1. An increased uptake of tryptophan in the brain may increase serotoninergic activity and
recently has been suggested to be a cause of fatigue during prolonged exercise. The …

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 …

Previous studies have shown that sustained exercise in human subjects causes an increase
in the plasma concentration ratio of free tryptophan: other large neutral amino acids …

The plasma concentrations of branched‐chain and aromatic amino acids have been
measured in two different types of sustained dynamic exercise. Twenty‐two subjects …

There is an increasing interest in the mechanisms behind central fatigue, particularly in
relation to changes in brain monoamine metabolism and the influence of specific amino …

Summary Brain serotonin (5-hydroxytryptamine, 5-HT) has been suggested to be involved in
central fatigue during prolonged exercise. Changes in the ratio of plasma free tryptophan …

Aim: This study investigated the effect of prolonged exercise with and without carbohydrate
intake on the brain exchange of amino acids, especially focussing on tryptophan and …

On two occasions, seven male endurance‐trained cyclists performed exhaustive exercise on
a cycle ergometer in the morning after they had performed a bout of exercise the preceding …

In both trained and untrained rats, exercise increased the plasma concentration ratio of
aromatic amino acids to branched-chain amino acids which might favour entry of the …

It has been suggested that an elevated concentration of the neurotransmitter serotonin (5-
hydroxytryptamine, 5-HT) in specific areas of the brain may contribute to the development of …