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Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "
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04.03.2009 |
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More stamina with 3 g L-arginine-L-aspartate per day
According to field studies done in the seventies, L-arginine-L-aspartate [structural formula shown below] is a surprisingly effective performance-enhancing substance. But how the supplement works was not investigated at the time.
L-arginine lowers the concentration of lactic acid in the blood during physical exercise. It raises the aerobic capacity of the body, probably by increasing the blood supply to the body's cells. L-arginine is a precursor of NO, which widens blood vessels [vasodilation for the technically minded].
It is believed that NO stimulates the cells uptake of glucose and inhibits the conversion of proteins into glycogen.
L-aspartate increases fat burning and reduces glycogen burning in muscle tissue, in theory. L-aspartate is a direct precursor of oxaloacetate. Oxaloacetate is released during the citric acid cycle, a complex universal reaction in which energy is generated from fats, carbohydrates and proteins.
The researchers set up an experiment to find out if this is actually what happens. They gave sixteen students a daily dose of 3 g of L-arginine-L-aspartate for three weeks and got them to cycle on an ergometer. The students had to cycle for three minutes at a speed that generated 150 watts – no more and no less. This meant the researchers could test the effect of L-arginine-L-aspartate on short sub-maximal exercise.
An equal-sized group of students were given a placebo for the three weeks.
At first the supplement lowered lactate levels. See the figure above. The top of the two figures shows the results of the experimental group; the lower of the two shows the results of the placebo group. Pre-test = before the test, re-test = after.
The table below shows the other effects of L-arginine-L-aspartate on the test subjects' bodies.
Fat burning increases slightly, carbohydrate burning decreases slightly.
L-arginine is the most frequently used NO-booster, but it is perhaps not the most effective. L-citrulline has a better track record. An alternative for L-aspartate is L-malate.
L-citrulline-L-malate used to be marketed as Stimol. It was popular with cyclists in the seventies and reappeared on the market as a supplement.
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