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Does a Woman’s Period Affect Her Athletic Performance?

Exercise scientists don’t really know, and that’s a problem, according to a new editorial.

By Kate Wheeling


(Photo: John Gichigi/Getty Images)

Women’s athletics has long been held back by shaky science. Take boxing, for example: Last year, Amelia Schonbek wrote for Pacific Standard about the battles that female boxers must face against sexism and physiological misconceptions before they ever get in the ring:

For almost as long as women have wanted to box, they have been met with the argument that fighting would be uniquely harmful to them. Many such concerns initially centered on women’s reproductive health. In the 1930s, the boxing commentator Nat Fleischer argued that female fighters would have problems bearing (or breastfeeding) children. In the ’70s, the Amateur Athletic Union barred women from competing in boxing tournaments because, according to the organization, taking hits to the chest would lead to the development of breast cancer. Some groups, like the Pennsylvania State Athletic Commission, allowed women boxers to fight, but only if they wore aluminum bras to protect against this cancer risk. Around the same time, the California State Athletic Commission gave its first boxing licenses to female fighters. But certification came with one degrading condition: A woman could only compete if she’d certified, before her bout, that she did not have her period.

A perceived lack of endurance has limited women’s fight times, and, because of this shortened fight time, female fighters are paid less than their male counterparts. But countering such pseudoscience has proven difficult, because women are still largely under-represented in sport and exercise studies.

Historically, researchers were reluctant to include women as research subjects. The menstrual cycle is a confounding variable, and instead of designing experiments to account for the potential effects of the menstrual cycle on study outcomes, researchers opted to study only men. But according to a new editorial in the British Journal of Sports Medicine, increased research on the effects of female physiology and hormone cycles on athletic performance is necessary to understand the documented differences between men’ and women’s bodies’ response to exercise.

The problem is that men have proven to be inadequate stand-ins for women in medical research. “Evidence suggests that women are almost twice more likely to have an adverse reaction to a drug than their male counterparts, and 80% of drugs withdrawn from the market are due to unacceptable side effects in women,” the authors of the editorial write.

Any research on exercise and athletic performance that ignores the effects of hormones in women — which can affect their blood pressure and metabolism — will never fully capture female athletic performance. More than 40 percent of women believe their periods have a negative effect on their athletic performance, according to the authors, but research on the subject is still too limited to provide meaningful explanations or solutions to athletes.

Both the real and imagined effects of ovarian hormones on athletic performance discourage female participation; women still make up less than half of high school and college athletes. Resolving some of these remaining questions could help to counter the persistent gender disparity in sports, and give women equal opportunities in the ring.