US swimmer Lia Thomas, British cyclist Emily Bridges and New Zealand weightlifter Laurel Hubbard
Individual transgender athletes have been at the forefront of recent debate including US swimmer Lia Thomas, British cyclist Emily Bridges and New Zealand weightlifter Laurel Hubbard

Two current elite female runners say that trans women should compete in an open category in order to protect their sport.

One of the British athletes believes that athletes should only be allowed to compete in their biological sex.

Trans women can compete in female categories without their biological sex giving them an unfair advantage or presenting a threat of injury to other competitors if the balance of inclusion, sporting fairness and safety is not right. The governing bodies of swimming and cycling are looking at their policies.

Some argue that trans women should not compete in elite women's sport because of their perceived advantages, while others argue that sport should be more inclusive.

In recent months, the debate has gone beyond sport, even drawing comment from UK Prime Minister Boris Johnson who does not believe trans women should compete in female sporting events.

The athletes who spoke to The Sports Desk have asked to remain anonymous for fear of backlash on social media.

They were advised against speaking out by those closest to them, but felt they needed to stand up.

The only way it remains fair is if sport is kept in sex categories.

The categories are not for gender identity. There are categories for sex and the difference between the sexes.

Competition needs to be fair if it is to be meaningful.

The point of competition is to make a fair and level playing field, and the only way to do that is to have a female category and a male open category, where trans women can compete.

We need to protect women's sport.

The case of Emily Bridges is the focus of the debate.

In March, the 21-year-old was ruled ineligible to compete in her first elite women's race by the Union Cycliste Internationale. The process to rule on Bridges eligibility to race in international competition is still going on.

Bridges began hormone therapy last year as part of her gender dysphoria treatment and has now become eligible to compete in women's events because of lowered levels of testosterone.

She said she was harassed and demonised after being told she couldn't compete.

Last year, New Zealand weightlifter Laurel Hubbard became the first openly trans athlete to compete at an Olympic Games in a different sex category than the one they were born in, while in March, American Lia Thomas became the first known trans swimmer to win a national title.

athlete A said that by trying to have inclusion it excludes who the category is for.

The female category was made because women wouldn't get a look in if they played male sport.

We have seen at the Olympics last year trans women being included in the female category, and that takes away an opportunity for one woman to be called an Olympian, and that is something we all dream of.

Athlete B said that they have made great strides in encouraging women into sport.

It will be taken over by trans women who are biologically male if we exclude more women from sport.

However, this is disputed by a sports scientist. She said that trans women will never take over women's sport.

There are more than 200,000 women competing in NCAA sports in the US every year. She said that trans women make up 1% of the population and should be seen in the NCAAs every year.

11 years ago, the NCAA allowed trans women to compete. We see a few every year.

Trans women are not taking over NCAA sports 11 years after the rules went into effect. They are still under-represented.

Both athletes say that they do not want to see anyone deterred from participating at any level, but add that it is a common belief among other female athletes that trans women should not compete in women's sport.

athlete A said that she hasn't spoken to another athlete that doesn't feel the way she does.

In April, a letter signed by a group of elite female cyclists - including retired Olympians, scientists and researchers - called on the UCI to implement eligibility criteria for women based on their female biological characteristics.

The letter claimed that female athletes in the UK have shown they were willing to boycott in order for the UCI and British Cycling.

The signature of Sara Symington, head of Olympic and Paralympic programmes at British Cycling, was included in the letter.

The International Olympic Committee's stance that there should be no assumption that a trans athlete has an unfair advantage in female events was the reason why the cyclist did not sign the letter.

She said that her world titles, Olympic medals and the champion jerseys she has at home were all won in a category of people who don't try as hard as the men.

Lord Coe warned that the integrity and future of women's sport is very fragile.

What is the IOC's view?

There should be no assumption that a trans athlete has an unfair advantage in female sporting events according to the framework released by the International Olympic Committee.

It does not require trans women to suppress testosterone in order to compete in female events, but it does place responsibility on individual federations to determine eligibility criteria.

The guidance has been criticized from many corners, with the athletes saying it is very vague and not clear.

It has always been the responsibility of the federations to set their own eligibility criteria, according to the IOC's head of human rights. This hasn't changed.

The previous approach to having a set threshold of testosterone was no longer sustainable and we had to rethink how to ensure inclusion and pathway for inclusion for those with sex variation, as well as maintaining the fairness of competition.

One of the key outcomes of the consultation was that it has to be looked at on a sport-by-sport basis.

There is no suggestion in the framework that you can't exclude someone. The framework says that federation has to understand what constitutes a disproportionate advantage and that it has to be based on a thorough review of the science.

There is nothing in the framework that says she has to compete at all costs if she has demonstrated a disproportionate advantage.

We are trying to balance inclusion and fairness by having a process that allows for a fair process for all athletes in that category.

'No-one is trying to ruin women's sport' - the argument for inclusion

Charlie Martin: 'To take sport away from someone is inhuman'

One of the athletes on the other side of the debate is Charlie Martin.

The 40-year-old says she has lost physical strength and muscle mass since her transition, but says the focus on the perceived advantages that trans women hold overlooks the physical variation among all athletes.

She said that Ian Thorpe, the swimmer, had size 17 feet and hands to match, and had four flippers on the end of his limbs.

The guy won gold medals and did anyone say that was unfair?

The guy that just climbed the 14 highest mountains in the world is named Nims Purja. He was put on an oxygen machine on a bike and found that he was able to keep going even when there was no oxygen in his lungs.

If you look into sport, there are people who have advantages that people celebrate. It feels like blatant discrimination when we see a set of rules for trans women.

Martin disagrees with the view that women would dominate their sport.

I wish people would try to understand what a lived trans experience is like, and then try to understand the argument that they are trying to ruin female sport. She said no-one wants that.

Trans women just want to live a normal life and play sports. There are very few trans people in the world who are at that level, whether you are a professional athlete or just someone who wants to go and play football at your local club.

It is so easy for people to withdraw from sport when it is so toxic for trans people to try and step into it. People who love sport know the benefits. It plays a massive positive role in people's lives and to take that away from them is criminal.

Some women are in favor of the inclusion of trans athletes. Following the backlash against Thomas after he won the 500-yard freestyle NCAA title, US Olympic silver medallistErica Sullivan said she was proud to support her.

Writing in Newsweek at the time, Sullivan said: "Like anyone else in this sport, Lia has trained diligently to get to where she is and has followed all of the rules and guidelines put before her.

Lia doesn't win every time. She deserves to be celebrated for her hard-won success, not labelled a cheat simply because of her identity.

As a woman in sports, I can tell you that there are real threats to women's sports, such as sexual abuse and harassment, and a lack of women in leadership.

More reading on this subject

A major review says that trans gender inclusion, fairness and safety can't co-exist.

The IOC has new guidance on trans inclusion.

Medical experts are not happy with the IOC's guidance.

The first known trans athlete to win an NCAA swimming title is Thomas.

Lord Coe warns aboutfragile women's sport.

The governor of Florida refused to recognize the victory of Thomas.

Bridges is set to race in a women's event.

Bridges won't race in the women's National Omnium event.

Bridges still wants clarity on alleged ineligibility.

Bridges can be banned even if she meets eligibility criteria.

The British Cycling runs elite female events that no longer allow trans women to compete.

The British cyclist says female and trans athletes were let down by the governing bodies.