I will place studies on Creatine Mono in here, for any one that doubts it or thinks it is unhealthy to use.
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I will place studies on Creatine Mono in here, for any one that doubts it or thinks it is unhealthy to use.
Similar Bodybuilding Threads:
While creatine has many applications to individuals of all gender, age, mental and physical abilities, this paper is written for young, healthy men who are active in sports or exercise. I have not taken into account the numerous studies done for children, the elderly and middle aged, or women when writing this article. All data and studies used in this paper are in reference to healthy men between the ages of 18-40, who participate in physical activity several times a week, unless otherwise stated.
Furthermore, I am neither a doctor, nor a pharmacologist. The information, views, and advice contained within this paper are for educational purposes only. Do not attempt any exercise plan, diet plan, or radical lifestyle change without first consulting with a physician. The material in this paper should not be construed for medical advice. Neither creatine, nor the methods of supplementation discussed within should be used to treat any condition or disease, unless instructed by a doctor.
The compound creatine has been hyped by supplement companies and demonized by the media, and without proper study in the field of supplement pharmacology, Primary Care physicians cannot offer any relevant information to the consumer. It is not surprising that there is much confusion over the safety and effects of creatine.
Creatine is a naturally occurring substance in human and animal bodies. It is synthesized and consumed on a daily basis (the human liver can combine the amino acids Arginine, Glycine, and Methionine to synthesize creatine). The average 160 lb (72.5 kg) person stores approx. 120 grams of creatine in their body. 95-98% of that creatine is contained within muscle tissue, while the rest is stored within other body organs (including brain, heart and liver).
Creatine works by replenishing ATP. ATP (adenosine tri-phosphate) is an energy-containing compound. The body can break ATP into ADP (adenosine di-phosphate) and inorganic phosphate. This reaction releases energy, which can be used by the body to fuel explosive, short burst of strength. The metabolism of carbohydrates and fats take longer to convert into a useable energy source, so ATP is the most used energy source during these high intensity movements. There is only enough ATP for 10-15 seconds of maximum exertion, however, and so the problem arises as to how to free up more energy. ADP is itself useless as a source of energy, until it regains a phosphate atom. Creatine phosphate (CP), the form of creatine found mostly in muscles, reacts with ADP. The phosphate is freed from creatine and bonds with ADP to create ATP.
This purpose of creatine has been known for some time, however the benefits or downfalls of exogenous supplementation of creatine on physical performance, especially in the area of sports and exercise, has long been glorified, but up until the past few years never substantiated with hard science. The ignorance of health care professionals has obfuscated the subject of creatine supplementation, and for many people the only information they hear is the half-truths, propaganda, and lies of the media and supplement companies.
Many of the claims put forth about creatine’s safety focus on the idea that it may harm the kidneys and liver. This is false. Creatine does not harm the liver5, 24, 49, 80, or the kidneys1, 5, 8, 24, 49, 64, 80. Some of these claims stem from the idea that creatinine levels are increased with creatine supplementation (creatinine being a byproduct of renal failure). Creatinine, while sometimes slightly elevated, is always within normal and safe levels when creatine is used according to recommended guidelines2, 24, 29, 49, 64, 71, 80. A deleterious effect on cholesterol and lipid values is another popular argument by critics of the supplement. While not studied as much as other areas of safety, limited studies have shown no effect2, 5, or a positive effect of cholesterol4. Blood values during creatine supplementation have also been shown to be normal19, 49, 71, 80, as well as effects on mood51.
A common complaint among sports coaches and players is that creatine may increase injury rates. Some people have claimed this is due to increased musculoskeletal stiffness. No studies have reported any signs of increased injury with concomitant creatine use, and at least one has even tested the claim and shown that there are no negative musculoskeletal changes with creatine use75.
