What Science Has To Say About Transgender Athletes

With athletes such as Caster Semenya and Dutee Chand excluded from athletic competitions on the basis of gender identity, concerns regarding trans womens’ participation in athletic competition continues to surface in conversation and has fostered polarizing sides (“Dutee Chand on Semenya Ruling”).

There has been an outcry concerning violations of trans rights, and equity in an athletic environment with blurring of gender binaries. Concerns regarding unfair biological advantages in trans women have fueled the opposition and raised questions.


While the physiological advantages which arise from male development supposedly provide trans women with an advantage over their cisgender competitors, which fails to foster a level field, ultimately transgender athletes are entitled to respect for their intrinsic value as human beings and should not be ostrasized from professional competitions on the sole basis of their identity. Therefore, trans women deserve the right to compete in athletic environments as long as the physiological requirements in athletic committees are consistently met.  

As of 2016 trans women are required by the International Olympic Committee to maintain testosterone levels under 10 nanomoles/L for one year to be eligible (Pavitt). Whether this hormonal treatment cancels out biological advantages developed through male puberty is of major concern and has been championed by those who aim to exclude trans women.

On Good Morning Britain, former Olympic swimmer Sharon Davies stated, Quote(s): “If you go through puberty you have all the benefits of having a male body, and even if you transition and reduce your testosterone, you’re still gonna have those benefits, you’re gonna have the bone structure, the slightly bigger heart, more red blood cells, so therefore a female athlete competing with a transgender female is always gonna be at a disadvantage” (“Do Trans Athletes Have an Advantage”).

Tweet By Sharon Davies regarding trans women setting records in women’s powerlifting.

 Testosterone increases strength and size of muscles and bone structure (“Testosterone, What it Does and Doesn’t Do”). So does the yearlong hormonal treatment truly reduce the magnitude of these benefits? 

In 2019, A study conducted by scientists within the Journal of Clinical Endocrinology and Metabolism published by Oxford Academic found that yearlong testosterone therapy did not effectively reduce strength levels and muscle density of trans women (Wiik et al.).

(Wiik et al.)

“Thigh muscle volume increased (15%) in TM, which was paralleled by increased quadriceps cross-sectional area (CSA) (15%) . In TW, the corresponding parameters decreased by –5% (muscle volume) and –4% (CSA), while density remained unaltered.“ The changes in trans women regarding anterior, posterior, and total thigh strength are modest compared to those of trans men (Wiik et al.).

 According to results of this SPECIFIC study transwomen are not experiencing significant changes as a result of this therapy, fostering unfair advantages in sports. This highlights why sports are sex segregated to begin with, to elimiate discrepancies. 

In spite of claims that trans women should not be allowed in professional sports on the basis of identity and modest changes in muscle, other studies have found significant performance changes. 

In 2015 Medical Physicist Joanna Harper conducted a study, published in The Journal of Sporting Cultures and Identities, of 8 trans women and their long distance running performance before and after hormone therapy (Harper 1).

“Transgender women who have undertaken testosterone suppression change from normal male testosterone levels to normal female levels, after surgery their testosterone levels are below the mean for 46,XX women. Largely as a result of their vastly reduced testosterone levels, transgender women lose strength, speed, and virtually every other component of athletic ability” (Harper 6).

(Harper 5). 

All the trans women had significantly reduced performance in long distance running. By 11.5%, from before testosterone suppression, which is the average percent difference in performance between men and women (Harper 5).

Hemoglobin is linked to endurance capabilities. “One year after testosterone suppression, hemoglobin levels in transgender women fell from 9.3 to 8.0 mmol/l. This latter number is statistically identical to the mean hemoglobin level for cisgender women” (Harper 6).

Published in European Journal of Endocrinology, scientists found within one year of gender reassignment surgery and treatment, testosterone and hemoglobin levels of trans and cis women were equal (Gooren and Bunk 427).

(Gooren and Bunk 427)

With identical hemoglobin and testosterone levels, trans women appear to be significantly affected by treatment, further affecting body composition. Hence, they do not necessarily disrupt the fabric of women’s sports and have a significant advantage- according to this study. 

Some feel that 1) the IOC policy on trans athletes polices what constitutes a woman or not, which has only ostracized trans athletes further & 2) the IOC has failed to protect their rights. 

In the publication Body and Society, in 2005, Sheila Cavanaugh and Heather Sykes from York and Toronto University stated “The IOC’s determination to provide access to fair, equitable competition for genetic women is, curiously, coming at a time when transsexuals and intersexuals are gaining access to basic civil rights…The IOC commitment to neutralizing an alleged masculine competitive advantage in women’s sport is only manifestly about the rights of genetic women. The latent anxiety is driven by a compulsive attempt to validate the age-old Western, categorical gender binary.” (Cavanaugh and Skyes 6).

In the publication, Gendered Oppression and its Intersections, Veronica Ivy, a trans Olympic cyclist and Aryn Conrad, an attorney with a PHD from Duke Graduate School with specializations in Philosophy of Biology and Metaethics stated, “Inclusion of trans athletes in competition commensurate with their legal gender is the most consistent position with these principles of fair and equitable sport….excluding legally recognized women for high endogenous testosterone values constitutes discrimination on the basis of a natural physical trait” (Ivy and Conrad 103).

