Changes in glutamine and glutamate concentrations for tracking training tolerance

Purpose: The purpose was to monitor high-performance athletes throughout tr aining macrocycles and competitions and examine the changes in plasma gluta mine (Gm) and glutamate (Ga) concentrations in order to develop a model of tolerance to training. Methods: Plasma glutamine and glutamate concentratio ns of 52 National team athletes; (31 male and 21 female) divided into male and female groups of speed skating, swimming, and cross-country skiing were measured in an early season rested condition to determine highest Gm and l owest Ga concentrations and over 2-4 macrocycles, which included heavy trai ning to establish lowest Gm and highest Ga concentrations. Results: In the rested condition, there were no differences within and between the male and female groups, excluding five athletes (OTA) who became overtrained in hea vy training. The mean (+/-SD) Gm concentration was 585 +/- 54 mu mol.L-1, G a concentration 101 +/- 16 mu mol.L-1, and Gm/Ga ratio 5.88 +/- 0.84 mu mol .L-1. The OTA had a significantly higher Ga concentration of 128 +/- 16 mu mol.L-1 and lower Gm/Ga ratio of 4.43 +/- 0.49 mu mol.L-1 than all the othe r groups. In heavy training, there was a significant decrease (P < 0.05) in Gm concentration to 522 +/- 53 (mu mol.L-1, significant increase in Ga con centration to 128 +/- 19 (mu mol.L-1 and significant decrease in Gm/Ga rati o to 4.15 +/- 0.51 mu mol.L-1. The OTA Crm concentration of 488 +/- 31 mu m ol.L-1 was significant lower than only the male speed skating and swimming groups. However, the Ga concentration of 171 +/- 17 mu mol.L-1 and Gm/Ga ra tio of 2.88 +/- 0.27 mu mol.L-1 were significantly higher and lower respect ively than all other groups. Conclusions: Based on the changes in Gm and Ga concentration under different training conditions, we propose an athlete t olerance to training model where glutamine concentration reflects tolerance to volume of work and glutamate concentration reflects tolerance to high i ntensity training. We suggest that the Gm/Ga ratio may globally represent o verall tolerance to training.