Effect of pre-exercise single dose arginine ingestion on plasma amino acid profile during exhaustive exercise in elite male wrestlers

Abstract

Aim: The aim of this study was to investigate the possible effects of pre-exercise single dose arginine ingestion on plasma amino acid profile during incremental exercise to exhaustion. Methods: Ten volunteer elite male wrestlers (age: 24.7±3.8) participated in this study. Testretest protocol was done on the same subjects. Exercise protocol started at 90 watts on bicycle ergometry and the load was increased 30 watts in every 3 min till the exhaustion. Arginine (1.5gr/10 kg body weight) or placebo were given to the subjects after 12 h fasting (during the night) and venous blood samples were collected 1 h after the supplementation (right before exercise protocol) and right after the exercise protocol for both test and retest. Plasma amino acid profiles were determined by HPLC. Results: Preand post-exercise arginine, ornithine and citrulline concentrations were significantly higher in arginine vs. placebo trial (p<0.05). Glutamine, tyrosine, methionine, phenylalanine, isoleucine and leucine concentrations increased following exercise only in arginine trial (p<0.05). Citrulline and tryptophan levels decreased while alanine levels increased after exercise in both trials (p<0.05). There was an increase following exhaustive exercise in total branched chain amino acid concentrations in arginine trial (p<0.05) whereas there is no significant change in placebo trial. Total amino acid concentrations were increased with exercise in both trials but post-exercise concentrations was higher in arginine trial compared to placebo trial (p<0.05). Conclusion: Results suggest that pre-exercise arginine supplementation can promote an amino acid profile that could be favorable for performance; however, further investigation is necessary to determine the effect of arginine supplementation on athletic performance.