Increased serotonin levels in physically trained men.

It has been postulated that exercise training influences monoaminergic systems. The purpose of the present study was to determine the basal level of serum serotonin (5HT) in track and field-trained men (N = 15) and in untrained subjects matched by age, weight and height (N = 15). Serum serotonin levels were determined in blood drawn into dry tubes after a 12-h fast by high performance liquid chromatography utilizing electrochemical detection. Mean (+/- SD) serum serotonin levels were: 141.32 +/- 38.77 ng/ml for trained subjects and 97.77 +/- 30.53 ng/ml for untrained subjects (P < 0.01, Student t-test). These data show that basal serum serotonin levels are increased by exercise training.