Some reading
The International Olympic Committee framework on fairness, inclusion and nondiscrimination on the basis of
gender identity and sex variations does not protect fairness for female athletesInternational Olympic Committee framework on
fairness, inclusion and nondiscrimination on the basis of
gender identity and sex variations does not protect fairness
for female athletes
https://onlinelibrary.wiley.com/doi/epdf/10.1111/sms.14581
Tommy R. Lundberg, Ross Tucker, Kerry McGawley, Alun G. Williams, Grégoire P. Millet, Øyvind Sandbakk, Glyn Howatson, Gregory A. Brown, Lara A. Carlson, Sarah Chantler, Mark A. Chen, Shane M. Heffernan, Neil Heron, Christopher Kirk, Marie H. Murphy, Noel Pollock, Jamie Pringle, Andrew Richardson, Jordan Santos-Concejero, Georgina K. Stebbings, Ask Vest Christiansen, Stuart M. Phillips, Cathy Devine, Carwyn Jones, Jon Pike, Emma N. Hilton
Perspectives:
The IOC framework on fairness, inclusion and nondiscrimination on the basis of gender identity and sex variations is misaligned with current scientific and medical evidence and offers insufficient protection of fair competition for female athletes within a female category. Also, it does not adequately engage female athletes, who are primary stakeholders in their sport. Male pubertal development results in large performance advantages in athletic sports, which necessitates a female category that excludes male advantages, to ensure equal opportunity through fair competition for female athletes at all levels of sport. There is currently no evidence that testosterone suppression in transgender women can reverse male development and negate male advantages. In contrast, there is convincing evidence that the male advantage persists even when testosterone is suppressed. As a result, sports face the uncomfortable reality that the inclusion of transgender women in female sports categories cannot be reconciled with fairness, and in some instances safety, for females in athletic sports. The IOC must reconsider its framework and revise the 10 principles to reflect scientific evidence and fundamental principles of fair competition. We also recommend implementing a system to enable female stakeholders to be consulted in this matter and to have their voices heard, recognized, and valued.
There is absolutely no need for any poster to declare that others are sex fascists because they don't like that science rejects their philosophical belief. All that is ever needed is to stick with evidence.
Here is another good paper about 'testosterone'.
The New Zealand review of whether IOC 10nm/l would work to reduce advantage. It is actually rather a good explainer.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9331831/#B44-ijerph-19-09103
Transwoman Elite Athletes: Their Extra Percentage Relative to Female Physiology
Alison K Heather, Stacy T. Sims, Academic Editor and Christopher T. Minson, Academic Editor
August 2022
Abstract:
There is increasing debate as to whether transwoman athletes should be included in the elite female competition. Most elite sports are divided into male and female divisions because of the greater athletic performance displayed by males. Without the sex division, females would have little chance of winning because males are faster, stronger, and have greater endurance capacity. Male physiology underpins their better athletic performance including increased muscle mass and strength, stronger bones, different skeletal structure, better adapted cardiorespiratory systems, and early developmental effects on brain networks that wires males to be inherently more competitive and aggressive. Testosterone secreted before birth, postnatally, and then after puberty is the major factor that drives these physiological sex differences, and as adults, testosterone levels are ten to fifteen times higher in males than females. The non-overlapping ranges of testosterone between the sexes has led sports regulators, such as the International Olympic Committee, to use 10 nmol/L testosterone as a sole physiological parameter to divide the male and female sporting divisions. Using testosterone levels as a basis for separating female and male elite athletes is arguably flawed. Male physiology cannot be reformatted by estrogen therapy in transwoman athletes because testosterone has driven permanent effects through early life exposure. This descriptive critical review discusses the inherent male physiological advantages that lead to superior athletic performance and then addresses how estrogen therapy fails to create a female-like physiology in the male. Ultimately, the former male physiology of transwoman athletes provides them with a physiological advantage over the cis-female athlete.
Conclusion:
Testosterone drives much of the enhanced athletic performance of males through in utero, early life, and adult exposure. Many anatomical sex differences driven by testosterone are not reversible. Hemoglobin levels and muscle mass are sensitive to adult life testosterone levels, with hemoglobin being the most responsive. Studies in transgender women, and androgen-deprivation treated cancer patients, show muscle mass is retained for many months, even years, and that co-comittant exercise mitigates muscle loss. Given that sports are currently segregated into male and female divisions because of superior male athletic performance, and that estrogen therapy will not reverse most athletic performance parameters, it follows that transgender women will enter the female division with an inherent advantage because of their prior male physiology.
The current IOC regulations allow transwomen athletes to compete if testosterone levels have been lowered to <10 nmol/L for 12 months prior to competition. While this begins to address the advantageous effects of circulating testosterone on athletic performance, it does not take into account the advantage afforded by testosterone exposure prior to transitioning. The existing data suggests that lowering testosterone to less than 10 nmol/L for 12 months decreases muscle mass but not to biological female levels and despite the decrease in mass, muscle strength can be maintained, especially if concurrently exercising. Estrogen therapy does not affect most of the anatomical structures in the biological male that provide a physiological benefit. Hemoglobin levels are lowered by estrogen therapy, and consequently, maximum aerobic effort may be lower, but this parameter will only be manifested if testosterone levels are suppressed to levels within the biological female range and maintained for extended periods of time. Reported studies show it is difficult to continuously suppress testosterone in transgender women. Given that the percentage difference between medal placings at the elite level is normally less than 1%, there must be confidence that an elite transwoman athlete retains no residual advantage from former testosterone exposure, where the inherent advantage depending on sport could be 10–30%. Current scientific evidence can not provide such assurances and thus, under abiding rulings, the inclusion of transwomen in the elite female division needs to be reconsidered for fairness to female-born athletes.
This dailymail link discusses it.
https://www.dailymail.co.uk/health/article-12111455/The-trans-advantage-womens-sports-explained.html