On the other side of the spectrum, there are many claims of performance enhancement with creatine use. Increased muscle mass2, 19, 26, 35, 37, 61, 71 is one proven effect of creatine use. Enhanced anaerobic capacity and strength has shown to be beneficially effected6, 9, 16, 19, 26, 27, 28, 33, 34, 37, 40, 41, 46, 51, 52, 56, 59, 60, 61, 65, 86 in all but one68 study. The overwhelming data supporting increased strength, and to a lesser degree muscle mass, makes creatine a wonder supplement. There are, however, many more benefits to creatine supplementation that puts this supplement a step above all others. Conflicting data shows that creatine may9, 10, 23, 69, 70 increase aerobic performance, or have no effect28, 50, 67, even though body mass increases. The fact that aerobic performance increases are possible in spite of increased body mass means that individuals training for endurance, speed and strength may benefit from creatine without risking negative changes in performance. Sprinting, studied in its numerous forms, also shows mixed results with regards to creatine. While some show no effect12, 15, 20, 42, 43, 53, 56, 63, 73 the majority of studies have shown marked increases in performance13, 19, 25, 28, 36, 38, 44, 57, 58, 62, 66, 79, 82. Isometric strength increases22 and isometric strength endurance21, anticatabolic47 and antioxidant31 properties, jumping improvements59, 75, exercise recovery77, 78, performance in hot conditions79, and time to neuromuscular fatigue81 are some of the other strength and endurance related benefits observed in some of the studies. These benefits also come with another bonus: body fat percentage has been shown to not change2, 61, 71 or decrease51 in several studies that looked at body composition.
Creatine may also assist injured individuals who are recovering from major injuries. After non-use and atrophy, creatine may increase GLUT-4 protein concentration and translocation at cell membranes30 as well as muscular performance recovery55. The intracellular water retention creatine creates11, 26 may also help maintain an anabolic environment and allow extra nutrient and glycogen to be stored in the recovering muscle. Even though creatine has been show in some studies to have no effect on hormone levels45, 49, one study studying Growth Hormone (GH) specifically has shown an increase (within high normal levels) of GH with creatine use. GH has anabolic properties, as well as healing properties, and this may be another benefit of using creatine to help speed recovery from an injury. Another benefit to individuals recovering from injury, and those that aren't, is that creatine may stimulate satellite cell differentiation32, which may increase muscle size and help heal injuries.
Creatine is also synergistic with many other substances. Creatine has shown positive effects with pyruvate3, whey protein17, caffeine18, carbohydrates34, 52, 74, l-glutamine37, and magnesium72. Creatine stacked with HMB has produced good results48, as well as no results14.
The dosing of creatine has also come into suspect since several animal studies with ultra high doses of creatine produced creatine receptor down regulation after several weeks of use. Considering these studies used extremely high doses of creatine, and with at least one study showing no down regulation with continued use in humans39, it appears now that cycling creatine is not needed to keep your gains. Loading creatine in several small portions throughout the day has given the best results and shown the most saturation of the muscle amino acid pool with creatine76, and may be the best way to take it during the loading phase.
Hopefully the stigma of creatine being a deadly drug that destroys organs, increases injuries and increases fat will go away now that there are so many studies showing the positive effects and lack of negative effects with supplementation.
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Beth Lulinski, M.S., R.D.
Creatine is marketed as "nature's muscle builder" and "the most legitimate sports supplement around." Professional and amateur athletes alike are gobbling up this alleged ergogenic aid, hoping to increase their strength and performance. Creatine supplementation is claimed to increase muscle power by playing a role in the transfer of energy to help the muscle contract. Supplement labels state that "creatine is converted to phosphocreatine, which is important for short energy bursts such as sprinting and weight lifting" and that "depletion of phosphocreatine can result in muscle fatigue and fading muscle power." Claims are also made that supplementation increases muscle body mass.
