The present study examined the relationship between rate of abnormal menstrual cycles in women who participated in competitive sports and long-term fertility. Longitudinal menstrual data were collected over 25 years from 33 women who graduated from physical education collegesThe results were as follows:1)Among the 33 women surveyed, the number of pregnancies for each woman ranged from zero to eight; the total number of pregnancies was 85 (mean 2.6). Sixty-five (76.5%) of the 85 pregnancies were carried out to delivery times.2)The rate of spontaneous abortion was 15.3%. Four (12.1%) of the 33 women were infertile.3)In women with fertility-related problems such as infertility, spontaneous abortion, premature delivery, and stillbirth, the rate of abnormal menstrual cycles tended to be higher with increase of the fertility-related problems.4)In women with a high rate of abnormal menstrual cycles during college, the rate continued to be high after graduation.5)In women without fertility-related problems, the rate of abnormal menstrual cycles during college varied widely. Also, the rate of abnormal menstruation decreased less than 30% after graduation, excluding one woman. Conversely, in women with fertility-related problems, the rate of abnormal menstrual cycles was higher than in women without fertility problems both during college and after graduation.6)Changes in menstrual cycle length with age were more different than an individual. In women with fertility-related problems, abnormal menstrual cycles were observed between the ages of 18 and 42, and abnormal cycles were both longer and shorter than normal cycles.The results indicated that, in women who participated in competitive sports during their youth, abnormal menstrual cycles may remain long after retirement from sports. In addition, problems such as infertility and spontaneous abortion were observed to be associated with higher rates of abnormal menstrual cycles.