the stomach, greater intestinal absorption, faster absorption in the blood, and/or greater muscle uptake. Finally, there are three primary sources for creatine (Germany, the U.S., and China). Independent testing has revealed that Chinese sources of creatine may have less purity and/or contain higher amounts of contaminants like dicyandiamide, dihydrotriazine, and/or creatinine (converted form of creatine). The best raw sources of creatine monohydrate appear to be from Germany (e.g., AlzChem CreaPure®) or the U.S. (e.g., Ferro Pfansteihl). Care should be taken to only purchase high-quality creatine monohydrate that is produced in inspected facilities that adhere to FDA good manufacturing practice guidelines.

Should I Load or Not? Research has shown that the most rapid way to increase muscle creatine stores is to follow the loading method described above. Most of the creatine is taken up by muscle during the first 2 to 3 days of the loading period. While there is one study that suggests that taking lower doses of creatine over time (3 grams/day for 28 days) increased muscle creatine content,⁹ it is less clear whether this low-dose protocol enhances exercise capacity. There are only a few well-controlled studies that reported that low-dose creatine supplementation (5-6 grams/day of creatine for 10 weeks) promoted greater gains in strength and muscle mass during training.^35,36,82

Should I Take Creatine Alone or With Other Nutrients? There has been considerable interest in finding ways to enhance muscle uptake of creatine. Many commercially available supplements boast of new improved transport systems that optimize creatine storage via greater intestinal and/or muscle uptake. Do other nutrients affect muscle concentrations and/or performance? Before I answer this question, it is important that you know some of the creatine basics. First, research since the early 1900's has indicated that orally ingested creatine monohydrate is absorbed intact through the intestine into the blood. The creatine is then either taken up by the muscle or excreted as creatine in the urine. Creatine is not degraded into creatinine in the stomach and intestinal absorption is not a limiting factor to muscle uptake of creatine. In fact, one of the ways we determine muscle creatine storage is by subtracting urine creatine output from oral creatine intake. If a significant amount of creatine was not digested or degraded to creatinine in the stomach (its only known byproduct), these measurements would be invalid. Second, creatine uptake into the muscle has been reported to be sodium dependent and mediated by insulin. This means that ingesting creatine with large amounts of glucose (e.g., 80 - 100 grams) or carbohydrate/protein (e.g., 50 - 80 grams of carbohydrate with 30 - 50 grams of protein), which is known to increase blood insulin levels, may be an effective way to enhance creatine uptake.^81,83-8686 Consequently, I recommend that athletes take creatine with a high carbohydrate drink (e.g., juice or concentrated carbohydrate solution) or with a carbohydrate/protein supplement in order to increase insulin and promote creatine uptake.

A number of creatine-containing formulations, protein , vitamins and minerals, and/or other potentially ergogenic nutrients (e.g., HMB, sodium phosphates, bicarbonate, taurine, etc) may provide some added and/or independent benefits.^{26,29,34,86-88} For example, our research has shown the greatest increase in muscle mass from creatine supplementation occurred when creatine was added to a vitamin/mineral fortified carbohydrate/protein supplement.^87,89 It is possible that adding other nutrients like Arginine Alpha-Ketoglutarate (A-AKG), CLA, ribose, etc may provide additional benefits. Combining creatine with AAKG and/or other potentially ergogenic nutrients may provide additive and/or synergistic effects. In fact, as a vasodilator, Arginine AKG is proving to be a very effective means of transporting creatine and other nutrients into muscle tissue, yielding quicker and more impactful mass gain results.

When is the Best Time to Take Creatine?^90-94 The primary mechanism appears to be related to a carbohydrate and protein stimulated increase in insulin as well as stimulation of protein synthesis by essential amino acids. Since insulin levels enhance creatine uptake, it is my view that once an athlete completes the loading phase, the best time to take creatine is after exercise with a carbohydrate and/or protein supplement.

