Athletic women often exhibit menstrual disorders such as luteal insufficiency, oligomenorrhea and amenorrhea are often seen. It has been suggested that such disorders are related to prolactin release caused by physical activity. To investigate the mechanism by which the disorders are promoted, prolactin secretion was studied in 10 athletic women (5 with normal ovulatory periods, and 5 with short luteal periods) and 6 non-athletic controls. Blood samples were obtained during the early follicular phase of the menstrual cycle through an indwelling venous catheter at 15-minute intervals for 4 hours. The concentration of prolactin was measured by radioimmunoassay.
The mean prolactin concentration in the athletic group was lower than that in the control group (p<0.001), and pulse frequency in the athletic group was higher than that of the control group (p<0.01) . Pulse amplitude in the athletic women with short luteal periods was higher than that of those with normal ovulation. Pulse duration in the athletic women with short luteal periods was significantly longer than that of those with normal ovulation (p<0.01) .
These findings suggest that prolactin is one of the most important factors in menstrual disorders in athletic women.
