CREATINE: OVERVIEW One Michel Eugène Chevreul discovered the component now known as creatine in skeletal muscle in 1832. Creatine is an organic acid that helps supply cells with energy, this is important for sportsmen and women as the cells primarily involved are found in muscle tissue. This energy is attained by increasing the construction of adenosine triphosphate or ATP. Creatine is produced naturally in our bodies from amino acids, breakdown which occurs mainly in the liver. The creatine is then transported via the vessels to our muscles, with 90-95% of all total creatine being located in the skeletal muscles. As creatine is manufactured by the body from the amino acids: L-methionine, L-arginine and glycine it is not an “essential” nutrient, this being the case 50% of all our stored creatine comes from food, and meat in particular, studies show that vegetarians have a much lower creatine store within the skeletal muscles as non-vegetarians. Now this doesn’t mean that vegetarians should supplement actual creatine, although that is an option. A more natural method of lifting the creatine levels would be to supplement foods that contain the above mentioned amino acids thus allowing the body to synthesize the required creatine.
Here’s a quick table of creatine content in certain foods: Food
Creatine Content g/kg
Herring
5-10
Salmon
4.5
Tuna
4
Cod
3
Plaice
2
Pork
5
Beef
4.5
Cranberries
0.9
Carrots
0.3
The two main enzymes for synthesis of creatine are GATM and GAMT, persons with shortages in the creatine biosynthetic pathway suffer from musculoskeletal and severe neurological symptoms. Creatine that has been synthesized is transported to high demand tissues, in PT’s and clients this happens to be the skeletal muscles, however the brain also needs some of that juice. The ATP already found in the muscle (2-5mM) allows contraction of up to 8-10 seconds before requiring replenishing, the ATP/PCr system then swiftly uses ADP to reform ATP with the usage of PCr (phosphocreatine) with the enzyme CK creatine kinase. Creatine supplementation has the ability to increase muscle storage of PCr which in theory will help the cycle of replenishing ATP from ADP to meet the demands placed upon it.
This leads us nicely to the topic of creatine supplementation, creatine supplements are aids to increase athletic performance, in particular those involved with high intensity. Research showed that creatine was an energy for muscles from way back, but it did not become popular till 1992 as a performance enhancer. HISTORY Let’s have a little look at history, Willey Glover Denis in 1912 at Harvard discovered that ingesting creatine effects the creatine content in muscles significantly. After this discovery researchers in the late 20’s discovered creatine phosphate, coming to the conclusion that that this plays a key role in the metabolism of skeletal muscle. During the 1992 Barcelona Olympics a report that the gold medallist Linford Christie came about that he had used creatine supplementation before the games, this was also true of Colin Jackson and Sally Gunnell. By the time 1993 rolled in EAS (Experimental and Applied Sciences) popped a supplement on the market in the UK called “Phosphagen”. The research that was carried out showing that creatine supplementation taken alongside high GI carbohydrates increased the muscle storage of creatine. As time passed many companies have brought out creatine products each having their own claims that theirs is superior. THE SCIENCE Scientific evidence has shown that creatine supplementation taken in the short term can improve all-out power by up to 5% and performance in ANAEROBIC repetition, which means short bursts of activity followed by rest periods, studies vary showing that the improvement is anywhere between 5% and 15% in this repetition. However whilst certain studies do show this, other studies have found no beneficial difference at all. Studies involving endurance sports such as marathon etc. have been less effective, this is mainly caused by the lack of rest period in between activity where re-synthesis of ATP can take place, even though these same studies showed that creatine increased phosphocreatine in the muscle by 20% it still lead to no significant difference in performance for endurance activities. However the proof is very strong for those involved with short bouts of activity. Those who take creatine will have realised that there is a gain in weight, with some gaining 1kg (2.2lbs) a week. Most studies believe this is caused by water
retention with cells mainly found in the skeletal tissue. This has been challenged recently with studies showing that creatine grows activity within muscle satellite cells by increasing the number of myonuclei that these cells give to help in the repair stages of muscle damage (commonly caused by exercise), creatine appears to increase the myogenic transcription factor MRF4 making this possible, therefore these satellite cells are what make muscle hypertrophy conceivable. Other studies show that fat loss is less achievable when supplementing with creatine, the researchers in this case used a placebo control group which lost body fat after training but didn’t increase 1RM, whilst the creatine group increased in weight with no BF% loss but had an increase of 1RM. Creatine as of 05/12/2013, is not banned in the majority of sport. Although certain educational teams are not allowed to supply their players with creatine, the players are still free to purchase and use as they see fit. INTERESTING EFFECTS Serum myostatin has been shown to decrease when resistance training is combined with creatine supplementation over an 8 week period against just resistance training and a control group which had no resistance training and no creatine supplementation. The creatine and resistance groups showed myostatin levels of 98ng/ml compared to 110ng/ml of the resistance only group and 120ng/ml of the control. For those who are not sure of what myostatin is, it is basically a protein that causes catabolism on skeletal muscle, this is to help limit skeletal muscle, and therefore a way of decreasing this within our bodies will have in theory beneficial effects on the skeletal muscles. Most Olympic athletes have been found to have lower level of myostatin.
