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Can Creatine Safely Build Muscle?
Creatine’s safety has been brought into question during a recent lawsuit. Matt Samuels claims that the Prince George’s County Board of Education and a Roosevelt lacrosse coach were negligent and committed a breach of duty when the lacrosse coach gave Samuels creatine sports drinks during the 2004 season. Just before the playoffs, Samuels was hospitalized and linked the problems with the increased creatine use (http://www.washingtonpost.com/wpdyn/content/article/2005/08/31/AR2005083102237.html). Several concerns have been raised about the safety and effectiveness of creatine in today’s society.
The human body receives creatine (methyl guanidine-acetic acid) from diet and by synthesizing arginine, glycine, and methionine in the liver and kidney’s. Red meat and fish are two excellent food sources for creatine (http://www.mothernature.com/Library/B ookshelf/Books/23/24.cfm). The body produces about 2 grams of creatine per day. An average 160 pound male will have about 140 grams of creatine in his body where 95% is stored in the various muscles. Normally the body maintains 3.5 grams of creatine per pound of muscle, but the human muscle is actually able to hold up to 5 grams per pound (http://www.absolute-creatine.com/creatine.htm).
After the creatine supplement is consumed and absorbed, the blood vessels carry the creatine to the different muscles. Now, creatine is converted into creatine phosphate. During exercise, the muscles use adenosine triphosphate (ATP) as the energy source. ATP is utilized during short and quick activities like weight lifting. ATP is then broken down into ADP and a phosphate group, thus releasing the energy the muscle needs. Only about 5-10 seconds of ATP energy reserves are present in your muscles at any given time.
When you run out of ATP, the body converts Glucose (carbohydrates) into ATP, but this takes 20 seconds. In the mean time, the body will utilize the extra phosphate groups by binding them to creatine to serve as an additional source of fuel for the muscles. Creatine can be converted into ATP at an extremely fast rate. After the creatine phosphate stores are depleted, the muscle no longer has any energy left to work (http://www.absolute-creatine.com/creatine.htm). By adding creatine to a diet, one can increase the amount of creatine reserves and receive an additional period of energy.
By just eating a normal diet, you are not maximizing the potential amount of creatine phosphate you can store. After ingesting creatine, the creation of additional creatine phosphate stores in your muscles is possible.
The most common effect of creatine supplementation will be experienced during weight lifting. The extra stores of creatine phosphate will allow you to get an additional 1-3 repetitions. The more creatine phosphate that is in the muscles, the stronger the muscles are going to be. This translates into being able to lift more weight. By putting more stress on the muscle fibers, the muscles are able to build more muscle faster (http://www.b uilding-muscle101.com/how-does-creatine-work.html).
There are three main forms of creatine supplementation: creatine monohydrate, creatine phosphate, and creatine citrate.
Creatine monohydrate is by far the most common form of creatine found in supplementation. It is composed of 88% creatine and 22% water. Most research studies use this form of creatine because it is the most widely used form of creatine.
Creatine phosphate is another form that is composed of 62.3% creatine and 37.7% phosphate. The thinking behind this form is that it is the form that your body uses to actually power itself, since creatine on its own will not work. It has to be bounded to a phosphate group. One disadvantage to this form is that you get only 623 milligrams of creatine per gram taken.
Creatine citrate is yet another form that is supposed to be much more water soluble and thus is easier to mix with water and taste better. However, there is only about 400 milligrams of creatine per gram of creatine citrate.
If you take 5 grams of:
· Creatine Monohydrate = 4.40 g of creatine
· Creatine Phosphate = 3.12 g of creatine
· Creatine Citrate = 2 g of creatine
However, not all the different forms of creatine have the same absorption rate into the muscles. Creatine citrate is supposed of have an absorption rate of 90%, while creatine monohydrate is only absorbed at a rate of 40%. Thus, creatine citrate actually lets your muscles get more creatine (http://www.absolute-creatine.com/2.htm).
