Creatine: it's a supplement discussed in hushed, foreboding tones around the gym lockers, and rarely mentioned outside of sporting circles, such is its social stigmatisation. It's the sporting world's 'entry drug', give in to the dark side embracing the 'Big C' and you're on the fast track to an obligatory doping scandal. Well the truth is that's a lot of old bunkum, instead it's time to recognise creatine for what it really is, the 'champagne of sports supplements' with benefits extending far past just being an extremely effective ergogenic aid.
If I was to ever open up a sports supplement shop, under performance enhancers I'd have simply two sections, one side a Starbucks for our caffeine fix, the other shelves and shelves of creatine, and that's it. Creatine is most aptly described by the ISSN stating that creatine monohydrate is the "most effective ergogenic nutritional supplement currently available to athletes in terms of increasing high-intensity exercise capacity" [1]. A review showed that by 2003, approximately 300 studies had examined creatine as a physical performance enhance, and 70% showed significant results with the majority of the remaining 30% showing a non-significant positive trend [2]. Short term supplementation improves "maximal power/strength (5-15% -improvement), work performed during sets of maximal effort muscle contractions (5-15% -improvement), single-effort sprint performance (1-5%-improvement), and work performed during repetitive sprint performance (5-15% -improvement)" [2]. The American College of Sports Medicine's round-table discussion concluded that the greatest improvements are found in high power output exercises repeated for a number of bouts [3].
As we see how creatine works we begin to understand its true value and the ludicrousness of its tainted rep. Creatine is a natural substance already found in the body. An omnivourous diet will typically supply about 1g of creatine a day, and synthesis of 1g from the kidney and liver also occurs [4]. Degradation of creatine in the body occurs at about 2g a day, thus matching intake and a steady state/balance is achieved [5]. But, by taking supplements we can increase these muscle stores even greater. Typically, a loading dose regime of 5g four times a day for five days will increase muscle creatine concentration by circa 20%, though a wide range of variation exists [6]. After this 2-3gram a day will maintain these increased concentrations.
Our skeletal creatine is used to produce a substance called phosphocreatine, an essential energy supply for activity, utlised especially in very high intensity exercise performed in repeated succession. This is not just limited to weight trainers or sprinters, but encompasses many sports such as soccer, rugby, gaelic, basketball etc where a stop go approach of exertion followed by relaxation is common. And, thus on a basic level the more creatine we have, the more phosphocreatine we make, the more energy we have and the longer it takes to hit fatigue.
But, this is just the beginning of a litany of benefits now attributable to creatine use.
Testimonies of improvement in endurance performance form supplementation are now also emerging. Muscle glycogen -a major fuel in endurance activity- increases proportionally to the extent of increase in muscle creatine levels. A five day loading phase increases glycogen levels on average by about 18% [7]. A useful approach is to supplement 5g 4x/day for periods of carbohydrate loading.
It is this increase in muscle glycogen formation and increased skeletal muscle glucose uptake which confers the possibility of creatine supplementation being a useful strategy in diabetes management. Indeed, the early findings of a small short-term intervention study in type 2 diabetics found the effects of creatine 5g/day with moderate exercise on reducing blood sugar levels (measured through HB1Ac) were similar to that experienced by the popular treatment drug metformin [8].
As already mentioned, our daily creatine needs are met 50:50 by the body and diet. It is meat products that supply this dietary side of our intake. Muscle samples from vegetarians show lower levels of creatine, and studies suggest that supplementation may dramatically improve memory and choice reaction time [9]. Low dose supplementation of even 1-2g/day may offer a useful supplement choice to even the non-active vegetarian.
So all in all there are many groups that could benefit from creatine supplementation. But, with the creatine prejudice that exists comes some disconcerting health concerns. So, to set it straight, one, creatine does not impair kidney function through a rise in the waste material creatnine, it's a misunderstanding of basic biochemistry. Two, creatine is selective for skeletal muscle and does not affect our heart muscles. Creatine appears to be an extremely the safe supplement with studies of up to five years failing to find any significant side effects to report.
1.Buford, T.W., et al., International Society of Sports Nutrition position stand: creatine supplementation and exercise. J Int Soc Sports Nutr, 2007. 4: p. 6.
2.Kreider, R.B., Effects of creatine supplementation on performance and training adaptations. Mol Cell Biochem, 2003. 244(1-2): p. 89-94.
3.Terjung, R.L., et al., American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc, 2000. 32(3): p. 706-17.
4.Persky, A.M. and G.A. Brazeau, Clinical pharmacology of the dietary supplement creatine monohydrate. Pharmacol Rev, 2001. 53(2): p. 161-76.
5.Walker, J.B., Creatine: biosynthesis, regulation, and function. Adv Enzymol Relat Areas Mol Biol, 1979. 50: p. 177-242.
6.Greenhaff, P., The nutritional biochemistry of creatine. The Journal of Nutritional Biochemistry, 1997. 8(11): p. 610-618.
7.van Loon, L.J., et al., Creatine supplementation increases glycogen storage but not GLUT-4 expression in human skeletal muscle. Clin Sci (Lond), 2004. 106(1): p. 99-106.
8.Rocic, B., et al., Comparison of antihyperglycemic effects of creatine and metformin in type II diabetic patients. Clin Invest Med, 2009. 32(6): p. E322.
9.Benton, D. and R. Donohoe, The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores. Br J Nutr, 2011. 105(7): p. 1100-5.