Transgender Athletes Participation in Sport

Is it fair?

The greater visibility of transgender people has resulted in raised awareness surrounding the inclusion of transgender people in competitive sport.

The focus has been on the participation of transgender women in female-only sports divisions due to a concern for possible residual athletic advantage from a history of a typical male puberty.

The list of FAQs below reveals more detailed information about the debate while answering a number of the most pressing questions on the subject.

Source:, March, 2022.


Why are people concerned about transgender females competing in sports?

A possible tension exists because of the observation that, on average, cisgender boys and men have better performance outcomes in athletics than do cisgender girls and women.

The performance difference has resulted in the establishment of female-only divisions for sport participation where girls and women can safely compete and reliably win events.

The female-only divisions are a major factor to encourage greater participation of girls and women in sport with a goal of equal participation rates.

How do you determine if a transgender female has a competitive advantage vs. a cisgender (non-transgender) athlete?

To date, the only established driver for the athletic differences between men and women is testosterone, first during puberty and then ongoing.

For example, higher testosterone levels along with lower estrogen levels during a typical male puberty result in larger physical stature. In addition, there are bone formation differences that relate to hormone levels in puberty, such as the widened pelvis that develops during a typical female puberty.

Many hormone-related physical characteristics acquired during puberty are not reversed if hormone levels are changed later in life. By contrast, muscle mass, fat distribution, and red blood cell mass are among the physical characteristics that relate to an individual’s current testosterone levels. Such characteristics may indeed shift if hormone levels change.

Is it possible for a transgender child to have a hormonal advantage when participating in sports prior to puberty?

Prior to puberty there are no measurable athletic differences between boys and girls.

Epidemiologic observations that report otherwise are confounded by societal bias and by access to athletic opportunity.

Thus, there is no reason for transgender children who are prepubertal to do anything other than to participate in sport in the sex category that makes sense for them socially.

What about transgender female kids that receive puberty blockers before puberty and transition to female hormones after blockers?

There would be no reason to predict measurable athletic advantages accruing to transgender people who received puberty blockers at the onset of puberty and then hormone treatment aligned with gender identity afterward.

Are there residual athletic advantages from transgender females who went through a male puberty but are now on hormone therapy?

There is a societal bias or belief that transgender females who have gone through a typical male puberty in the past will maintain superior athletic performance, even if they are treated with gender-affirming hormones afterward.

However, existing peer-reviewed research for athleticism among transgender people is limited to small studies of sit-ups, push-ups, and medium distance running, which suggest athleticism that correlates broadly with current testosterone levels after some period of years.

Notably, the data to date do not include evidence of athletic advantage from historical puberty among transgender women while on standard testosterone-lowering regimens for multiple years.

It is possible that larger physical stature may be an advantage for some sports. It is also possible that a person with larger stature from a typical male puberty but with smaller muscle mass due to a testosterone-lowering regimen might suffer an athletic disadvantage.

What are the current guidelines for elite athletics with regards to the participation of transgender females in sport?

Because testosterone is the only established driver relevant to athletic performance that differs between men and women, the most recent elite athletic guidance has been narrowed to testosterone levels.

Guidance from the International Olympic Committee and some of the international athletic federations including World Athletics have suggested maximum testosterone levels acceptable for participation in a female-only category.

Typically, total testosterone cut points of 5 nmol/L and 10 nmol/L have been used with athletes mandated to have achieved those levels for some time period prior and to maintain those levels at all times going forward.

Such thresholds are considered to be fair to transgender women because they are well above the 1.7 nmol/L target testosterone threshold in medical treatment guidelines.

To see the current NCAA guidelines, CLICK HERE.

To see the current Olympic guidelines, CLICK HERE.

What about high school and collegiate level sports requirements?

Collegiate sport and high school sport sit between elite international level competition and sports among prepubertal children.

The National Collegiate Athletic Association mandates that transgender women be treated with hormone-lowering medical regimens for at least 1 year.

Current NCAA guidelines HERE.

What are the scientific unknowns with regards to this topic?

Much remains unknown scientifically.

For example, at what point in puberty is advantage from testosterone significant? Is there a point where such an advantage would outweigh a priority to motivate all to participate in sport of some sort?

For those who have completed puberty, what duration of testosterone-lowering treatment is sufficient to create a level playing field in a given sport?

Might there be different testosterone level cut points and treatment duration times for different sports?

And what are other considerations for specific sports?

How do the medical experts feel about the current situation?

The field of transgender medicine is filled with decisions based on fear of negative consequences rather than good scientific evidence.

We in the endocrine healthcare community have much work to do to create an evidence base to help guide decision-makers, so that choices for transgender women in sport are data driven.

In the interim, it is our responsibility to counsel those around us about the healthcare priority to encourage participation in sport and the importance of avoiding fear-driven policies.

Read more HERE.

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