Creatine is a relatively new performance enhancing supplement that first became popular in 1992. There are no long term studies on this supplement because it is so new. The recommended doses vary from 5-25 grams a day depending on the type and manufacturer. Dr. Ara DerMarderosian states that it is not a matter if creatine is safe or not (it is already found naturally in the body), but what the potential side effects could be for taking an increased dose for a long period of time. (http://www.mothernature.com/ Library/B okshelf/Books/23/24.cfm).
Other potential adverse side effects can include kidney stones, bloating, and muscle aches due to lactic acid build up. As well, there the leading perceived risk among highschoolers involves dehydration. There are also questions as to whether it affects the heart, since it is a muscle as well (http://www.bodybuildingforyou.com/creatine/creatine-side-effects.htm).
In 1998, a Houston Astros player died from dehydration, kidney stones, and transient kidney damage. These are all side effects of creatine use, which the player had been on. (http://www.rice.edu/~jenky/sports/creatine.html). As well in 1997, three collegiate wrestlers, who were using creatine, died within a very short time span. The media linked these deaths to creatine use. However, NCAA investigators never made such a claim and the media sensationalized the story. However, neither of these alleged creatine deaths were scientifically linked to creatine caused deaths (http://www.fuelingtactics.com/9 8timeline1.htm).
In one study, participants exercised one side of their body twice a week while taking creatine and twice a week on the opposite side of the body while taking a placebo. There were two groups: one composed of women and one of men. The creatine and placebo were consumed after the workout. The participants were given either a 200 mg dose of creatine or a placebo after the workouts. Elbow flexors and knee extensors thickness, lean tissue mass, bone mass, and single-limb bench and leg press one-repetition maximums were measured after 6 weeks. The creatine group showed an increase in muscle size on the days that creatine was used. Males that took the creatine experienced the biggest increase in lean tissue mass, while there was no difference for the females. As well, the maximum bench press increased for the both women and men taking creatine. However, bone mass increased in both creatine and non-creatine groups (Chilibeck al., 2004).
This second study looked at the effects of creatine monohydrate in young soccer players ranging in age (16.6 +/- 1.9 years). Two groups were created: one group received 3, 10 gram creatine doses, for 7 days (21 days total) and the control group received a placebo for the same duration. The soccer skills were compared before and after the supplementation. After 21 days, the players could on average jump 5.9 cm higher, dribble 2.8 seconds faster, and perform a short sprint in 2.2 seconds from 2.7 seconds. The supplementation of creatine monohydrate improved specific soccer skills (Ostojic, 2004).
Finally, one report combined 16 different creatine and weight lifting studies into one analysis of creatine's effectiveness. The maximum lifted weight difference between the placebo group and the creatine groups differed by 15.1 pounds. The creatine group was also able to bench press 21 pounds more than the placebo group. However, there was no difference in cycle ergometer or isokinetic dynamometer performance.
Here is one chart that compares 8 out of 16 different studies:
Taken from Dempsey et al., 2002
The creatine group was able to lift more weight than the placebo group in every study (Dempsey et al., 2002).
Potential side effects studies
This study looked at the following potential side effects due to creatine supplementation: fatigue, cramping, and musculoskeletal injury. The study looked at the perceptions of athletes’ physical health over a 19 week period. 15.75 grams of creatine was given to one group of Division 1A football players for 5-7 days and then a dose between 5-10 grams for the rest of the duration. All athletes received the creatine with carbohydrate supplements after practices and filled out a fatigue inventory every week. The scientist found that the athletes that took creatine had significantly less heart and lung fatigue, a more positive attitude towards practice, and overall felt stronger than non creatine users. Those players that took creatine showed no adverse side effects or illness due to creatine (Kreider et al., 2002).
