SERUM AMINO-ACID-CONCENTRATIONS IN 9 ATHLETES BEFORE AND AFTER THE 1993 COLMAR ULTRA TRIATHLON

The amino acid imbalance hypothesis should explain the fatigue origina ting in the brain during sustained exercise or overtraining as a branc hed-chain (BCAA)/aromatic amino acids (AAA) imbalance with increased b rain tryptophan uptake and 5-hydroxytryptamine synthesis. The serum am ino acid profile was determined in 9 ultra-triathletes before and afte r completing the 1993 Colmar ultra-triathlon to additionally analyse t he extent of this amino acid imbalance during such an extreme prolonge d contest lasting more than 23 hours. The summed serum concentration o f 25 amino acids decreased by 18% from 3962+/-846 to 3255+/-694 umol . l(-1) likely reflecting a catabolic state of the organism with a decr ease in 18 individual amino acids by 9-56%, an increase in cystine (+3 8%), methionine (+24%), tyrosine (+10%), phenylalanine (+12%), free tr yptophan (+74%), and constant glutamine, leucine and total tryptophan levels. Since plasma Volume increased by approximately 7.6% with a 3.3 kg body mass decrease in the athletes during the ultra triathlon, a d ecrease in intra-cellular water with an extra-cellular fluid increase is hypothesized. This decrease in cellular hydration state is seen as a protein-catabolic signal.