Women have made tremendous advances in the sporting arena. Progressive legislation for equality in organized sports and changing societal and cultural views have led to women participating in sports in unprecedented numbers. Women are not only competing in sports previously played by men only, such as ice hockey and rugby, but they also are encroaching on performance standards set by men. As of 1999, the difference between the men's and women's 100-meter world record times, 9.84 and 10.49 seconds, respectively, is a mere 6.6%. Women respond to physical training as do men: they have decreased blood pressure and heart rate, a reduced percentage of body fat, and increased maximal aerobic capacity. Physiologic differences between male and female athletes are minimized by correcting for lean body mass. The gender differences that do exist start to manifest after puberty, when the male and female sex steroids exert their influence on anatomic structures and metabolic processes.

Women must deal with fluctuating levels of hormones throughout their lives from puberty to menopause. During their reproductive years, they generally are exposed to a predictable pattern of endogenous hormones during regular ovulatory menstrual cycles, or they may be exposed to exogenous hormones by taking oral contraceptive (OC) pills that regulate their cycles for them. To what extent normal menstrual function and OC control of menstrual function affect athletic performance is less clear. This article discusses this complex and intriguing question, and also briefly reviews normal menstrual physiology and the actions of the sex steroids estrogen, and progesterone.