Health-food stores sell creatine supplements in capsule, chewable, and powdered form, the most popular being the powder. One teaspoon of powder contains 5 grams (g) of creatine monohydrate. The recommended daily dose is 1-2 teaspoons dissolved in 8 ounces of water or sweetened beverage. Manufacturers and distributors suggest a five- to seven-day loading phase with intake of 10-20 g (2-4 scoops) daily to fill up the muscle. The maintenance phase of 5-10 g/day is recommended before and/or immediately following a workout. This protocol is claimed to increase creatine muscle stores by 20-50%.
Role In Muscle Contraction
To meet the demands of a high-intensity exercise, such as a sprint, muscles derive their energy from a series of reactions involving adenosine triphosphate (ATP), phosphocreatine (PCr), adenosine diphosphate (ADP), and creatine. ATP, the amount of which is relatively constant, provides energy when it releases a phosphate molecule and becomes ADP. ATP is regenerated when PCr donates a phosphate molecule that combines with ADP. Stored PCr can fuel the first 4-5 seconds of a sprint, but another fuel source must provide the energy to sustain the activity. Creatine supplements increase the storage of PCr, thus making more ATP available to fuel the working muscles and enable them to work harder before becoming fatigued .
The body's pool of creatine can be replenished either from food (or supplements) or through synthesis from precursor amino acids. Dietary sources include beef, tuna, cod, salmon, herring, and pork . The normal dietary intake of creatine is 1-2 g/day, although vegetarians may consume less [3,4]. Dietary creatine is absorbed from the intestines into the bloodstream. If the dietary supply is limited, creatine can be synthesized from the body stores of the amino acids glycine, arginine, and methionine. The kidneys use glycine and arginine to make guanidinoacetate, which the liver methylates to form creatine , which is transported to the muscle cells for storage. It is also stored in the kidneys, sperm cells, and brain tissue .
The maximum amount of creatine the body can store is about 0.3 gram per kilogram of body weight . The creatine content of skeletal (voluntary) muscles averages 125 millimoles per kilogram of dry matter (mmol/kg/dm) and ranges from about 60 to 160 mmol/kg/dm. Approximately 60% of muscle creatine is in the form of PCr. Human muscle seems to have an upper limit of creatine storage of 150 to 160 mmol/kg/dm. Athletes with high creatine stores don't appear to benefit from supplementation, whereas individuals with the lowest levels, such as vegetarians, have the most pronounced increases following supplementation. Without supplementation, the body can replenish muscle creatine at the rate of about 2 g/day .
Although creatine is a natural component of food, the amount of food required to supersaturate the muscle with PCr may not be feasible. For example, it could require 22 pounds of meat daily . If creatine monohydrate is proven to be a safe and effective ergogenic aid, creatine supplementation may be the simplest way to increasing muscle stores. It may be beneficial to avoid caffeine if taking creatine supplements. One study showed that caffeine diminished strength gains seen with creatine use .
Evidence Supporting Use
Several studies support the use of creatine supplementation for enhancing activities that require short periods of high-intensity power and strength. These include weightlifting, sprinting, and rowing.
* One study demonstrated that daily supplementation with 5 g of creatine monohydrate increased the intracellular creatine and PCr content of quadriceps muscle in 17 human subjects. Those with the lowest initial total creatine content had the greatest increase. In addition, exercise enhanced creatine uptake in muscle. No adverse effects were reported .
* Another study found that one week of creatine supplementation at 25 g/day enhanced muscular performance during repeated sets of bench press and jump squat exercise. Creatine supplementation appeared to allow the subjects to complete their workouts at a higher intensity. The researchers concluded that, over time, working at higher intensities may provide a more intense training stimulus and improved muscular adaptations .
* Another study demonstrated that females receiving 4 days of high-dose creatine intake (20 g/day) followed by low-dose creatine intake (5 g/day) during 10 weeks of resistance training (3hours/week) increased muscle PCr concentrations by 6%. Also, maximal strength of the muscle groups trained increased by 20-25%, maximal intermittent exercise capacity of the arm flexors increased by 10-25% and fat-free mass increased by 60% .
