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Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

11.05.2009

PEGylated creatine is disappointing

The stuff that supplement seller GNC is trying to use to supersede competing products containing old-fashioned reliable creatine goes by the official name of GNC Pro Performance Amplified Creatine. According to a study done at the University of Oklahoma, Amplified Creatine is a lot of hot air. But you only discover this if you read the whole study. The abstract – which is what the sales reps will be bombarding you with soon on the message boards – tells a different story.

The active ingredient in Amplified Creatine is, to use supplement industry jargon, Polyethylene Glycosylated Creatine. This is creatine that has been mixed with the PEG sugar chain, so that it the body can absorb it more easily. That's why you need less of it, says manufacturer GNC. But to make a claim like this you need to do research. So GNC asked the researchers to produce a study showing that a small amount of Amplified Creatine works just as well as a full dose of creatine.

In the study, which will soon be published in the Journal of Strength and Conditioning Research, the researchers gave a dozen amateur athletes a placebo for a month. A dozen other athletes took 5 grams a day of creatine, a dozen took 1.25 grams of Polyethylene Glycosylated Creatine and another dozen took 2.5 grams daily of the new super-creatine.

The figure below shows how many kilograms the test subjects could lift for just one rep of a bench press at the end of the test period. (1RM) The graph shows the increase in the 1RM only.

CM = ordinary creatine. The old-fashioned stuff worked a tiny bit better, although the difference was not significant. But when the researchers looked at how many reps the test subjects managed to do at eighty percent of their 1RM, they also saw the same.

Then the researchers looked at the weight the test subjects could shift for just one leg press rep. This time the low dose of Amplified Creatine worked a bit better than the creatine, and the high dose less. Strange. But statistically both creatine and Amplified Creatine had the same effect.

The graph below shows what happened to the number of reps that the test subjects managed at eighty percent of the 1RM. The creatine group performed a little better, but again, statistically it made no difference what the test subjects took.

The creatine users put on weight and the test subjects in the other groups did not.

The researchers don't risk a general conclusion. Because in all tests five grams of cheap creatine works statistically just as well as smaller doses of the expensive Amplified Creatine, they conclude in their abstract that "PEG creatine may have ergogenic effects that are comparable to those of CM, but with a smaller dose of creatine".

The research results are exactly what you'd want to hear as a sponsor. But if you read the entire article, you can't avoid reaching a different conclusion.

Source:
J Strength Cond Res. 2009 May;23(3):818-26.

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