Biology matters more than identity in debate

LAUREL HUBBARD is a transgender New Zealand weightlifter and her participation in the Tokyo Olympics will ignite hostile debate about fairness and the rights of women in sport. The focus on one athlete is unfortunate. It should be biology, performance and sporting fairness that inform this complex debate.

Biological differences between males and females are huge, with insurmountable performance implications. A male versus female gap of even 10 per cent, as is found in running events, is so large that many thousands of men outperform the very best woman.

Many high school boys sprint faster, throw further and jump higher than women’s Olympic champions. Strength and power differences are even larger than in running. At the same weight and height, men lift 30 per cent heavier weights, and produce 30 per cent more power.

This divergence happens most profoundly at puberty. Driven by testosterone and other androgen hormones — literally, ‘male making’ — men develop stronger muscles with greater strength, on a denser and differently-shaped skeleton. Their hearts and lungs increase in size, creating greater cardiovascular capacity, and body fat is significantly reduced.

These changes are ‘performance positive’, enhancing athleticism in all but a few sports, and the result is a performance gulf, rather than gap, between typical males and females, or between Olympic-level athletic males and females. It is this difference, ranging from 10-50 per cent depending on the attribute, which necessitates the existence of a separate, protected category for women, who do not experience ‘androgenisation’.

This category separation ensures

biological sex advantages do not overwhelm the important physiological attributes that matter to sporting success in women. In turn we can celebrate Usain Bolt and Shelly- Ann Fraser- Pryce as equals, or Serena Williams and Novak Djokovic, because androgenisation doesn’t detract from the achievements of those who do not benefit from it.

The issue for sport arises when trans women enter the women’s category. The fundamental question is whether the biological differences between male sand females can be removed or even reduced significantly, if we agree fairness and safety matter.

Sports policies often require trans women to chemically reduce their testosterone levels below a certain level 12 months to be eligible to compete as women. The premise: take away testosterone, the source of the advantage, and fairness is ensured.

This leads to obvious questions, not least, is that true? What does research show? What if there is no evidence? If there’s none, should inclusion be allowed?

More than a dozen studies exist that have tracked trans women undergoing hormone suppression for at least 12 months. Bone mass and density are barely affected, muscle mass is reduced by only a small amount, and strength decreases only slightly. In short, whatever biological differences and thus sporting advantages exist initially remain largely intact.

This, fundamentally, is why Hubbard’s participation in women’s weight lifting in Tokyo is so contentious.

Ultimately, it should be principle confirmed by evidence that informs decision and policy, along with the recognition that biology rather than identity matters for sport, and that women are entitled to the fairness and safety afforded them by a category that excludes male-bodied advantage.