Int J Sports Med 1992; 13(3): 230-235
DOI: 10.1055/s-2007-1021259
© Georg Thieme Verlag Stuttgart · New York

Stability and Variability in Hormonal Responses to Prolonged Exercise

A. Viru, K. Karelson, T. Smirnova
  • Department of Exercise Biology, Tartu University, 18 Ylikooli, Tartu EE2400 Estonia
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Publication History

Publication Date:
14 March 2008 (online)

Abstract

To study the dynamics of alterations in blood hormones and their individual variability during prolonged exercise, changes in plasma levels of corticotropin, cortisol, aldosterone, testosterone, progesterone, somatotropin, insulin and C-peptide were recorded in 32 endurance athletes and 50 untrained persons during a 2-hour exercise on a cycle ergometer at 60% V̇O2max. Common changes were activation of the pituitary corticotropin function, mostly at the end of exercise, rises in aldosterone and somatotropin concentrations and decreases in insulin and C-peptide levels during exercise. The activation of pituitary-adrenocortical System and the decrease of insulin but not C-peptide levels were more pronounced in athletes than in untrained persons. A large inter-individual variability existed in changes of cortisol, testosterone and progesterone in both groups. Five variants were found in the dynamics of cortisol concentration. Whereas the alterations of corticotropin were characterized mainly by a biphasic increase, the dynamics of corticotropin and cortisol coincided only in one variant out of five. Most characteristic for the post-exercise recovery period were decreased activity of the pituitary-adrenocortical system and delayed normalization of aldosterone level.