Related Experiment Videos
Relationship between stress hormones and testosterone with prolonged endurance exercise
W Daly1, C A Seegers, D A Rubin
1Endocrine Section, Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA.
European Journal of Applied Physiology
|December 25, 2004
Summary
Endurance exercise impacts male hormones. Prolonged running showed cortisol negatively correlates with testosterone, supporting theories on lower testosterone in endurance athletes.
Area of Science:
- Exercise Physiology
- Endocrinology
- Sports Science
Background:
- Previous research suggests inverse relationships between testosterone and stress hormones like cortisol and prolactin in humans.
- These findings have been hypothesized to explain lower resting testosterone levels observed in some endurance-trained males.
- However, the specific hormonal responses during and after prolonged endurance exercise remain underexplored.
Purpose of the Study:
- To investigate the relationship between total and free testosterone, and cortisol and prolactin levels following prolonged endurance exercise in trained males.
- To examine how acute endurance exercise influences these key hormonal markers.
Main Methods:
- Twenty-two endurance-trained males completed prolonged treadmill running to volitional fatigue at 100% of their ventilatory threshold.
- Blood samples were collected at baseline, volitional fatigue, and at 30, 60, 90 minutes, and 24 hours into recovery.
- Measurements included total testosterone, free testosterone, cortisol, and prolactin.
Main Results:
- Prolonged exercise significantly altered total testosterone, cortisol, and prolactin levels from baseline.
- Cortisol and prolactin remained elevated post-exercise, while total and free testosterone showed significant reductions later in recovery (90 min and 24h).
- A significant negative correlation was found between peak cortisol response and subsequent total testosterone levels.
Conclusions:
- The study provides evidence supporting a link between stress hormone responses, particularly cortisol, and testosterone levels in endurance-trained males.
- Findings lend credence to the hypothesis that stress hormone interactions may contribute to the lower resting testosterone observed in endurance athletes.
- Free testosterone did not show significant acute changes during the immediate exercise and early recovery phases.