Monthly period prevents women from participating in various sports medicine research. This leads to their wide underrepresentation in exercise, sport and even drug studies, experts found.
An analysis of published exercise and sports studies discovered a gender gap wherein a woman's menstruation is highlighted as the major barrier.
According to University College London PhD student Georgie Bruinvels, women undergo changes in hormone levels monthly through the menstrual cycle, which makes women more complex.
Bruinvels also highlighted the lack of scientific studies on how menstrual cycle affects a woman's sports performance and training. While some studies did look into women who exercise, the information is often limited since female participants are often tested during the phase when their hormone levels are low.
Some studies include female participants who are on birth control pills, which also creates an imbalance in the findings, while some researchers put a blind eye on the possible impacts of the changes in hormone levels during menstruation.
"Women athletes have to compete at all phases of their menstrual cycles, yet currently only a snapshot of time is being researched," added Bruinvels.
In the past, women were not allowed to participate in the studies, especially drug trials, due to concerns that the drugs might be harmful to unborn babies. Other researchers pointed out to women being "more physiologically variable than men" as their reason to exclude female participants in the studies.
In an editorial, experts explained that men were typically deemed as "adequate proxies." This view considered the years of women's underrepresentation insignificant, but experts said otherwise.
Endocrinology professor Dr. Jerilynn Prior from the University of British Columbia said men are not "adequate replacements" for female participants in scientific research. She highlighted that millions of men and women take the same prescribed drugs every single day. Ironically, these drugs were tested on men alone. Therefore, this leads to an imbalance when women are exempted from drug trials.
"Half the human race doesn't have accurate information about the response to whatever the intervention is. It's like comparing apples and oranges," added Prior, who is also the scientific director and founder of the Centre for Menstrual Cycle and Ovulation Research in Canada.
This kind of disparity still exists today regardless of policies. For instance, the Canadian Institutes of Health Research obliges researchers to disclose how their study handles sex and gender differences whenever they apply for grants.
Bruinvels added that women's response to drugs is different than men's. Women's underrepresentation in drug trials can lead to dire consequences. The editorial was published in the British Journal of Sports Medicine on June 6.