Gonadal steroids in athletic women contraception, complications and performance.

Gonadal steroids are altered by the reproductive system's adaptation to conditioning exercise. Contraceptive options for the athletic woman include all measures appropriate for the sedentary woman. Barrier methods (always with spermicidal jelly) are the preferred choice. The cardiovascular risks, decreased aerobic performance, and shorter time to muscular exhaustion related to oral contraceptives make this a less desirable option. Potential complications from the steroid changes of intense exercise include: low oestrogen and progesterone with risk of loss of trabecular bone and early osteoporosis, and absent progesterone with low normal oestrogen levels associated with risk of endometrial or breast cancer. Therapeutic options for the amenorrhoeic or young athlete include supplemental oral calcium, cyclic oral progesterone, or possibly cyclic physiological oestrogen and progesterone. The anovulatory (usually older) athlete with regular menses needs cyclic progesterone. Medroxyprogesterone 10mg on days 16 to 25 of the cycle or for 10 days monthly can potentially prevent endometrial and breast cancer, give predictable cycles, improve trabecular bone balance and stimulate the return of ovulatory cycles. A practical approach to anovulatory infertility in the athlete includes a 10% reduction in exercise intensity and/or an increase in percentage body fat to 18 to 20%. Cyclic vaginal progesterone (25mg bid) can then treat short luteal phase cycles. With improved understanding of the hormonal adaptations to conditioning exercise, we will be better able to outline contraceptive and therapeutic options in the future.