A comparative study of the effect of acute exercise on the hypothalamic-pituitary-gonadal axis between trained and non-trained human male subjects.

Abstract

The purpose of this study was to compare the effects of acute exercise on plasma testosterone, LH, FSH and prolactin. In addition, the effects of LH, FSH, Prolactin and physical fitness on testosterone levels were investigated. The serum levels of testosterone, LH, FSH and prolactin were measured at rest, immediately after, 30 minutes and 60 minutes after acute exercise, which comprised of running on a treadmill at 70% of the subjects' previously determined MVO$\sb2$ for 20 minutes. Trained (n = 12) and untrained (n = 9) male subjects were tested. Mean testosterone levels increased significantly (p 0.01) in both groups immediately after cessation of exercise, independent of the effects of LH, FSH and prolactin. Testosterone responses to exercise were significantly (p 0.01) greater in trained (45% increase) than in the untrained (19.5% increase) group. In addition, basal levels of testosterone were significantly lower (p 0.01) in the trained group compared to the untrained group.