• Alex Parry

Trans Athletes In Sport: A Comprehensive Scientific Overview

Updated: May 14

The topic of trans athletes in sport is at the forefront of many current debates and discussions. Not just relating to sport itself, but relating to broader topics of fairness, inclusion and equality.

Moreover, I think we can all agree that successful discussions MUST be based around factually accurate, logical thinking.

The issue we're currently facing, however, is that the discussion of trans athletes in sport is often not being handled logically or accurately.

This article will define key terms, explore the arguments both for and against trans athletes in sport, and examine key scientific literature where relevant.

First Up - Who Am I to Talk About the Topics?

Alright, before we jump in, I wanted to start with a quick bio so you know that I'm not just some armchair critic shouting things into the internet. Professionally, I'm a strength and conditioning coach, and weightlifting coach. I've worked with 2 major universities, 2 talent pathways, dozens of elite athletes, and I've run a weightlifting club. So I've got a good idea of what sport and performance look like.

I've also had the opportunity to work as the coach for an LGBTQ Powerlifting team, and actively get to know some of the awesome people within the community. So whilst I can't say that I speak for LGBTQ athletes, I can say that I have a better understanding of the issues they face than most other commentators on the topic.

Defining Key Terms

No discussion or debate can work unless all parties understand and agree on the definitions of the terms they're using. For clarity, here are some key definitions from the Oxford English Dictionary...

Sport: An activity involving physical exertion and skill in which an individual or team competes against another or others for entertainment.

Fairness: Impartial and just treatment or behaviour without favouritism or discrimination.

Equality: The state of being equal, especially in status, rights, or opportunities.

Cisgender: Denoting or relating to a person whose sense of personal identity and gender corresponds with their birth sex.

Transgender: Denoting or relating to a person whose sense of personal identity and gender does not correspond with their birth sex.

Recreational Sport Vs Professional Sport (And Tiers of Sports)

Discussions about trans athletes participation in sport often ignore the fact that there are lots of different levels of sports involvement. As a professional coach, I can tell you that the difference between recreational sport and pro sport is night and day.

Recreational athletes might train a couple hours a week, and maybe compete every now and again. Research shows (discussed in detail below) that there are various reasons why people engage in recreational sports, and that enjoyment and fitness rank especially high. Professional athletes train multiple hours per day in multiple sessions per day every day. They compete anything from 3 to 36 times per year. It is by definition their profession, they do so as a career and because they want to be the best in the world, and competitive drive ranks very high as a reason for participation.

And of course, there are various levels and tiers of sporting involvement in between these two ends of the spectrum. Recreational sport can mean anything from a few friends having a kick around, to organised multi-team leagues at various different levels of ability and commitment.

This distinction is crucial to make as we go forwards.

Why We Play Sports

This is a complex sociological discussion, which is sort of beyond the scope of this article. The important thing to note is that reasons for participation in sport include (Kerr et al. 2004, Spivey and Hritz 2013)

  • Fitness

  • Enjoyment

  • Improving mood and mental health

  • Socialising and sense of belonging

  • Skill mastery

  • Approval from peers and parents

  • Competition

So, whilst the majority discussion of trans participation tends to centre around competition, we do also need to actively consider the wider roles that sport plays within people's lives.

The Arguments Against Trans Inclusion in Sports (And their validity)

Competitive advantage and fairness

The primary argument against trans athletes in sports is centred around fairness. It is argued that trans athletes, specifically trans women, have an unfair competitive advantage over cis women.

Is It a Valid Argument?

It is important to note that there is little direct research comparing the physical performance of trans athletes against that of cis athletes. So this is an emerging area of research.

Harper et al. (2021) conducted a systematic review of the literature and found that in trans women "hormone therapy decreases strength, LBM and muscle area, yet values remain above that observed in cisgender women, even after 36 months."

Hamilton et al. (2021) concluded that "the use of serum testosterone concentrations to regulate the inclusion of trans female athletes into the elite female category is currently the objective biomarker that is supported by most available scientific literature, but it has limitations due to the lack of sports performance data before, during or after testosterone suppression." What this means is that... A) Far more research is required

B) Arguments about competitive advantage also have to be derived from physiological principles regarding things like testosterone levels, bone structure, muscle architecture etc.

