Effects of a competitive triathlon on plasma concentrations of tryptophan and branched-chain amino acids

Abstract

The aim of this work was to determine the acute responses of tryptophan and branched chain amino acids to a triathlon competition. Fourteen male triathletes were studied. All took part in a international triathlon race consisting of 1,5 km swimming, 40 km biking and 10 km running. Venous blood samples were drawn before (-24 h) and after (15 min) the triathlon. Plasma concentration of branched chain amino acids and total and free tryptophan were determined. Branched chain amino acids decreased from 463 -108.3 to 364 -98.9 m ol/L (p < 0.03). Free tryptophan increases from 9.2 to 16.3 m ol/L (p < 0.006). Furthermore the ratio of free trytophan to branched chain amino acids increased from 2.07 -0.48 to 4.24 -0.79 (p < 0.001). This increases the rate of transport of tryptophan accross the blood-brain barrier and also increases the rate of synthesis of 5-hydroxytryptamine in the central nervous system. A high presence of 5-hydroxytryptamine in the brain develops physical and mental fatigue during the triathlon. This data support the participation of amino acids in fatigue process during triathlon. UNITERMS: Fatigue; Triathlon; Tryptophan.The triathlon has become one of the most popular endurance events (Osorio et alii, 1990;Osorio & Donoso, 1990). Diversity of training is indoubtedly a major reason, but the distances of competition also account for the popularity of this sport.In the ofder to be a succesfull triathlete in this sport, fatigue should be delayed in extreme. Certain amino acids can participate in this process. In fact, although amino acids are the precursors for protein synthesis, they also act as precursors for certain neurotransmitters. For example, tryptophan is converted in the brain to a neurotransmitter known as 5-hydroxytryptamine, which play a role in influencing mood.The ratio in the bloodstream of the levels of tryptophan to branched chain amino acids could control the rate of entry of tryptophan into the brain. This fact affects the concentrations of 5hydroxytryptamine and hence behaviour. A reduction in the concentration of branched amino acids in the

Supplementing Branched Chain Amino Acids on Some Hormone Responses of Athletes

“…Morales found through research that branched chain amino acids can increase the rate of protein synthesis and metabolism in athletes, thereby increasing the athlete's physiological response and keeping the mental state in a good state [7]. In order to study the effect of supplementing branched chain amino acids on certain hormone responses of athletes, Osorio used modern instruments and immune tracking methods to conduct research from the molecular level, and found that branched chain amino acids can increase growth hormone in athletes, which can be greatly improved, alleviate sports fatigue of athletes [8].…”