The differences in men’s and women’s biology mean that men competing against women in sporting competition is unfair. In contact sports, those physiological differences also put women at a greater risk of serious injury in competitions with biological men.

It is not fair or safe for women to allow biological men (no matter how they identify) to compete in women’s sport.

Why is it unfair for women?

On average, men are physically stronger than women, with 66% more upper body muscle, and 50% more lower body muscle. Being taller on average means they have an advantage in sports such as basketball and volleyball.

The average adult male has:

50% more muscle mass in his legs

75% more muscle mass in his arms

Larger heart and lungs, meaning more blood can be pumped to the body and body tissue receives more oxygen. They also have higher haemoglobin levels, which means muscles are oxygenated more quickly and efficiently.

Bigger and stronger bones – this larger and stronger skeletal structure can hold more muscle. Larger bones mean greater leverage.

A greater number of fast twitch muscle fibres – the muscle fibres that generate explosive power and rapid acceleration – beneficial in sports such as powerlifting, jumping and sprinting

Broader shoulders and larger feet and hands – giving advantage in sports like swimming, and ball sports like handball, football, volleyball and basketball.[i]

These attributes mean unfair competition for women.

Women’s anatomy – which evolved for the biological functions of gestation and childbirth – means women have less stable hips and a less efficient gait than men. [ii]

Women marathon runners have higher body fat percentages than male marathon runners.

The strongest 10% of women can only beat the bottom 10% of men in one of the most widely-used measures of strength – hand grip.

Women’s speed records in swimming, running, kayaking, long and short distance running are all about 90% of men’s speed records in these sports. In marathons, hundreds of men beat the best times in women’s marathons.

No matter how hard women athletes train, they cannot overcome those physiological advantages that give male athletes greater speed, stamina strength and size.

Doesn’t reducing testosterone levels make it fair?

No. “By puberty, testosterone and other genetic determinants have set up the male body to be a stronger athletic performer through a stronger musculoskeletal system, and an enhanced cardiorespiratory system. These effects are not reformatted by lowering testosterone.” [iii]

Transwomen athletes who do reduce their testosterone levels to qualify to compete in women’s competitions are allowed compete with testosterone levels that are between 4 and 20 times higher than the levels biological women are allowed compete with.

Shouldn’t sport be “inclusive”?

The Victorian Women’s Guild considers that “inclusiveness” for one group should not come at the expense of fairness and safety for girls and women.

Single-sex sporting competitions were set up for a very simple reason – in recognition that in sport, biology gives boys and men an unfair advantage over girls and women. There is no genuine prospect of fair or equal competition in sport because these advantageous physical attributes are significant.

Sports science research confirms this long-understood fact, so it is ironic that decisions in sporting bodies from the Olympics to Australia’s national sporting bodies have selected the one “inclusiveness” option that makes sporting participation and competition unfair and unsafe for over 50% of the population - girls and women.

The IOC decided to open women’s competition to biological men, putting “inclusion” ahead of their stated commitment to “fair play” in 2015. In making this decision, they relied on anecdotal “evidence” from Joanna Harper – a trans woman.

The IOC had not revised its decision prior to the commencement of the Tokyo Olympic Games, despite being presented with scientific evidence that makes it clear that “fair play” cannot be achieved while biological men are allowed compete in women’s competition.

The IOC has now announced a review following the outcry against male-bodied athletes being allowed compete in women’s events in the Tokyo Olympics. But their solution is for individual sports to devise their own guidelines – even though it is difficult to think of any sport where the advantages of being born male are not a threat to fairness and safety for women.

Are you concerned about transwomen (biological men) competing in women’s sport?

Two actions you can take::

You can sign Save Women’s Sport’s petition to the Australian government at this link: https://www.aph.gov.au/e-petitions/petition/EN2874/sign?fbclid=IwAR1uxyzBy1UwBSabM5gqA5brhCc9UZ-1US-Fay35utT2Px6vs98wmcGZmT0

Help put pressure on the International Olympic Committee to return women’s sport to biological women by giving your feedback to the IOC’s review. Follow this link for contact details.