Regarding point B, we know that due to these factors cis male athletes perform better in most athletic activities than cis female athletes, hence we have distinct mens'/womens' categories. The reality is that even many years post-transition, trans female athletes are still benefiting from the years spent with male physiology. An apt, if very simplified, analogy might be that if a cis female athlete took performance-enhancing drugs for 20 years, and then came off them for 3-4 years in order to compete clean, that athlete would still have derived significant benefit from training for 20 years with the enhanced physiology.

So on likelihood, I would have to conclude that yes, there is validity to this argument, and trans women do in fact possess a competitive advantage.

However, and this is a big however, whilst this competitive advantage may present an obstacle to participation in elite sport, where the stakes are incredibly high, it presents little to no obstacle in recreational sports, where the stakes are incredibly low, and play is simply for enjoyment.

Safety of Cis Female Athletes

This is actually two distinct arguments, so pay close attention...

Argument 1 is that trans female athletes are dangerous to cis female athletes in full contact sports such as boxing, mma, rugby.

Argument 2 is that trans female athletes are somehow dangerous to cis female athletes in day to day life, and should be kept out of locker rooms, changing facilities etc.

Are They Valid Arguments?

For argument 1, based on the competitive advantage and physiological differences, there could be an increased risk of injury to cis females in contact sports.

For argument 2, No. There is zero evidence to support any such conclusion. Research actually shows that trans women are far more likely to be the victims of crime than the perpetrators. (Violence Against Trans Statistics) Nearly half (47%) of trans respondents in the survey were sexually assaulted at some point in their lifetime and one in ten (10%) of the trans respondents were sexually assaulted in the past year.

Trans Female Athlete Inclusion Will Ruin/Destroy Cis Women's Sport

The argument goes that by allowing trans women to compete in sport, women's sport will become inaccessible or impossible to play, access or win for cis women.

Is It a Valid Argument?

No. There is zero evidence to support such a conclusion, and mathematically it's a ridiculous assertion to make.

Current estimates suggest that about 25% of women worldwide play sport. We're fast approaching 4 billion women in the world (4'000'000'000) which gives us around 1 billion women playing sport in some capacity.

Of the 4 billion women in the world, data from UK, EU and US estimates suggest that less than 1% are trans (likely FAR less in other countries) which gives us at most 40 million trans women (40'000'000) and of those trans women, research shows that although we don't have an exact percentage, significantly fewer take part in sport than cis women (Kavoura 2020, Jones 2017, HRC 2017). For the sake of argument, let's say that 12.5% of trans women participate in sport, this gives us 5'000'000 trans women in sport. 5'000'000 (trans women in sport) divided by 1'000'000'000 (cis women in sport) is 0.005%. Trans women make up 0.005% of the female sporting population, so the notion that they could somehow take over or control womens' sport is mathematically ridiculous.

Statistically, it's like arguing that a country such as Malawi or Mali is going to take over the entire world. (I did the maths)

And you might be thinking, but surely those numbers are higher in elite sport where trans women could gain a competitive advantage? That would also be incorrect. Since 2004 there have been 50,000 total olympians, and yet there has never been an openly transgender athlete. In fact, weightlifter Laurel Hubbard is set to become the first in Tokyo 2020 (or 2021 technically). That gives one trans athlete per 50'000 competitors or 0.00002%. Even less than in recreational sport.

Interesting Side Note:

It's interesting that a lot of the same people and/or organisations that have historically and even currently blocked, denigrated or ridiculed women's sport, are now the same organisations that apparently care so much about protecting it. A long history and sociology lesson is beyond the scope of this article, but if you're interested, you can take 5 minutes and start with a super basic Wikipedia search.

The Arguments For Trans Inclusion in Sports


One major argument is that of equality. Most decent folks agree that all people should have equal opportunities, and denying trans athletes the opportunity to play and engage in sports prevents this.

Is It a Valid Argument?

Absolutely, by blocking or limiting participation in sports at any level, there is an equality issue (based on the definition we clarified above)

The difficulty here is that in elite sport, allowing trans female participation may reduce the fairness of the playing field, impacting professions and careers.

