Menstrual cycle, contraception, and performance.

Although understanding of the unique physiology of the female athlete has increased, there are still many questions to be answered. Endogenous and exogenous female sex steroids have been shown to influence various cardiovascular, respiratory, and metabolic parameters, but these changes probably have minimal impact on the ability of most recreational athletes to participate in and enjoy their sport. Statistically significant data may or may not have clinical or performance relevance. By the same token, a statistically nonsignificant change may mean the difference between first and second place to an elite athlete. For an athlete concerned about maximizing performance, individual variability in menstrual cycle changes to various performance parameters must be considered. It is difficult to predict how accurately controlled laboratory findings from a study population apply to an individual competitor on the playing field. Athletes taking OCs for contraception or for menstrual cycle control may be able to minimize any potential side effects and performance influences by taking the lower dose triphasic pills and the newer progestins. For women with menstrual dysfunction, OCs may provide a predictable hormonal milieu for training and competition. Further scientific study is needed using large-scale, prospective, randomized clinical trials on trained athletes and accurate hormonal measurements to determine the phase of the menstrual cycle to determine short- and long-term effects of cycle phase and OCs in exercising women. As more questions continue to be answered, physicians and sport scientists will be better able to guide women not only to maximize their performance but to ensure lifelong good health.