* A double-blind study provided 20 g/day of creatine monohydrate for 5 days to qualified sprinters and jumpers who performed 45 seconds of continuous jumping and 60 seconds of continuous treadmill running. Supplementation enhanced performance in the jumping test by 7% for the first 15 seconds and 12% for the next 15 seconds, but there was no difference for the final 15 seconds. There was a 13% improvement in the time of intensive running to exhaustion .
* Another double-blind study supplemented with 18.75 g/day of creatine monohydrate for 5 days prior to high-intensity intermittent work to exhaustion, and then 2.25 g/day during testing. The workouts consisted of cycling to exhaustion using several protocols: (a) nonstop, (b) 60 seconds work/120 seconds rest, (c) 20 seconds work/40 seconds rest, and (d) 10 seconds work/20 seconds rest. Creatine supplementation significantly increased the total work time for all four protocols .
* Another study tested male subjects performing two bouts of 30 second isokinetic cycling before and after ingesting 20 g creatine monohydrate daily for 5 days. Work production improved about 4%. Cumulative increases in both peak and total work production over the two exercise bouts were positively correlated with the increase in muscle creatine .
* A 12-week placebo-controlled study of 19 weightlifters in their mid-twenties found that the creatine group could lift more weight and had greater increases in fat-free mass and muscle-fiber size than did the placebo group. The researchers thought that the creatine let the athletes who used it train harder .
* Three additional studies suggest that creatine supplementation may not be beneficial for running velocity, sprint swimming performance, or a maximal cycling effort . Short bouts of repeated anaerobic activity have shown some potential benefits with creatine supplementation use in a laboratory setting. However, creatine supplementation has not been shown to enhance single-event performance such as stationary cycling [16-19]. Taken together, these studies do not support creatine supplementation to enhance aerobic activities such as distance running.
Other areas of research include therapeutic uses of creatine to help patients with muscle wasting caused by disease states such as muscular dystrophy and amyotrophic lateral sclerosis (ALS). Small-scale preliminary studies show some gains in strength may be possible for these patients, which could improve their quality of life. One study of 81 patients with various neurologic diseases found that giving 10 g/day of creatine for five days, followed by 5 grams for another week, increases their muscle strength by about 10% . Large-scale studies should be done before recommendations are made to such patients.
Creatine supplementation often causes weight gain that can be mistaken for increase in muscle mass. Increasing intracellular creatine may cause an osmotic influx of water into the cell because creatine is an osmotically active substance . It is possible that the weight gained is water retention and not increased muscle. The retention of water may be connected to reports of muscle cramps, dehydration, and heat intolerance when taking creatine supplements. It would be prudent to encourage proper hydration for creatine users. Further research is needed to investigate these and other possible side effects.
Creatine is classified as a "dietary supplement" under the 1994 Dietary Supplement Health and Education Act and is available without a prescription. Creatine is not subjected to FDA testing, and the purity and hygienic condition of commercial creatine products may be questionable . A 1998 FDA report lists 32 adverse creatine-associated events that had been reported to FDA. These include seizure, vomiting, diarrhea, anxiety, myopathy, cardiac arrhythmia, deep vein thromboses and death. However, there is no certainty that a reported adverse event can be attributed to a particular product . A recent survey of 28 male baseball players and 24 male football players, ages 18 to 23, found that 16 (31%) experienced diarrhea, 13 (25%) experienced muscle cramps, 7 (13%) reported unwanted weight gain, 7 (13%) reported dehydration, and 12 reported various other adverse effects .
* Jenkins, MA. Creatine supplementation in athletes: Review
* Creatine is the object of intensive research. To keep current, use the links below to visit the abstracts on PubMed and click on "Related Articles" when you arrive.
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Thanks Allstar for the studies!
Because the text is so large, I'd edit it to the hypothesis, abstract and conclusive data. Also remove the references; keep them on hand if Tim, IS, Braaq, etc. are interested in responsibility. Also, add subtitles to title each topic...that'd be great bro. Bookmarked.