While women’s health is gaining wider attention, particularly around menopause and hormonal shifts, there are still major gaps in our understanding of female physiology. A Danish professor argues that long-standing gender biases in medical research have left women underserved and under-researched.
Hormones Make Research on Women More Complex
For nearly two decades, Mette Hansen, newly appointed professor of sports science at Aarhus University, has studied women’s hormones and how they affect physical performance, health, and muscle function. Despite recent progress, vast areas of knowledge remain unexplored, and Hansen believes this is partly due to an outdated but persistent assumption in science: that women are more complicated to study than men because of hormonal fluctuations.
In clinical research, consistency is key. When examining the effects of a single factor – such as caffeine – it’s essential to minimize other variables. Menstrual cycles introduce changes in hormone levels, which can cause fluctuations in study outcomes. Because of this, women have often been excluded from research to preserve data consistency.
For example, if researchers want to test women in the same phase of their menstrual cycle over three sessions, it takes at least three months to complete the tests. In contrast, data collection for men can be finished in less than a week. This perceived inconvenience has contributed to a gender gap in scientific research.
The Paradox of Exclusion
Ironically, excluding women due to hormonal variability has created a paradox. In trying to avoid data inconsistency, scientists have overlooked crucial insights into how female hormones impact health, fitness, and medication responses. As a result, there is limited evidence about female physiology, especially how estrogen and other sex hormones interact with exercise, muscle regeneration, and even medication use.
In a major survey conducted by the University of Copenhagen, over 150,000 women aged 45–59 participated, and 97 percent reported experiencing symptoms related to menopause. This staggering number highlights the urgent need for more targeted knowledge and treatment strategies specific to female bodies.
Rethinking Hormonal Contraceptives
Beyond menopause, Hansen has turned her attention to another frequently overlooked topic in women’s health: hormonal contraception. Roughly half of all women in Denmark use hormonal birth control, yet comprehensive research into its long-term effects on the body remains scarce.
Hansen suggests that the typical evaluation matrix for contraceptives – which usually focuses only on effectiveness and risk of side effects – should expand to include impacts on athletic performance, mood, and muscle development. She emphasizes that evidence-based guidance needs to give women a full picture, especially for elite athletes who may not realize that certain contraceptives can hinder muscle growth.
In one 2022 study involving all female elite athletes supported by Team Denmark, more than half used hormonal contraceptives. Three athletes specifically used antiandrogenic birth control pills, which are known to block testosterone. A 16-week study found that these athletes experienced less muscle gain compared to peers using more commonly prescribed pills.
Although this research is early-stage, it serves as a critical example of how hormonal interventions may alter physical outcomes. Hansen maintains that more data is necessary before generalizing findings or making public health recommendations.
New Research Projects Underway
Hansen is currently involved in several studies addressing different phases of women’s hormonal lives, from menstruation and pregnancy to menopause. One current project is investigating whether hormonal IUDs impact strength training outcomes. Another tracks physiological changes during both pregnancy and various phases of the menstrual cycle.
Perhaps the most groundbreaking of her ongoing work involves a study focused on estrogen’s role in muscle regeneration. In this project, female participants are randomly assigned to receive either estrogen supplements or a placebo. For two weeks, one of their legs is immobilized to induce muscle loss. This is followed by an eight-week rehabilitation period to monitor the effectiveness of recovery based on estrogen levels.
The research aims to determine whether women with lower estrogen experience greater muscle deterioration and require longer recovery times. These findings could influence future treatments for bedridden patients or elderly women experiencing age-related hormonal decline.
Greater Participation Needed
Despite growing interest in women’s health, Hansen notes that progress depends on participation. Many women express a desire for more research in areas like menopause and hormonal therapy, but recruitment remains a challenge. Meaningful studies require willing participants, and increasing awareness is key to advancing this field.
As attention to women’s health continues to rise both in Danish society and globally, researchers like Hansen are pushing forward to close the knowledge gap. With nearly every second woman affected by hormonal changes throughout life, filling these data voids is no longer just a scientific necessity, but a public health priority.
