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Overtraining affects male reproductive status
A C Roberts1, R D McClure, R I Weiner
1Department of Human Biodynamics, University of California, Berkeley 94720.
Fertility and Sterility
|October 1, 1993
Summary
Intense exercise overtraining in men significantly lowers testosterone and sperm count while increasing cortisol. Hormonal levels and sperm concentration returned to normal after training reduction.
Area of Science:
- Endocrinology
- Sports Medicine
- Reproductive Health
Background:
- The hypothalamic-pituitary-gonadal axis regulates reproductive function.
- Strenuous exercise can impact hormonal balance.
- Understanding exercise's effect on male reproductive hormones is crucial for athletes.
Purpose of the Study:
- To investigate the impact of overtraining on the hypothalamic-pituitary-gonadal axis in endurance-trained men.
- To determine the relationship between testosterone, cortisol, and sperm concentration during overtraining.
Main Methods:
- A longitudinal study involving five endurance-trained male volunteers.
- Overtraining was induced by doubling weekly training volume.
- Hormonal (testosterone, cortisol) and sperm concentration were measured bimonthly before, during, and after the overtraining period.
Main Results:
- Overtraining led to a significant decrease in basal testosterone levels and a significant increase in basal cortisol levels.
- A strong negative correlation (r = -0.92) was observed between testosterone and cortisol.
- Sperm concentration decreased by 43% immediately after overtraining and 52% three months later, though remaining within normal fertility ranges.
Conclusions:
- Overtraining in men disrupts the hypothalamic-pituitary-gonadal axis, characterized by reduced testosterone and elevated cortisol.
- The observed hormonal changes may be linked to a subsequent decrease in sperm concentration.
- Hormonal and sperm parameters normalized after a period of reduced training intensity.