Sports will not be fair anymore because of this

If it's not a fair contest it cannot be a sport. Without both parties playing under the same circumstances and rules, a sport cannot be called a sport. 

Whenever we see a case of one side taking an unfair advantage - be it doping or ball-tampering - we expect the offender to be punished. 

But this fairness that we expect sports to have is set to change now, and perhaps forever. 

Laurel Hubbard is set to become the first transgender olympian after being selected in the New Zealand weightlifting team. 

And that brings the question: do trans women have a strength advantage over biological women?

By combining gender and sex the idea of having sex categories becomes null and void. 

Without having a separate category for women, there would technically not be any women in the Olympics this time. 

The numbers show that men have a strength advantage over women and hence there are separate categories for men and women. 

Even in the 100m, one of the events with the smallest performance gap, approximately 10,000 men worldwide have personal bests faster than the current Olympic female champion, Elaine Thompson-Herah (10.70sec). 

While the smallest attainment gap between the sexes comes in running, rowing and swimming events (11-13%), this moves up to 16%-22% in track cycling, and between 29% and 34% when it comes to bowling cricket balls and weightlifting. 

The difference in punch power between men and women is a whopping 162%.

However, the International Olympic Committee (IOC) changed its rules in 2015 to allow trans athletes like Hubbard to compete in the women's category, as long as their total testosterone level in serum is kept below 10 nanomoles per litre for at least 12 months.

Increasingly though, research shows that these testosterone guidelines do not guarantee the fair competition the IOC was looking for. 

Ross Tucker, a sports scientist and expert on testosterone advantage in sport, properly explains it: "Lowering of testosterone is almost completely ineffective in taking away the biological differences between males and females." 

There is just no proof that reducing testosterone takes away the advantage of muscle mass, strength, lean body mass, muscle size or bone density. 

Despite this revelation from Drs Emma Hilton and Tommy Lundberg, the IOC has halted any further decision on the matter until after the Tokyo Olympics and has currently left it to individual sports federations to decide their own transgender policies. 

Some have been bold, others have written their policies alongside trans lobby groups without consulting women's organisations or sports scientists. 

Those questioning the narrative are accused of transphobia – as Martina Navratilova and Nicola Adams found out.

The most common argument used in favour of this inclusion is that sport is all about natural advantage and that being a trans woman is just another factor to add to a contest where no two men or women will have the same physical attributes. 

The problem with this argument, however, is that athletes don't compete according to size.

But they do protect the integrity of women's sport because the advantage gained from male puberty is so comprehensive in terms of speed, power and strength. 

Serena Williams once told David Letterman in an interview that if she were to play Andy Murray she "would lose, 6-0, 6-0, in … maybe 10 minutes". 

Male puberty and androgens give an advantage in a different stratosphere.

There are those that say this debate is pointless as trans women aren't winning everything, which is true. 

The simple explanation for that is, the trans athletes haven't been good enough in general. 

As Tucker says, "the best female cyclist will beat 99% of men, but the best men are 10-15% better". 

Whether trans women win or not – whether Hubbard wins or not – it is legitimate to question the rules that allow them in the competition, given the retained advantage. 

The American cyclist Veronica Ivy says "hang the heartache, trans women are women and should simply be able to self-identify themselves into the women's category at every level". 

This view on the matter has gotten quite a bit of popularity. 

But then it begs the question: why bother having sex categories for sport at all? Just put everyone in together. 

Trans women deserve to live their sporting lives to the fullest. Research should find a way for them to participate in female sports without advantage, or have them in a separate category. 

Until then things should be reverted back to sex-based categories – a female category and an open category that can cater for trans men who have taken testosterone, trans women and men.

Just as women and trans men can't dominate in men's sports; and men can't enter women's sport; trans women shouldn't be able to push open a door that was locked for a reason. 

It simply isn't fair.