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

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Handful of ornithine caps before strength training boosts growth hormone level

Give a guy who weighs 80 kg a dose of 8 g L-ornithine HCl before a weight training session, and his growth hormone level will increase by a factor of three. Japanese researchers working for ornithine manufacturer Kyowa Hakko Bio have studied the effects of this amino acid on athletes.

It's not the first time we've written about publications by these researchers. According to their research, endurance athletes can improve their final sprint by taking ornithine, and ornithine also removes ammonia from the bloodstream during physical exertion.

The idea that ornithine supplements can boost the production of growth hormone after heavy training is not new, but it is controversial. Finnish researchers who gave weight lifters 2 g L-ornithine and 2 g L-arginine each day for a couple of days recorded no effect whatsoever on growth hormone levels. [Int J Sport Nutr. 1993 Sep; 3(3): 290-7.]

Researchers from Syracuse University gave bodybuilders 7 g L-arginine and observed that the post-training growth hormone production actually declined slightly. Polish researchers gave power lifters 10 g of an L-arginine and L-ornithine mixture daily and recorded a rise in growth hormone production. We call this conflicting evidence.

The Japanese gave ten young men, average age 22, 100 mg L-ornithine per kg bodyweight and then got them to do 8 sets of biceps exercises. The protocol is shown below. And for once the typos are not ours.

Handful of ornithine caps before strength training boosts growth hormone level

Handful of ornithine caps before strength training boosts growth hormone level

On another occasion the men trained after being given a placebo. A workout without ornithine led to a GH-level rise of factor 2 half an hour after the training session ended; a workout with ornithine led to a GH-level rise of factor 6.

The men were not used to strength training. The researchers suspect that experienced strength athletes would react less well to the supplementation. They base this on a study done by American researchers in 1990 [Int J Sport Nutr. 1992 Sep; 2(3): 287-91.] in which bodybuilders were given 40, 100 or 170 mg L-ornithine per kg bodyweight. Only the highest dose led to a rise in the growth hormone level.

Handful of ornithine caps before strength training boosts growth hormone level

If you want to boost growth-hormone levels with arginine or ornithine, then you apparently need hefty doses. The effective dose is even higher for experienced strength athletes, the Japanese suspect. Strength athletes' hormone balance is already so stimulated by their training, that only a very strong stimulus will boost growth hormone levels further. If this reasoning holds, a bodybuilder weighing 80 kg would therefore need not 8 g ornithine but almost 14 grams.

Some experienced strength athletes are sceptical about growth hormone-boosters. They don't deny that supplements can boost growth hormone levels, but they don't believe that the boost has any effect. They point to the doses that the users of pharmacological growth hormone preparations need to make any progression. These are of a different order than the small amount of extra growth hormone in the bodies of supplements users.

Advances in Bioscience and Biotechnology, 2010, 1, 7-11.

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