L-Ornithine HCL as an Ammonia-Buffer for Hard Training Athletes

Figure 1: Chemical structure of
L-ornithine (HMDB v2.5)

Habitual readers of the SuppVersity will be familiar with the ergogenic effects of l-ornithine. A recent study by Demura et al. (Demura. 2010) verified the immediate effect of l-ornithine supplementation on ammonia and glutamate metabolism. In their 14 healthy young volunteers, who trained regularly, the scientists observed significant increases in plasma ammonia and glutamate upon supplementation of 0.1.g/kg body weight before the subjects conducted incremental exhaustive ergometer bicycle exercises. Interpreting their results as follows,

although the ingestion of L-ornithine hydrochloride before the exercise cannot be expected to improve performance, it does increase the ability to buffer ammonia, both during and after exercise,

Demura et al. are yet reluctant to postulate a direct effect on exercise performance.Such an effect has however already been reported in the 2008 study by Sugino et al., I already referred to in the introductory sentence of this item.