Transwomen in women's sports

Since the trans activist notion of "trans women are women" is meant literally, it follows that transwomen would be allowed to partake in women's sports. When a sports organization adheres to this notion, it poses a problem to women's sports, since the various physiological differences between the sexes allow peak-performing male athletes to significantly outperform peak-performing female athletes in most disciplines. The extent to which hormone replacement therapy (HRT) decreases the advantages of being male is yet unstudied, however it is clear that many of the changes the male body undergoes during puberty are not reversed by HRT, such as overall body size, skeletal structure, or the size of the lungs and heart.

Physiological differences

Significant physiological differences between the human sexes that might affect athletic performance include but are not limited to:

• Males weight about 15% more on average
• Males are about 15 cm (6 in) taller on average
• Males have denser and therefore more durable bones on average
• Males have stronger tendons and ligaments on average
• Males on avreage have greater total muscle mass
• Males on average have a greater ratio of muscle mass to total body mass
• Males have about 56% greater lung volume relative to body mass
• Males have larger hearts, with 10% higher red blood cell count and higher haemoglobin, meaning greater oxygen carrying capacity, although the difference is less pronounced among athletes
• Males have higher circulating "clotting factors" which allow for faster healing of wounds and higher peripheral pain tolerance

The differences in strength can be very significant. For instance, gross measures of body strength suggest that women are approximately only 50% to 60% as strong as men in the upper body, and 60% to 70% as strong in the lower body. A study of hand-grip strength found that even elite female athletes can be surpassed by a man with no athletic training. Another study of sports performance in various disciplines found that males tend to perform 5.5% to 36.8% better, depending on the discipline.

Notable transwomen in women's sports

Fallon Fox

Male transgender mixed martial arts (MMA) fighter Fallon Fox has brutalized a female opponent, Tamikka Brents, causing her to suffer a concussion, an orbital bone fracture, and seven staples to the head, in the first round. After her loss, Brents took to social media to convey her thoughts on the experience of fighting Fox: "I've fought a lot of women and have never felt the strength that I felt in a fight as I did that night. I can't answer whether it's because she was born a man or not because I'm not a doctor. I can only say, I've never felt so overpowered ever in my life and I am an abnormally strong female in my own right," she stated. "Her grip was different, I could usually move around in the clinch against other females but couldn't move at all in Fox's clinch..." Fox has won 5 out of 6 MMA fights in total.

Rachel McKinnon

Male transgender cyclist Rachel McKinnon won the women’s 35-44 sprint during the UCI Masters Track Cycling World Championships in Los Angeles, in October 2018. Third place finisher Jennifer Wagner commented that this was unfair, and later commented on Twitter that she would work on getting the rules changed, which Rachel McKinnon characterized as transphobic.

Terry Miller and Andraya Yearwood

Two male transgender high school athletes, Terry Miller and Andraya Yearwood, won first and second place in the Connecticut state championship 100-meter dash in 2018. Miller also won first place in the 200-meter dash.

Laurel Hubbard

Male transgender New Zealand weightlifter Laurel Hubbard competed at the heaviest 90 kg+ category at the 2017 Australian International & Australian Open in Melbourne, winning the gold medal. Hubbard qualified for the 2018 Commonwealth Games, but an elbow injury during the competition forced Hubbard's withdrawal from the event, while however leading the field.

Michelle Dumaresq

Canadian professional downhill mountain-bike competitor Michelle Dumaresq, who is a post-operative male-born transsexual, won the 2002 Canada Cup series, which qualified Dumaresq for the Canadian National team. In September 2002, Dumaresq co-represented Canada at the World Mountain Bike Championships. However, due to technical issues with the bike, Dumaresq only managed a 24th-place finish in the event. In 2003, Dumaresq won the 2003 Canadian National Championships and again represented Canada in the 2003 World Championships. Dumaresq repeated a Nationals win in 2004 and finished 17th at the 2004 World Mountain Bike Championships held in Les Gets, France.

At the 2006 Canadian Nationals, a protest from one of the competitors during the podium ceremonies brought attention to Dumaresq's participation in female sports. The boyfriend of second-place finisher Danika Schroeter jumped up onto the podium and helped Schroeter put on a T-shirt reading '100% Pure Woman Champ'. The Canadian Cycling Association suspended Schroeter for her actions. However, the CCA announced that Schroeter's time off the race course would be served during the off-season when it would have no impact on her.

Hannah Mouncey

On 27 May 2018, male transgender handball player Hannah Mouncey scored three goals for Melbourne Handball Club in their win over University of Queensland Handball Club for the 2018 Oceanian Open Club Championship.