However, not all sport is elite sport. In fact, the majority of sport is worldwide is recreational. A reasonable argument could be made that whilst a perfectly level playing field matters a lot in elite sport, where the stakes are incredibly high, in recreational sport it actually matters very little, because the games are being played simply for enjoyment, and so it makes far more sense to decide in favour of inclusion and equality.

Mental health

The argument is that participation in sports, and the belonging/acceptance that brings, can have profoundly positive impacts on trans athlete mental health.

Is It a Valid Argument?

There's no denying that trans men and women face elevated mental health risks. Almost half (48 per cent) of trans people have attempted suicide at least once; 84 per cent have thought about it, and more than half (55 per cent) have been diagnosed with depression at some point in their lives (Stonewall Trans Mental Health Survey 2012)

Studies and government policy show that social support and inclusion are key mechanisms in reducing suicide risk and improving mental health (US and UK Departments of Health 2012 and 2001) Moreover...

  • Transgender and nonbinary youth athletes have higher grades than those who don't participate in sports, and LGBTQ athletes report 20% lower rates of depressive symptoms when they engage with sports.

  • US data shows that transgender students in states with inclusive athletic policies are 14% less likely to consider suicide than students in states with no guidance (CDC 2020)

So yes, this is a valid and statistically proven argument.

A side note:

28% of transgender youth whose pronouns were not affirmed attempted suicide in the past year.


12% for those whose pronouns were affirmed.

The simple task of referring to people how they wish to be referred to reduces suicide risk by 16%.

Is the Debate ACTUALLY about sport?

If trans female athletes make up 0.0002 to 0.005% of the female sporting population, why is so much time, energy and media attention being drawn to them?

If we look at basic principles that humans tend to agree on, individual rights and freedoms are pretty high up there.

Realistically it doesn't matter how someone is living their life so long as it's not actively causing harm to someone else.

Pretty simple stuff. So when transphobic people (including politicians) want to push anti-trans policies or bills, they know that they can't do so openly, because people would be more likely to call them out on it. Instead, they co-opt sport and use it as a way to push through their policies, even when they don't have any real interest or passion for sport. It simply serves as a platform through which they can push anti-trans messages in a seemingly justifiable way.

An Example

In 2020, 20 US states introduced high school transgender sports bans, one of which passed in Idaho and has since been enjoined, with the court noting an “absence of any empirical evidence” justifying the law. Already in 2021 dozens of states have introduced similar bills (Equality Federation 2021) even where lawmakers could not cite a single case of a transgender girl participating in sports. (Crary and Whitehurst 2021) Amongst this massive influx of sports-related bills, were broader bills in Texas that attempted to make assisting an under 18 with transition a form of child abuse, as well as bills that would see a doctor's medical license removed for prescribing (100% reversible) gender blocking pills to under 18's.

All from a state senator who openly said "LGBTQ people have 'unnatural sex' and promote 'abominable sex education.'" Whilst simultaneously arguing that government should stay out of personal affairs and let personal responsibility be the guide.

The above is just one example of many.

In essence, sports-related bills are being used to disguise broader anti-trans legislation, or to drum up support that can then be transferred to broader anti-trans legislation.

Mx Category - A Route Forwards?

Interestingly, the LGBT powerlifting union created a gender-neutral Mx category for competition, which has also been adopted at the local, state and regional level by USA powerlifting. So the competitions essentially have a male, female and Mx category. This is a very new idea, and more research is needed long term to see how such an idea would play out across other sports. But it's an interesting example of trans athletes actively searching for routes forward.

More than anything, this demonstrates a need for better communication with trans athletes, so that policies can be developed based on mutual understanding.

My Position Statement

Based on the current evidence, research and information available, my position statement is as follows... "At the recreational level, trans athlete inclusion within sport should be guaranteed wherever possible. This ensures equality, whilst also delivering significant mental health benefits to trans people, and creating a broader culture of acceptance. Possible exceptions that require further research are heavy contact sports such as combat and rugby, in which physiological differences might create an elevated injury risk profile.

At the professional level, more research is needed in order to inform policies, and decisions will likely have to be made on a sport by sport basis. Generally speaking, the greater the physical demands of the sport, the greater competitive advantage trans female athletes may have, and the greater the likelihood that participation would create an uneven playing field within that category It's worth noting, however, that a hard cut off at any level of sport, 'i.e. you can compete at this level but not at this one', is bound to be problematic, and for this, I do not have an answer.