A cow born with myostatin mutation:
Creatine has also been shown to increase dihydrotestosterone (DHT), supplementation appears to increase DHT by 56% after a 7day loading cycle of creatine monohydrate remaining 40% higher within the maintenance stage. Whilst one study did find that creatine increased testosterone this has never been reproduced in other similar studies and therefore creatine cannot be seen as an adequate method of increasing testosterone. Insulin-like growth factor-1 (IGF-1) appears to increase by 15% with creatine supplementation against a placebo group after an 8 week period, however further studies are required to verify this. Cognitive performance has been shown to increase in both cognitive functioning and memory in a double blind study, comparing vegetarians taking creatine and vegetarians taking a placebo. More study is required to see if the effects can be reproduced using non-vegetarians who may have adequate creatine stores from meat. CREATINE ITSELF Monohydrate The most common form of creatine supplementation is creation monohydrate and creatine ethyl ester. Many methods of ingestion currently exist, the powder form being the oldest which you mix with a juice or drink, and capsule forms. Once creatine becomes ingested into the body it becomes highly bioavailable. Conventionally creatine consumption should be taken alongside a high GI carbohydrate as research suggests that this is the best way for good creatine retention. Serum and plasma creatine concentrations in healthy adults range from 212mg/l, with a single 5g dosage of creatine monohydrate causing a peak of 120mg/l 1-3 hours post ingestion. As creatine has a short half-life of around 38 hours, smaller dosages are needed throughout the day to maintain high serum/plasma levels. Most who choose the monohydrate take 2-5g daily, this is commonly after a “loading phase� of around 10g for 4-7 days, however these dosages vary greatly from person to person, we would recommend following manufacturers advice. Buffered Kre-Alkalyn is a buffered form of creatine monohydrate, the claims being that it can cause greater creatine retention at a lower dosage and with lower side
effects. However most research suggests that this form has no difference in effect compared with monohydrate. Any research that says otherwise has been found to be biased and/or made by the manufacturer. Creatine ethyl ester (CEE) CEE is the second most common form of creatine on the market against monohydrate, it has been hyped to have higher absorption and a longer halflife than that of monohydrate. However as of now no peer reviewed studies have shown to back up these claims. The ISSN have shown that the added ethyl group actually reduces effectiveness of the supplement against the monohydrate version. Creatine hydrochloride Another version of creatine that has come with much hype, a study that was conducted by a manufacturer of the product has shown that it is 59% more soluble in water then monohydrate and therefore dosages can be much lower. More study is required to verify the claims made from this study. Creatine nitrate and Creatine gluconate You may run across these in your travels for a creatine supplement, however as of yet no studies show any significant benefits over creatine monohydrate. UNWANTED EFFECTS Currently research shows that creatine supplementation in healthy individuals is perfectly safe, those with kidney problems and liver problems should avoid creatine supplementation however. There are risks of renal dysfunction occurring, and those supplementing with creatine should keep that in mind. In healthy individuals, bloods have come back normal even after 11 weeks of supplementation. It has been found that creatine supplementation actually increased the life span of mice, these are yet to be backed by human trials however. Creatine may cause an increase in the speed of growth of polycystic kidney disease (PKD), however these reports need to be verified, side effects of creatine supplementation have been anecdotally and scientifically contested. I recommend that you keep to creatine monohydrate and follow the instructions unless you are experienced. Creatine is probably the most effective non-hormonal product for those involved in resistance training, and in a world full of terribly hyped products, CREATINE MONOHYDRATE truly is KING!