Should I Cycle On and Off Creatine? There is no evidence that cycling on and off creatine is more or less effective than loading and maintaining creatine. However, the greatest benefits of creatine supplementation appear to be to enhance training adaptations. Therefore, if an athlete wants to cycle creatine, I suggest that they take creatine when they are involved in heavy training and not take it between training phases.

Does Caffeine or Acidity Affect Creatine?
Athletes often ask whether creatine can be taken with caffeine or whether mixing creatine with acidic drinks will degrade creatine. There are a couple of studies that indicate that co-ingesting creatine with large amounts of caffeine may negate some of the performance-enhancing effects of creatine supplementation.^95-98 For this reason, many have warned not to take it with caffeine. However, many of the initial studies mixed creatine in hot coffee or tea to help dissolve the creatine. Additionally, these studies indicated that caffeine did not affect muscle uptake of creatine. Consequently, it is my view that this concern is somewhat overstated. Some have also warned that mixing creatine in acidic solutions (e.g., juices) may degrade creatine to the undesirable creatinine. Yet, the acid level (pH) of coffee (about 4.5), grape juice (about 3), and orange juice (about 2.8) is less acidic than gastrointestinal secretions (about 1) and the acid in the stomach (about 1.5). It is well established that creatine is not degraded through the normal digestive process.⁹⁹ Moreover, a number of creatine studies instructed the subjects to mix creatine with juice and reported ergogenic benefit. Therefore, it is unlikely that mixing creatine in fruit juice would degrade creatine unless you let it sit for several days.

Do Men and Women Respond Differently to Creatine Supplementation?²⁰ In our research, we have found that women typically observe ergogenic benefit following short-term supplementation. However, gains in body mass and fat free mass are generally not as rapid as men. Nevertheless, women do gain strength and muscle mass over time during training.

Is the Weight Gain Water or Muscle? As stated above, creatine supplementation typically promotes gains in body mass and/or fat free mass. Some have suggested that because the gains are fairly rapid, they must be due to fluid retention. Although it is generally accepted that the initial weight gain may promote some water retention, a number of recent studies do not support this concept. In this regard, most studies that have evaluated the effects of creatine supplementation on fluid retention and body composition indicate that although total body water increases, the actual increase appears to be proportional to the weight gained. In this regard, muscle is about 73% water. Therefore, if someone gained 10 pounds of muscle, 7.3 pounds of the weight gain would be water and the percentage of total body water would not be changed. Numerous studies report that long-term creatine increases fat-free mass without an increase in the percent of total body water. Additionally, several studies have found that these gains were accompanied by increased muscle fiber diameter (hypertrophy) and gains in strength.^31,35,36 Consequently, it appears that the weight gain associated with long-term creatine supplementation appears to be muscle mass.

Should Children or Teenagers Take Creatine? Creatine supplementation may be harmful for children or adolescent athletes. However, it should be noted that much less is known about the effects of creatine supplementation in younger individuals. As a result, it is my view that adolescent athletes should only consider taking creatine if the following conditions hold true: On the other hand, several other studies found no effect of low-dose (2 to 3 grams/day), long-term creatine supplementation on exercise capacity. Consequently, it is my view that the best way to increase creatine stores is to follow the aforementioned creatine loading technique followed by ingesting 3 to 5 grams/day thereafter to maintain creatine stores. There is also evidence that coingesting creatine with D-pinitol may augment creatine uptake into muscle. have also been developed in an attempt to optimize creatine availability and/or provide other nutrients that may have health, performance, and/or training benefits. These formulations may also offer a convenient way to provide key nutrients during training. There are limited data suggesting that coingesting creatine with carbohydrate, Research indicates that intense exercise increases anabolic hormone release. Additionally, ingesting carbohydrate and protein or essential amino acids following intense exercise may accelerate glycogen resynthesis as well as promote protein synthesis. About a third of the studies on creatine have evaluated women and/or mixed cohorts of men and women. Several short-term studies on female athletes have revealed limited ergogenic value. This led some researchers to question whether women respond to creatine differently than men. However, a number of recent well-controlled short- and long-term studies in women have reported ergogenic benefits. No study has indicated that

