Triathlon has become the first British sport to ban all transgender women from participating in female competitions.

Under the new policy, trans athletes will be prohibited from entering female events at both an elite and grassroots level from the age of 12 and over.

The new policy, which comes into effect in January, will see a reclassification of the men’s category to ‘open,’ in which all trans athletes will be allowed to compete.

British Triathlon chief executive Andy Salmon told the BBC that the governing body is confident they’re doing the right thing for the sport.

“We’ve concluded that Triathlon is a gender-affected sport,” he said.

“Now, this is a legally defined term and what it means in layman’s language is that somebody born male will have a physiological advantage over somebody born female. In our sport, which involves swim, bike, and run, that will give someone a significant advantage.”

Salmon continued: “When somebody suppresses their testosterone, the science tells us that advantage is retained, and therefore, competition could not be fair.”

From the start of 2023, Triathlon will have two categories in a competitive setting where the participants are aged 12 and over: female and open. All athletes competing in the female category must be female from birth, while the open category will be available for everybody else.

The move comes just weeks after international sporting bodies, FINA and Rugby League, announced restrictions on transgender athletes in women’s events.

Swimming’s international governing body, FINA, last month said the organization would prohibit trans women from participating in female competitions if they went through male puberty, noting the physiological advantages.

Soon after, International Rugby League announced a ban on ‘male to female’ players from participating in international competitions until further research is carried out.

Salmon said he has total sympathy for transgender athletes, but the policy was about protecting the fairness of the competition.