2. Hypothalamus-Pituitary-Gonadal Axis in ATHLETICS Dr.Sh.Hezarkhani

3. Male Gonadal Axis

4. Hypothalamus-Pituitary-Gonadal Axis The effects of physical activity on the male reproductive axis vary with the : 1) intensity and duration of the activity 2) fitness of the individual 3) his nutritional-metabolic status.

5. Male Gonadal Axis Relatively short, intense exercise usually increases testosterone levels while more prolonged exercise usually decreases serum testosterone levels

6. Male Gonadal Axis Endurance and other forms of training can induce subclinical inhibition of normal reproductive function although clinical expression of reproductive dysfunction with exercise is uncommon in men

7. Male Gonadal Axis Increased serum testosterone levels have been reported during: - relatively strenuous free and treadmill running - weight training - ergometer cycling The testosterone response has been reported to increase with increased exercise load

8. Male Gonadal Axis Acute exercise-induced testosterone increments are also seen in older men the exercise-associated increment in circulating testosterone is not mediated by LH specific testicular mechanisms are involved

9. Male Gonadal Axis more prolonged exercise suppression of serum testosterone

10. Male Gonadal Axis The decrease of testosterone synthesis, is due to : 1) gonadotropins 2) cortisol or catecholamine levels 3)accumulation of metabolic waste materials

11. Male Gonadal Axis The fall in serum testosterone must result from: 1- decreased production rates 2-decreased binding 3- increased clearance

12. Male Gonadal Axis Endurance and other forms of training can induce subclinical inhibition of normal reproductive function. Libido may also be reduced in some athletes during intense endurance training periods, due to reduced testosterone levels and to chronic fatigue.

13. Male Gonadal Axis Semen analysis ↑ β-endorphin ↓ or ↑ PRL ↑ cortisol

14. Female Gonadal Axis

15. can be affected by 1- physical and 2- psychological factors

16. Female Gonadal Axis Many female athletes develop : - Delayed menarch - oligomenorrhea - amenorrhea - and luteal phase defects

17. Female Gonadal Axis -Negative energy balance -leptin -which serves as a signal to the CNS with information on the critical amount of adipose tissue stores that is necessary for GnRH secretion and pubertal activation of the hypothalamic-pituitary-gonadal axis

18. Female Gonadal Axis Possible alternative mechanisms : - stress-induced activation of the H-P-A axis - endogenous opioid peptides - catecholestrogens - hyperandrogenism.

19. Prolactin -transiently increase with exercise -proportional to the exercise intensity -PRL increments occur when the anaerobic threshold is reached

20. Prolactin Prolactin correlated with levels of: - POMC derivatives - ACTH - β-endorphins -changes in body temperature - dehydration -is exaggerated by stress - is reduced with habituation and hypoxia