• The athlete is past puberty and is involved in serious/competitive training that may benefit from creatine supplementation;
• The athlete is eating a well-balanced, performance-enhancing diet;
• The athlete and his/her parents understand the potential benefits and side effects of creatine supplementation;
• The athlete's parents approve that their child takes creatine;
• The athlete maintains proper hydration;
• That creatine supplementation can be supervised by the athlete's parents, trainers, coaches, and/or physician;
• That quality supplements are used; and,
• The athlete does not exceed recommended dosages.

If these conditions are met, then I do not see a reason why high school athletes should not be able to take creatine. If these conditions are not met, then I do not believe that creatine supplementation would be appropriate unless prescribed by their physician. To me, this is no different than teaching young athletes' proper training and dietary strategies to optimize performance. Creatine is not a panacea or short cut to athletic success. It can, however, offer some benefits to optimize training of athletes involved in intense exercise in much the same way that ingesting a high-carbohydrate diet, sports drinks, and/or carbohydrate loading can optimize performance of an endurance athlete.

Is Long-Term Creatine Supplementation Safe?^{1,73,74,77,78} One cohort of patients has been monitored since 1981 with no significant side effects.^100,101 Conversely, research has demonstrated a number of potentially helpful clinical uses of creatine in heart patients, infants and patients with creatine synthesis deficiency, patients suffering orthopedic injury, and patients with various neuromuscular diseases. Consequently, all available evidence suggests that creatine supplementation appears to be safe when taken within recommended guidelines.

Is Creatine Supplementation Ethical? Several athletic governing bodies and special interest groups have questioned whether it is ethical for athletes to take creatine as a method of enhancing performance. Their rationale is that since studies indicate that creatine can improve performance and it would be difficult to ingest enough food in the diet to creatine load, that it is unethical to do so. Others argue that if you allow athletes to take creatine, they may be more predisposed to try other dangerous supplements and/or drugs. Still others have attempted to lump creatine in with anabolic steroids and/or banned stimulants and have called for a ban on the use of creatine among athletes. Finally, fresh off of the ban of dietary supplements containing 'fat-burning legends of yesterday', some have called for a ban on the sale of creatine, citing safety concerns. Creatine supplementation is not currently banned by any athletic organization although the NCAA does not allow institutions to provide creatine or other "muscle building" supplements to their athletes. Moreover, although some countries limit how much creatine can be provided per serving in nutritional supplements, I am not aware of any country that has banned the sale of creatine. The International Olympic Committee considered these arguments and ruled that since creatine is readily found in meat and fish, there was no need to ban creatine. Frankly, I don't see creatine loading any different than carbohydrate loading. Many athletes ingest high calorie concentrated carbohydrate drinks in an effort to increase muscle glycogen stores and/or supplement their diet. If carbohydrate loading is not a banned practice, then creatine loading should not be banned. This is particularly true when one considers that creatine supplementation has been reported to decrease the incidence of musculoskeletal injuries, heat stress, provide neuroprotective effects, and/or expedite rehabilitation from injury. It could be argued that not allowing athletes to take creatine may actually increase the risk of athletic competition. Athletes have been using creatine as a nutritional supplement since the mid 1960's. Widespread use as a dietary supplement began in the early 1990's. No side effects directly attributable to creatine supplementation have been reported in the scientific literature. Nevertheless, there are some concerns about the long-term side effects of creatine supplementation. Over the last few years, a number of researchers have begun to report long-term safety data on creatine supplementation. So far, no long-term side effects have been observed in athletes (up to 5 years), infants with creatine synthesis deficiency (up to 3 years), or in patient populations (up to 5 years).