Importantly, we also need to consider that undue and disproportionate focus has been placed on trans women in sport, when in reality they make up an incredibly small percentage of the sporting population (0.00002 to 0.005%) and the broader social reasons for this disproportionate focus should be critically examined."

"Lastly, a greater effort needs to be made to create open, caring dialogues with trans athletes, so that decisions can be made based on clearer understandings."

Going Forwards - Key Next Steps

1) Discuss Intelligently

Hopefully, this article has given you the scientific and sociological understanding needed to intelligently discuss trans athlete participation in sport. The world does not need another loud-mouth spouting misinformed opinions, it needs intelligent people who can speak based on supported, verifiable evidence.

2) Call out BS

If someone is misinformed, feel free to point them to this article so that they can learn more about the topic. As new research emerges, I will update this piece, so it should always be relevant to the discussion.

3) Discuss Kindly

Remember that at the heart of this debate and discussion are real people, with real feelings, thoughts and emotions. If you're unable to do this, do not engage in the discussion.

Sport, fundamentally, is something that is designed to bring people of different backgrounds together over the shared love and enjoyment of an activity. We've all got way more in common than we have separating us.

. *Intelligent, insightful and kind comments and questions are always welcome below. However, unintelligent comments that add nothing to the conversation, or hate speech, will be removed.

'Til Next Time



We're currently on version 2 of the review - following feedback I've added depth and clarification to... > The definitions of recreational vs pro sport, and the levels in between. > The reasons why people engage in sport at different levels.

> Adding discussion of Mx category.

> Acknowledging the difficulty of any hard cut-off line between levels of sporting participation.

References / Further Reading

Centers for Disease Control and Prevention, 2019 “YRBSS Data & Documentation.”

Crary and Whitehurst, “Lawmakers can’t cite local examples of trans girls in sports,” The Associated Press, March 3, 2021, available at https://apnews.com/article/lawmakers-unable-to-cite-local-trans-girls-sports-914a982545e943ecc1e265e8c41042e7

Department of Health. Preventing suicide in England: A cross-government outcomes strategy to save lives. London : Department of Health, 2012

Equality Federation, “Anti-Transgender Bills,” available at https://www.equalityfederation.org/equality-tracker/anti-transgender/ (last accessed January 2021).

Hamilton, B.R., Lima, G., Barrett, J. et al. Integrating Transwomen and Female Athletes with Differences of Sex Development (DSD) into Elite Competition: The FIMS 2021 Consensus Statement. Sports Med (2021).

Harper J, O'Donnell E, Sorouri Khorashad B, et alHow does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation. British Journal of Sports Medicine Published Online First: 01 March 2021. doi: 10.1136/bjsports-2020-103106

Human Rights Campaign, “Play to Win: Improving the Lives of LGBTQ Youth in Sports” (Washington: 2017), available at https://assets2.hrc.org/files/assets/resources/PlayToWin-FINAL.pdf;

Jones et al. (2017) “Sport and Transgender People: A Systematic Review of the Literature Relating to Sport Participation and Competitive Sport Policies,” Sports Medicine 47 (4): 701–716;

Kavoura and Kokkonen (2020) “What do we know about the sporting experiences of gender and sexual minority athletes and coaches?”, International Review of Sport and Exercise Psychology. available at https://doi.org/10.1080/1750984X.2020.1723123.

Kerr et al. (2004) Motivation and level of risk in male and female recreational sport participation, Personality and Individual Differences, Volume 37, Issue 6, Pages 1245-1253,

Spivey, L. M., & Hritz, N. M. (2013). A Longitudinal Study of Recreational Sport Participation and Constraints. Recreational Sports Journal, 37(1), 14–28. https://doi.org/10.1123/rsj.37.1.14

Stonewall Trans Mental Health Survey 2012

The Trevor Project, “National Survey on LGBTQ Youth Mental Health 2020” (New York: 2020), available at https://www.thetrevorproject.org/survey-2020/. ↩

U.S. Department of Health and Human Services (2001) National strategy for suicide prevention: Goals and objectives for action. Rockville, MD : U.S. Department of Health and Human Services.

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