The IOC’s actions have served to protect the interest of cis athletes, more than the rights of transwomen, who threaten gender binaries which define society (Ivy and Conrad 103). Because trans athletes blur these categories in sports, which heavily rely on sex segregation, they are erased. This consistent erasure only compounds the exclusion trans females experience in daily life. 

In Conclusion: 

Trans women deserve to be recognized in the field of sports as authentic competitors. To exclude trans women on the sole basis of gender identity despite certain studies proving their equity, and erase them in athletic environments as they fight for basic rights in their daily lives is immoral. That being said, much research still must be done in order to guarantee the fairest outcome for all; it is difficult to form an immediate solution based on just a few studies. To ensure that the voices of cisgender women are considered and the integrity of sport remains, the IOC could maintain the hormone requirement and after discussion with scientists, possibly identify other standards trans women could meet for eligibility; as long as this further decreases the gap between trans and cisgender athletes and is fair to both parties. 

Works Cited

Cavanaugh, Sheila L, and Heather Sykes. “Transsexual Bodies at the Olympics: The International Olympic Committee’s Policy on Transsexual Athletes at the 2004 Athens Summer Games.” Body and Society, 2 May 2005. 

“Do Transgender Athletes Have an Advantage in Female Sporting Events? | Good Morning Britain.” Youtube, 4 Mar. 2019, http://www.youtube.com/watch?v=I75kfAVF64A

Gooren, Louis J G, and Mathijs C M Bunck. Review of Transsexuals and competitive sports, European Journal of Endocrinology, 2004, docs.google.com/document/d/1Rb7ZikIldsW1L6kL5QqCM_WQtPjcYA0yjocix0-A5p0/edit#. 

Harper, Joanna. “Race Times for Transgender Athletes.” Journal of Sporting Cultures and Identities, 2015, pdfs.semanticscholar.org/1e6a/bd2c1e03ba88e9ac8da94ea1d69ff3f4878a.pdf?_ga=2.70412694.766566412.1560828260-902131801.1560828260 . 

Ivy, Conrad. “Including Trans Women Athletes in Competitive Sport: Analyzing the Science, Law, and Principles and Policies of Fairness in Competition.” Philosophical Topics, vol. 46, no. 2, 2018, pp. 103–140. JSTOR, http://www.jstor.org/stable/26927952. 

Pavitt , Michael. IOC Guidelines on Transgender Athlete Eligibility Remain in Place for Tokyo 2020, 3 Mar. 2020, http://www.insidethegames.biz/articles/1091417/ioc-guidelines-transgender-tokyo-2020

Pti. Dutee Chand on Caster Semenya’s Court Ruling: It Is Wrong. 2 May 2019, http://www.espn.com/olympics/story/_/id/26654107/dutee-chand-caster-semenya-court-ruling-wrong. 

Publishing, Harvard Health. “Testosterone – What It Does And Doesn’t Do.” Harvard Health,www.health.harvard.edu/drugs-and-medications/testosterone–what-it-does-and-doesnt-do. 

Wiik, Anna, et al. “Muscle Strength, Size, and Composition Following 12 Months of Gender-Affirming Treatment in Transgender Individuals.” Journal of Clinical Endocrinology and Metabolism, 3 Dec. 2019, academic.oup.com/jcem/article/105/3/e805/5651219 . 

Works Consulted

Aschwanden, Christie. “Trans Athletes Are Posting Victories and Shaking Up Sports.” Wired, Conde Nast, 28 Aug. 2019, http://www.wired.com/story/the-glorious-victories-of-trans-athletes-are-shaking-up-sports/. 

Blunt, Tom. “Tom Blunt: Don’t Believe Everything You Read About Trans Women In Sports.” Athlete Ally, 1 Mar. 2019, http://www.athleteally.org/tom-blunt-trans-women-sports/. 

“Home.” USA Powerlifting, http://www.usapowerlifting.com/transgender-participation-policy/. 

Huber, Martin Fritz. “The Controversy Around Caster Semenya Explained.” Outside Online, Outside Magazine, 12 July 2017, http://www.outsideonline.com/2198906/caster-semenya-debate. 

Jr., John D. Hagen. “OPINION EXCHANGE: Con: Transgender Policy Defies Common Sense.” Star Tribune, Star Tribune, 4 Dec. 2014, http://www.startribune.com/transgender-policy-defies-common-sense/284678481/. 

Knox, Taryn, et al. “Transwomen in Elite Sport: Scientific and Ethical Considerations.” Journal of Medical Ethics, Institute of Medical Ethics, 1 June 2019, jme.bmj.com/content/45/6/395. 

“Opinion | Should Trans Women Compete in Women’s Sports?” The Wall Street Journal, Dow Jones & Company, 12 Nov. 2019, http://www.wsj.com/articles/should-trans-women-compete-in-women-s-sports-11573602744. 

Petrow, Steven. “Do Transgender Athletes Have an Unfair Advantage at the Olympics?” The Washington Post, WP Company, 8 Aug. 2016, http://www.washingtonpost.com/lifestyle/style/do-transgender-athletes-have-an-unfair-advantage-at-the-olympics/2016/08/05/08169676-5b50-11e6-9aee-8075993d73a2_story.html. 

“Understanding the Transgender Community.” HRC, http://www.hrc.org/resources/understanding-the-transgender-community. 

Published by N

A high school student who is passionate about life sciences!

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