Fatigue pp 315-320

Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 384)

Tryptophan, 5-Hydroxytryptamine and a Possible Explanation for Central Fatigue

  • E. A. Newsholme
  • E. Blomstrand

Abstract

In prolonged exercise the plasma level of branched-chain amino acids (BCAA) may fall and that of fatty acid increases: the latter increases the free tryptophan level, so that the plasma concentration ratio, free tryptophan/BCAA may increase leading to higher levels of tryptophan and therefore of 5-hydroxytryptamine (5-HT) in brain. The latter increases the activity of some 5-HT neurons in the brain which can cause sleep and which could, therefore, increase the mental effort necessary to maintain athletic activity. Drinks containing branched-chain amino acids should restore vigor to athletes whose performance is depressed by an excess of cerebral 5-HT. Recent work suggests that intake of branched-chain amino acids may improve performance in slower runners in the marathon and decrease perceived physical and mental exertion in laboratory experiments. This suggestion is supported by pharmacological manipulations that result in either increased or decreased physical performance.

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Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • E. A. Newsholme
    • 1
  • E. Blomstrand
    • 2
  1. 1.Cellular Nutrition Research Group, Department of BiochemistryUniversity of OxfordOxfordUK
  2. 2.Pripps Research LaboratoryPripps BryggeriBrommaSweden

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