Rugby findings on athlete biology set to shake up international sports

Earlier this year, World Rugby caused somewhat of a stir when its draft proposals to ban biological men from playing at the top level of women’s rugby were reported by The Guardian. The proposals were of particular interest because they were in sharp contrast to the rules of the International Olympic Committee (IOC), which has loosened its requirements to focus on athletes’ testosterone levels. World Rugby was also the first international sporting federation to indicate such a move, which led to immediate criticism from some quarters that the proposals were “harmful” despite the fact the they were aimed at safeguarding players’ health.

Earlier this month, World Rugby released the final version of its Transgender Guidelines document, confirming that biological men would be barred from playing at the top level of women’s rugby. The reasoning was based on two primary factors that had emerged from the scientific research into the issue: first, the unacceptable risk of injury to female players; and second, the existence of significant performance advantages.

Rugby is a full-contact sport that involves frequent collisions, and there are particular risks to players’ heads and necks. The nature of the sport means that injuries are frequent and, very sadly, they occasionally result in life-altering disabilities. With that in mind, the conclusion reached by World Rugby should not be entirely surprising. However, the pioneering research that underpinned the final decision was compelling and is likely to send shockwaves throughout the sporting world.

The research set out not only the distinct biological advantages that men had over women (including increases in muscle density and increased heart and lung size), but went on to consider the effect that these advantages had in athletic performance. The research showed that men generally had a 30-60 percent advantage over women in strength, around a 33 percent advantage in terms of power and a 10-15 percent advantage in running speed. Even after taking testosterone suppressants (as per the IOC guidelines), the performance advantages remained significant, with only a fractional reduction in the males’ existing ability.

Notably, World Rugby said that it simply was not viable to assess individuals on a case-by-case basis because there was no sensible way of assessing the physiological variables against an agreed standard. Their conclusion was that a focus on androgen/testosterone-driven physiological changes “theoretically replaces the need for traditional categories [of] men’s and women’s sport, to the detriment of all women’s participation in sport.”

Ross Tucker, the science and research consultant for World Rugby, acknowledged the “struggle” in considering the many aspects involved in the decision, saying that it was not possible to balance inclusion, safety and fairness. He emphasized that the organization was committed to an annual review of the policy and would formally review the guidelines every three years. But in affirming his belief in the final decision, he said, “for now, every piece of evidence points one way, and we went that way.”

Despite the compelling evidence presented by World Rugby, some national rugby bodies have indicated that they will not be following the guidance at the domestic level — the most influential being the English Rugby Football Union. An RFU statement reiterated its commitment to “LGBTQ+ inclusion” and suggested that further scientific evidence was required before it would consider implementing the recommendations.

There was a haughty tone to the RFU’s response, not least because sexual orientation is irrelevant to the guidelines, but also because nothing was provided by way of contrary studies. Indeed, Word Rugby’s findings were so stark that they will likely prompt other international sporting federations to undertake their own reviews sooner rather than later. One particularly eye-catching statistic in the scientific evidence was a 160 percent performance advantage in the activity of “punching” for men over women, which begs the question of why boxing and mixed-martial-arts federations have yet to take any action.

Perhaps World Rugby’s findings will mark a turning point in an increasingly fraught debate. Prominent female athletes, including tennis legend Martina Navratilova, have become more outspoken in their view that it is inherently unfair to let biological men compete in women’s sport. And although the IOC rules on the issue have been repeatedly diluted over the past 10 years to enable biological men to compete in several categories, there are murmurings that things might change after the Tokyo Olympics in 2021.

World Rugby is to be congratulated for going where the evidence led rather than pandering to an ideological lobby where slogans take precedence over science. In prioritizing the safety of women at the pinnacle of the game, it set a clear example for other federations to follow to avert real harm, as well as ensuring the viability of women’s sport. As further scientific studies continue to shed light on the area, we may wonder how any other conclusion was ever seriously contemplated.

Laurence Wilkinson is a human rights lawyer with Alliance Defending Freedom (@AllianceDefends).