Relationship between stress hormones and testosterone with prolonged endurance exercise

• Published in: European journal of applied physiology 2005-01, Vol.93 (4), p.375-380
• Main Authors: Daly, W, Seegers, C A, Rubin, D A, Dobridge, J D, Hackney, A C
• Format: Article
• Language: English
• Subjects: Adult; Androgens; Humans; Hydrocortisone - blood; Male; Physical Endurance - physiology; Physical Exertion - physiology; Physical Fitness - physiology; Prolactin - blood; Stress, Physiological - blood; Stress, Physiological - physiopathology; Testosterone; Testosterone - blood
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-004-1223-1

Previous pharmacological and pathological studies have reported negative relationships between circulating testosterone and certain stress hormones (i.e., cortisol and prolactin) in humans. These relationships have subsequently been used in hypotheses explaining the subclinical resting testosterone levels often found in some endurance-trained males, but as of yet no one has specifically examined these relationships as they relate to exercise. Thus, we examined the relationship between total and free testosterone levels and cortisol, and between total and free testosterone and prolactin following prolonged endurance exercise in trained males. Twenty-two endurance-trained males volunteered to run at 100% of their ventilatory threshold (VT) on a treadmill until volitional fatigue. Blood samples were taken at pre-exercise baseline (B0); volitional fatigue (F0); 30 min (F30), 60 min (F60), and 90 min (F90) into recovery; and at 24 h post-baseline (P24 h). At F0 [mean running time = 84.8 (3.8) min], exercise induced significant changes (P