Furthermore, another similar study looked at specific cramping or injury rates during an 18 week period of collegiate football players who did and did not take creatine. The creatine group took 20-30 grams of creatine for the first 5-7 days and 5-10 grams a day after that. The results showed that creatine group’s cramping, heat/dehydration, muscle tightness, muscle pulls/strains, non-contact joint injuries, contact injuries, illness, number of missed practices due to injury and total injuries/missed practices were either lower or proportional to the non-creatine group. The creatine group was thus a healthier overall group. The supplementation of creatine did not have any adverse physical effects on the athletes (Greenwood et al., 2002).
Finally, there have been several studies about the effects of creatine on renal (kidney) function. After the body ingests creatine and uses it, it is broken down by nonenzymatic dehydration to creatinine. Measuring the levels of creatinine is a good barometer to see how well the kidney is dealing with the extra creatine. These scientists measured urine samples to see how much creatinine was left in the blood after going through a normal course creatine. The normal course consisted of significant amounts of creatine for 4-5 days. They found that there was no significant increase in creatinine levels after increased creatine intake. Interestingly, they did not find an increase in creatine levels. This leaves open the possibility that longer term creatine use can increase the body’s creatine levels they said (Haghighi et al., 2003).
There are very few journal articles looking at creatine and the effects of dehydration. The potential risk states that since the cells absorb some water due to the increase use in creatine, there will be less water left over the body and dehydration can occur much faster than one would thin and thus pose a potential risk. This risk is especially high in athletes like wrestlers who have to make specific weight limits and frequently try to loose as much water weight as possible. The only article that came close to talking about the effects of creatine and water compares the amount of water in the body before and after creatine using a DEXA scan. The scan showed no difference in the amount of water between the two scans. This could either mean that the creatine is not pulling the water into the muscle cells or that it is pulling the water into the cells and that there is not enough water in the rest of the body. Thus, the lack of extracelluar water could pose kidney risk (Haghighi et al., 2003).
The websites I found and used in my creatine web research were all informational sites that did not sell creatine. This made the websites appear more honest as there were no conflicts of interest. For example Absolute-creatine.com is composed of personal trainers, gym rats, computer geeks and other “health nuts.” On there website they claim that they aren’t doctors and this is the knowledge that they know and live by. Only one of these websites quoted college professors and vaguely linked what they said about creatine to actual scientific studies. These websites had a “word of mouth” feeling to them in that they might have sounded scientific, but the information is comparable to asking an informed friend.
The information I found on the internet was accurate in its creatine descriptions. The biological role that creatine plays in the body was just as accurate on the websites as it was in the journal articles. As well, the effectiveness didn’t differ between the websites and journal articles either. Creatine has been proven to help people grow more muscle and even increase actual athletic skills. Unfortunately, creatine is just too new of a drug to have any long term studies that are able to determine if there are any major risks. However, in the short run creatine does not appear to have any adverse health effects. All of the anecdotal evidence regarding creatine’s dangerous effects is unconfirmed in journal articles and should be disregarded.
Kreider, Greenwood, Melton, Rasmussen, Cantler, Milner, and Almada. (2002). Creatine Supplementation during training/competition does not Increase Perceptions of Fatigue or adversely affects Health Status. Exercise & Sport Nutrition Lab34:S146.
Chilibeck, Stride, Farthing, and Burke. (2004). Effect of Creatine Ingestion after Exercise on Muscle Thickness in Males and Females. Medicine & Science in Sports & Exercise. 36(10):1781-1788.
Dempsey, Mazzone, and Meurer. (2002). Does oral creatine supplementation improve strength? A meta-analysis. The Journal of Family Practice. Vol. 51, No. 11.
Haghighi, M 1; Taylor, W C. (2003).Effects of oral Creatine on Renal Function Weightlifting. Medicine & Science in Sports & Exercise: 35(5) Supplement 1:S314/.
Ostojic SM. (2004). Creatine supplementation in young soccer players. Int J Sport Nutr
Exerc Metab. 14(1):95-103.
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