The decision by the international swimming body to ban trans women from female competition is massive.

As far as I can tell, this is the first sports body to outright ban trans women from competing against biological women.

Other sporting bodies have tried to do it by mucking around with testosterone rules, but this the first decision where they simply say no.

I’ve got to applaud it.

That can’t have been an easy decision to make because no one wants to be unkind to trans women.

No one wants to exclude them.

But there are two competing values here: inclusion and fairness.

I honestly believe most good people want to include trans women but they also want to be fair.

And these two values inclusion and fairness clash with each other when it comes to trans women in sports because including trans-women is not fair on biological women.

Who are we kidding? It’s not a fair competition. Male bodies are stronger than female bodies.

Dave Gerrard is a former Olympic swimmer, an Emeritus Professor of Sports Medicine at Otago University and the vice-chairman of the Sports Medicine Committee for the international swimming body and he thinks it’s not fair on women.

As he points out, 14 and 15 year old boys in the states are running times and in one case swimming times that would win Olympic gold medals by the best women athletes in the world.

I worry about the other parts of this decision.

FINA - the governing body - is setting up an open category for trans women to compete in but I worry that there won’t be enough athletes to make it actually work and I really want it to.

And FINA will allow trans women to compete if they transition from male to female before age 12 and I worry that will incentivise some kids to do it at that age and that’s way too early to make lifelong decision like that.

But as for having the courage to say no trans women cannot compete against mostly weaker and slower women? No doubt that’s the right call and a brave one.