Int J Sports Med 1995; 16(3): 155-159
DOI: 10.1055/s-2007-972984
Physiology and Biochemistry

© Georg Thieme Verlag Stuttgart · New York

Serum Amino Acid Concentrations in Nine Athletes Before and After the 1993 Colmar Ultra Triathlon

M. Lehmann1 , 3 , M. Huonker1 , F. Dimeo1 , N. Heinz1 , U. Gastmann1 , N. Treis1 , J. M. Steinacker3 , J. Keul1 , R. Kajewski2 , D. Häussinger2
  • 1Department of Sports and Performance Medicine, University Medical Hospital, Freiburg, Germany
  • 2Department of Gastroenterology, University Medical Hospital, Freiburg, Germany
  • 3Department of Sports and Performance Medicine, University Medical Hospital Ulm, Germany
Further Information

Publication History

Publication Date:
09 March 2007 (online)

The amino acid imbalance hypothesis should explain the fatigue originating in the brain during sustained exercise or overtraining as a branched-chain (BCAA)/aromatic amino acids (AAA) imbalance with increased brain tryptophan uptake and 5-hy-droxytryptamine synthesis. The serum amino acid profile was determined in 9 ultra-triathletes before and after completing the 1993 Colmar ultra-triathlon to additionally analyse the extent of this amino acid imbalance during such an extreme prolonged contest lasting more than 23 hours. The summed serum concentration of 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 decrease in 18 individual amino acids by 9-56 %, an increase in cystine (± 38 %), methionine (± 24 %), tyrosine (± 10 %), phenylalanine (± 12 %), free tryptophan (± 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 decrease 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.

    >