Cyclic ovarian function in recreational athletes

Abstract

In 17 female recreational athletes, ovarian function was monitored using daily hormone measurements and serial ultrasound determinations. Whereas 11 out of 13 women of a control group showed estradiol (E2) maxima beyond 470 pmol/l, progesterone (P4) maxima of 19 nmol/l or more, and a luteal phase length of 9 days or more, only 10 out of 17 athletes satisfied these criteria. Six athletes showed disturbed follicular development, and one athlete showed luteal phase disturbance. Both athletes with disturbed menstrual function (n = 7) and athletes fulfilling the above-mentioned minimal criteria (n = 10) had lower E2 concentrations in all phases of the menstrual cycle (P less than 0.05). P4 concentrations were significantly decreased in the group with disturbed menstrual function (P less than 0.05). Maximal aerobic capacity in the two athlete groups was similar. Neither athlete group showed the expected increase in caloric intake compared with the sedentary controls. It is concluded that recreational running is associated with altered ovarian function. Inadequate nutritional adaptation may be a contributing factor.

Lifetime recreational exercise activity and risk of breast carcinoma in situ

“…27,28 These alterations in menstrual function have been associated with reduced levels of estradiol, progesterone, and follicle-stimulating hormone, particularly during adolescence. 27,29,30 Studies of recreational athletes suggest that ovarian function may be altered in women who engage in less strenuous activity through lower mean hormone levels, longer menstrual cycle lengths, 31,32 or the occurrence of anovulatory menstrual cycles, 33 but to our knowledge the data are not as conclusive as those for athletes. Recent physical activity may also act through hormonal mechanisms by continuing to impact ovarian hormone levels among premenopausal women, may directly lower estrogen levels, 34 or may alter circulating estrogen levels of postmenopausal women indirectly 9 by lowering BMI or maintaining weight among postmenopausal women.…”

Self-experienced physical workload and risk of breast cancer

“…High levels of estrogens and progesterone play a central role in exposing breast tissue to harmful effects. Their serum levels are known to decrease with exercise (23), even with exercise of moderate intensity (24)(25)(26), under experimental conditions. Whether this mechanism holds true for occupational physical activity is not known, although moderate levels of physical activity, as found among cleaners, kitchen staff, and clerical workers at hospitals, appear to affect the female reproductive system, as measured by the time to pregnancy (ie, fecundability) (27).…”

Obesity, Hormone Receptor Status, and Breast Cancer Occurrence and Survival in New Mexico Hispanic and Non-Hispanic White Women

“…Potential etiologic mechanisms include changes in fat distribution, alterations in repro- ductive function and sex hormone levels, metabolic and growth hormones, and modulation of immune function (15,17,18). In addition, the protective effects of physical activity may be mediated directly through effects on ovarian and peptide hormone production in premenopausal women (29)(30)(31). A leading candidate mechanism is that high levels of physical activity result in a preferential reduction of intraabdominal fat stores that leads to lower exposure to estrogens and other hormonal breast epithelial cell mitogens, such as insulin-like growth factor 1 and insulin (15,17,18).…”