Aspartate as an ergogenic supplement

Aspartate has been regularly listed in exercise physiology textbooks as an ergogenic substance since the first known trial by Professor Henri Laborit's laboratory in the late 1950s, aimed at verifying its ergogenic potential. The main outcomes of aspartate supplementation are attenuation of exercise-induced hyperammonaemia and increase of exercise endurance. In the available literature, the impact of aspartate on endurance seems generally favourable in humans, but it is not so favourable in experimental animals. In studies reporting increased endurance, no correlation has been found between its dosage and the increment of exercise time. Mechanisms supposed to explain the ergogenic effect of aspartate have also been reviewed in this article. Claims of a glycogen-sparing action, reduced hyperammonaemia and a higher rate of free fatty acid oxidation have not been confirmed unequivocally by the literature. Aspartate has not been shown to increase muscle endurance or strength. It is often used in combinations that are briefly reviewed in this article. However, the number of studies are presently too low to draw conclusions about the efficacy of these aspartate combinations. Furthermore, as in most studies on supplements, including aspartate alone or in combination, it is difficult to exclude a potential publication bias against non-significant results.