What’s happening in Australia?

In October 2020, eight Australian peak sporting bodies committed to “implementing governance that supports a greater level of inclusion for trans and gender diverse people in their sports”. Most other peak sporting organisations are being lobbied to sign up to the same agreement.

All signatories oversee sports where biological men competing as transwomen have unfair physical advantages (explosive power, speed, strength, for example) that are not significantly reduced or eliminated even if testosterone levels are reduced to mandated levels.

Those signatories have committed to “inclusion” at all levels of sport, and even local sporting clubs will be pushed to include transgirls/transwomen in women’s competition, despite the obvious physical advantages.

Not one women’s sporting organisation or club was consulted about the agreement or advised of its impacts before it was signed.

This commitment was signed despite Australian discrimination legislation permitting exemptions where physical advantage would make competition unfair for women and girls.

A spokesperson for ACON (the body that negotiated these unfair changes) completely dismissed concerns that this made women’s and girl’s competition unfair, unsafe, and unequal. He provided no evidence to substantiate his claims and he did not provide any rebuttal of the mounting scientific evidence that soundly contradicts them. (Apparently in the eyes of Pride in Sport lobbyists, “inclusion” is acceptable even if it makes it unfair for over 50% of the population.)

Save Women’s Sport has been established to lobby to rectify these injustices against women.[iv]

Rugby Australia is one of the signatories, despite the international rugby body determining that it was not safe or fair for women to play in competitions with biological males who identify as transwomen.

Ross Tucker, World Rugby’s Science and Research consultant, found (through research and consultation with all sides in the debate), that sporting competition can't achieve fairness and inclusivity when it comes to transgender athletes competing in elite woman's sport. [v]

Of course, trans people should also have a right to participate in sport. But there are other strategies, including having men’s sporting organisations and clubs support the participation of gender non-conforming males in their sports and on their teams, rather than making women’s sport and competition unfair and unsafe for women. This has been successful overseas.

Why does it matter?

Any trans athlete competing in women’s competitions at the Olympic games takes a place of a woman competitor – whether they win a medal or not. And if they do win, it is at the expense of a woman competitor who has been subjected to unfair competition.

Girls and women are already under-represented in sport participation. Having to play or compete in sport made unfair or unsafe or even just uncomfortable by the inclusion of male-bodied people makes it very likely that more girls and women will be deterred from participating. They lose the benefits of sport – not only the health benefits, but benefits like camaraderie, commitment, control of emotions, teamwork for example – simply because the focus has been on “inclusion” which favours biological boys and men.

Funding is already lower for women’s sports than for men’s – fewer girls and women participating means that gap may well widen.

Girls are likely to lose educational and sporting opportunities available through sporting scholarships to male-bodied people who identify as trans because of the physical advantages of male biology.

It’s worth noting that some States and countries allow for gender identification without any medical (including hormone suppressants or other drugs) or surgical transition.

Sport’s governing bodies should be implementing strategies that maximise participation in sport. They should not adopt divisive and exclusionary policies and then demand that women and girls just accept and comply with those unfair and unsafe policies without question or dissent.


[i] https://www.savewomenssport.com/is-this-fair

[ii] Joyce, Helen. 2021. Trans: When Ideology Meets Reality. London:Oneworld Publications

[iii] https://www.stuff.co.nz/sport/other-sports/114327152/even-before-birth-genetic-building-blocks-are-giving-athletes-born-male-a-massive-advantage-over-females

[iv] https://www.savewomenssport.com/

[v] https://podcasts.apple.com/au/podcast/why-rugbys-controversial-new-transgender-guidelines/id1461719225?i=1000497073938

Further Resources

Article by Kath Deves,Co-founder and spokeswoman for Save Women’s Sport Australasia 2021.

Article by Nicola Williams, Director of Fair Play for Women 2021

https://www.2gb.com/it-really-concerns-me-top-aussie-runner-speaks-out-against-transgender-athlete/ (2019 radio program featuring Tamsyn Lewis and Jane Fleming)

Sex Based Segregation & Fairness in Sports (12 min video from 2019)