Creatine Timing Tip: 1. Creatine monohydrate 2-5g is best taken post-workout in a carbohydrate rich drink such as pure fruit juice. 2. 1-5g can be taken pre-workout also with beta-alanine as a bonus.
REFERENCES/BIBLIOGRAPHY Bender, A.; Beckers, J.; Schneider, I.; Hölter, S.M.; Haack, T.; Ruthsatz, T.; Vogt-Weisenhorn, D.M.; Becker, L. et al. (2008). Creatine improves health and survival of mice. Neurobiology of Aging 29 (9). Buford, Thomas W; Kreider, Richard B; Stout, Jeffrey R; Greenwood, Mike; Campbell, Bill; Spano, Marie; Ziegenfuss, Tim; Lopez, Hector et al. (2007). International Society of Sports Nutrition position stand: Creatine supplementation and exercise. Journal of the International Society of Sports Nutrition 4: 6. Chen, J.; Wang, M.; Kong, Y.; Ma, H.; Zou, S. (2011). Comparison of the novel compounds creatine and pyruvateon lipid and protein metabolism in broiler chickens. Animal 5 (7): 1082–9. Chilibeck, Philip D.; Magnus, Charlene; Anderson, Matthew (2007). Effect of in-season creatine supplementation on body composition and performance in rugby union football players. Applied Physiology, Nutrition, and Metabolism 32 (6). Dalbo VJ, Roberts MD, Stout JR, Kerksick CM (July 2008). Putting to rest the myth of creatine supplementation leading to muscle cramps and dehydration. British Journal of Sports Medicine 42 (7) Deldicque, Louise; Décombaz, Jacques; Zbinden Foncea, Hermann; Vuichoud, Jacques; Poortmans, Jacques R.; Francaux, Marc (2007). Kinetics of creatine ingested as a food ingredient. European Journal of Applied Physiology 102 (2). Hespel, P; Eijnde, BO; Derave, W; Richter, EA (2001). Creatine supplementation: Exploring the role of the creatine kinase/phosphocreatine system in human muscle. Canadian journal of applied physiology = Revue canadienne de physiologie appliquee. 26. Kamber, Matthias; Koster, Markus; Kreis, Roland; Walker, Gianni; Boesch, Chris; Hoppeler, Hans (1999). Creatine supplementation—Part I: Performance, clinical chemistry, and muscle volume. Medicine & Science in Sports & Exercise 31 (12). Lyoo, I. K.; Yoon, S.; Kim, T. S.; Hwang, J.; Kim, J. E.; Won, W.; Bae, S.; Renshaw, P. F. (2012). A Randomized, Double-Blind Placebo-Controlled Trial of Oral Creatine Monohydrate Augmentation for Enhanced Response to a Selective Serotonin Reuptake Inhibitor in Women with Major Depressive Disorder. American Journal of Psychiatry 169 (9). McMorris T, Mielcarz G, Harris RC, Swain JP, Howard A (September 2007). Creatine supplementation and cognitive performance in elderly individuals. Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition 14 (5).
Rawson ES, Lieberman HR, Walsh TM, Zuber SM, Harhart JM, Matthews TC (September 2008). Creatine supplementation does not improve cognitive function in young adults. Physiology & Behavior 95 (1–2). Saremi, A.; Gharakhanloo, R.; Sharghi, S.; Gharaati, M.R.; Larijani, B.; Omidfar, K. (2010). Effects of oral creatine and resistance training on serum myostatin and GASP-1. Molecular and Cellular Endocrinology 317 (1–2): 25–30.