Sports News

Transgender athletes: What do the scientists say?

The conversation around the inclusion of transgender women in women’s sport is one that has divided opinion both in and out of the sporting sphere, even drawing comment from UK Prime Minister Boris Johnson.

The debate centres around the balance of inclusion, sporting fairness, and safety in women’s sport – essentially, whether trans women can compete in female categories without their biological sex giving them an unfair advantage or presenting a threat of injury to other competitors.

BBC Sport had spoken to two scientists who offered views from opposing sides. Here is how Dan Roan and Katie Falkingham reported their views on the matter yesterday (11). Only excerpts follow:

Ross Tucker

He is a sports scientist who says the physiological differences established during puberty can create “significant performance advantages (between men and women)”.

Joanna Harper 

She is a sports scientist and is transgender herself. She studies the effects of transition on female transgender athletes.

Here, Tucker and Harper answer the key questions being debated from a scientific perspective. 

Do transgender women hold an unfair advantage over female athletes?

Harper: Advantages are not necessarily unfair, and let me use two examples, one where the advantages aren’t unfair and one where they are.

Left-handed athletes have advantages over right-handed athletes in many sports. It is perhaps most marked in fencing where 40% of elite fencers are left-handed versus 10% of the population is left-handed.

But right-handed fencers and left-handed fencers can engage in meaningful competition despite the advantages that left-handed fencers have.

However, you never put a big boxer in the ring with a little boxer, no matter how good the little boxer is. No matter how hard the little boxer works, trains, or how competitive they are, they can’t beat a big boxer. The size difference means there’s no such thing as meaningful competition between big boxers and little boxers.

So the question isn’t “do trans women have advantages?” – but instead, “can trans women and women compete against one another in meaningful competition?” Truthfully, the answer isn’t definitive yet.

Tucker: When boys reach the age of 13-14, things start to change physically and we see increased muscle mass, bone density; (it) changes the shape of the skeleton, changes the heart and the lung, haemoglobin levels, and all of those things are significant contributors to performance.

Lowering the testosterone has some effect on those systems, but it’s not complete, and so for the most part, whatever the biological differences are that were created by testosterone persist even in the presence of testosterone reduction – or, if I put that differently, even after testosterone levels are lowered.

It leaves behind a significant portion of what gives males sporting performance advantages over females.

Should transgender women be banned from women’s sport?

Tucker: The point of the women’s category is to exclude male advantage, which comes as a result of testosterone.

Until it can be shown that that advantage doesn’t persist or exist in trans women, then I would say that there’s no basis to allow trans women in.

The point of all that is that, if there were no evidence at all, I would say that an exclusion policy would be the prudent start point.

However, we do have evidence – we have 13 studies that show significant retained advantage. We have a number of other studies of males with lower testosterone levels with prostate cancer, we know what happens with training, and so I think collectively the picture is quite strong to suggest that advantages are retained.

Harper: The science is in its infancy and we are not going to have definitive answers for probably 20 years.

There are some, including the International Olympic Committee (IOC), that have said until we know (more) we shouldn’t restrict trans athletes.

What I would say is that until we know for sure, sport’s governing bodies should do the best they can with the data that exists, with the knowledge that we have today, with the understanding that any policy they create now should be subject to change once we get more data.

Should there be a separate category for transgender athletes?

Harper: In recreational sports, we should be creative; we can look at different ways of dividing. Do we need a male and female category in every case? Could we separate in other ways? Perhaps there may be cases where there is a third category that might be effective.

But the problem is if you strictly require all trans athletes to go into a trans category, then you have three categories – one with 49.5% of humanity, the other with 49.5% of humanity, and one with 1% of humanity.

Tucker: It might be that in the future – that’s where we are headed.

It would in some respects be quite a positive step, but I don’t think that the world is really ready for that, and I don’t just mean the sports world.

The one obvious problem is there would be so few athletes that I’m not sure they would be able to sustain a sporting competition or even a category that is viable.

The other problem is that there is still a lot of stigma attached to being trans and I’m not sure that trying to force or create a platform through sport would help overcome that. If anything, there might be certain barriers that are created.