In September 2021, Women in Sport, issued a response to the Sports Councils’ extensive study into the issue of trans inclusion in sport. This high-quality report included a comprehensive review of the scientific literature by an expert sports medic. It concluded that the inclusion of trans women in female categories in most sports could not be balanced with fairness, and in some sports, safety. The Sports Councils made it clear that individual sport governing bodies would need to decide their own approach and offered some examples for alternative ways to include trans women in sport. The Sports Councils have also offered ongoing support to the sports sector.
Sport is inherently physical, so the different physiologies of the sexes matters. Whilst everyone should be able to participate in sport, the Sports Councils’ Equality Group’s International Research Literature Review states “There are significant differences between the sexes which render direct competition between males and females unfair in most ‘gender-affected sports’”. The peer-reviewed scientific literature found evidence that:
On average, compared to age-matched females at any given body weight, adult males have:
- 40- 50% greater upper limb strength
- 20-40% greater lower limb strength
- 12kg more skeletal muscle mass 
Handgrip strength is often seen as a wider indicator human muscle strength and mean maximal hand-grip strength over 2,000 European young adult males and females shows:
- Female handgrip at 329 Newtons
- Male handgrip at 541 Newtons
- Highly trained female athletes still have weaker hand grip than 75% of untrained male subjects 
At full growth females are an average of 5-6 inches shorter than males. NHS 2018 states average young adult heights in England as:
- Female 5ft 4 1/2 inches
- Male 5ft 10 inches
- 50% of males are taller than some 97% of females [when plotted across population]
- A larger, stronger and denser skeleton, longer arms and legs, bigger hands and feet
- Larger hearts, greater blood volume, higher haemoglobin concentration
- Bigger lungs (adult female lungs 10–12% smaller than males of same height and age) and airway capacity than females
Impact on Sport
The muscle strength, physiological and size differences are reflected in sporting performance with males having:
- 10-12% faster times for most linear swimming and running events
- 20% better results in jumping events
- 35% greater weightlifting ability in weight-matched males and females
- 50% greater weightlifting ability if use NHS average sizes for males / females
Impacts of hormone suppression
While many sports currently try to negate male physiological advantages through transgender inclusion policies based on testosterone suppression and measurement, the review found “there is currently no direct evidence that this can be achieved by suppression of hormone levels. On the contrary, there are apparent life-long physiological advantages in the adult male, only some of which can be reversed”. The review found that:
- After 12 months: In studies which recorded the retained muscle mass/strength, there was an average of 25% residual advantage for transgender women at 12 months treatment compared with reference a group of females. After 12 months of testosterone suppression, transgender women remained 48% stronger, with 35% larger quadriceps mass compared with the control population of females.
- After more than two years of follow-up on testosterone suppression recent research citing retrospective data from military personnel in the US has shown that transgender women retain an advantage in running speed, at a residual of some 12% faster than the known normative values for females.
Women in Sport has welcomed the Sports Councils’ Equality Group Guidance and International Research Literature Review and has called for work to focus on finding alternative solutions for the inclusion of transgender women in sport. We have been calling on global sporting organisations and national governing bodies to map out a path which is based on science, and is fair and safe.
A number of World Governing Bodies have recently published new policies addressing the inclusion of trans women in sport. Whilst we welcome some of the decisions taken, we remain concerned that some policies continue to focus on current testosterone levels and at the wider implications of introducing age-limits as low as 12 years old by which individuals would have to transition. The recent decisions of World Governing Bodies will undoubtedly have an impact on elite sport in the UK, but ultimately the decisions in domestic sport lie with National Governing Bodies.
Where we can Women in Sport has been working with National Governing Bodies to support them and we are sharing our guidance about the approach we believe they should be taking. We hope that anyone implementing the guidance ensures science is at the heart of decisions, recognises there is a genuine conflict between safety and fairness and trans inclusion in most women’s sport; and listens to the voices of the people actually affected – namely natal and trans women. This issue demands courageous leadership if the integrity of women’s sport is to be safeguarded and women and girls are to have the chance after so many decades of exclusion to take part on a level playing field.
Women who play sport must be able to compete in a fair and safe sporting environment. Transgender people must be able to compete in sport too. We must recognise that categories, including the female category, exist to ensure everyone can compete, to ensure inclusion. So the focus of effort should in our view be on providing for transgender competition in a way that does not deprive natal women of the chance to take part in fair and safe sport. Sport is much-prized by individuals and by society for good reason, and our vision is that no-one should be excluded from the joy, fulfilment and lifelong benefits it provides.
 Janssen et al 2000, Handelsman et al 2018
 Bohannon et al 2019
 Leyk et al, 2007
 F Bellemare, A Jeanneret & J Couture, 2002
 World Record Snatch; 85kg Male – 187kg lift; 69kg Female – 123kg lift