Sex in Sport

Effects of Moderately Increased Testosterone Concentration on Physical Performance in Young Women

Objective To investigate the effects of a moderate increase in serum testosterone on physical performance in young, physically active, healthy women.

Methods A double blind, randomised, placebo controlled trial was conducted between May 2017 and June 2018 (ClinicalTrials.gov ID: NCT03210558). 48 healthy, physically active women aged 18–35 years were randomised to 10 weeks of treatment with 10 mg of testosterone cream daily or placebo (1:1). All participants completed the study.

The primary outcome measure was aerobic performance measured by running time to exhaustion (TTE). Secondary outcomes were anaerobic performance (Wingate test) and muscle strength (squat jump (SJ), counter movement jump (CMJ) and knee extension peak torque). Hormone levels were analysed and body composition assessed by dual energy X-ray absorptiometry.

Results Serum levels of testosterone increased from 0.9 (0.4) nmol/L to 4.3 (2.8) nmol/L in the testosterone supplemented group. TTE increased significantly by 21.17 s (8.5%) in the testosterone group compared with the placebo group (mean difference 15.5 s; P=0.045).

Wingate average power, which increased by 15.2 W in the testosterone group compared with 3.2 W in the placebo group, was not significantly different between the groups (P=0.084). There were no significant changes in CMJ, SJ and knee extension.

Mean change from baseline in total lean mass was 923 g for the testosterone group and 135 g for the placebo group (P=0.040). Mean change in lean mass in the lower limbs was 398 g and 91 g, respectively (P=0.041).

Conclusion The study supports a causal effect of testosterone in the increase in aerobic running time as well as lean mass in young, physically active women.

Hirschberg AL, Elings Knutsson J, Helge T, et al. Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study. British Journal of Sports Medicine 2020;54:599-604. Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study
 
[OA] Transgender Women in The Female Category of Sport: Is the Male Performance Advantage Removed by Testosterone Suppression?.

Sex dimorphism starts during early embryogenesis and is further manifested in response to hormones during puberty. As this leads to physical divergence that is measurably different between sexes, males enjoy physical performance advantages over females within competitive sport.

While this advantage is the underlying basis of the segregation into male and female sporting categories, these sex-based categories do not account for transgender persons who experience incongruence between their biological sex and their experienced gender identity. Accordingly, the International Olympic Committee determined criteria by which a transgender woman may be eligible to compete in the female category, requiring total serum testosterone levels to be suppressed below 10 nmol/L for at least 12 months prior to and during competition. Whether this regulation removes the male performance advantage has not been collectively scrutinized.

Here, we aim to review how differences in biological characteristics between biological males and females affect sporting performance and assess whether evidence exists to support the assumption that testosterone suppression in transgender women removes the male performance advantage.

In this review, we report that the performance gap between males and females amounts to 10-50% depending on sport. The performance gap is more pronounced in sporting activities relying on muscle mass and strength, particularly in the upper body. Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 1 year of treatment.

Thus, current evidence shows that the biological advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations may therefore be compelled to reassess current policies regarding participation of transgender women in the female category of sport.

Hilton, E.N.; Lundberg, T.R. Transgender Women in The Female Category of Sport: Is the Male Performance Advantage Removed by Testosterone Suppression?. Preprints 2020, 2020050226 (doi: 10.20944/preprints202005.0226.v1). Transgender Women in The Female Category of Sport: Is the Male Performance Advantage Removed by Testosterone Suppression?
 
Is testosterone responsible for athletic success in female athletes?

Background: The aim of this study was to determine the interrelationship between the resting serum testosterone (T) levels of female athletes from different types of sporting events and their athletic success.

Methods: The study involved 599 Russian international-level female athletes (95 highly elite, 190 elite, and 314 sub-elite; age: 16-35 years) and 298 age-matched female controls. The athlete cohort was stratified into four groups according to event duration, distance, and type of activity: 1) endurance athletes, 2) athletes with mixed activity, 3) speed/strength athletes, and 4) sprinters. Athletic success was measured by determining the level of achievement of each athlete.

Results: The mean (SD) T levels of athletes and controls were 1.65 (0.87) and 1.76 (0.6) nmol/L (P=0.057 for difference between groups) with ranges of 0.08-5.82 and 0.38-2.83 nmol/L in athletes and controls, respectively. T levels were positively associated with athletic success in sprinters (P=0.0002 adjusted for age) only. Moreover, none of the sub-elite sprinters had T>1.9 nmol/L, while 50% of elite and highly elite sprinters had T>1.9 nmol/L (OR=47.0; P<0.0001).

Conclusions: Our data suggest that the measurement of the serum T levels significantly correlates with athletic success in sprinters but not other types of athletes and in the future may be useful in the prediction of sprinting ability.

Ahmetov II, Stepanova AA, Biktagirova EM, et al. Is testosterone responsible for athletic success in female athletes? [published online ahead of print, 2020 Jun 29]. J Sports Med Phys Fitness. 2020;10.23736/S0022-4707.20.10171-3. doi:10.23736/S0022-4707.20.10171-3 https://www.minervamedica.it/en/journals/sports-med-physical-fitness/article.php?cod=R40Y9999N00A20062901
 
Effects of Moderately Increased Testosterone Concentration on Physical Performance in Young Women

Objective: To investigate the effects of a moderate increase in serum testosterone on physical performance in young, physically active, healthy women.

Methods: A double blind, randomised, placebo controlled trial was conducted between May 2017 and June 2018 (ClinicalTrials.gov ID: NCT03210558). 48 healthy, physically active women aged 18-35 years were randomised to 10 weeks of treatment with 10 mg of testosterone cream daily or placebo (1:1). All participants completed the study.

The primary outcome measure was aerobic performance measured by running time to exhaustion (TTE). Secondary outcomes were anaerobic performance (Wingate test) and muscle strength (squat jump (SJ), counter movement jump (CMJ) and knee extension peak torque). Hormone levels were analysed and body composition assessed by dual energy X-ray absorptiometry.

Results: Serum levels of testosterone increased from 0.9 (0.4) nmol/L to 4.3 (2.8) nmol/L in the testosterone supplemented group. TTE increased significantly by 21.17 s (8.5%) in the testosterone group compared with the placebo group (mean difference 15.5 s; P=0.045).

Wingate average power, which increased by 15.2 W in the testosterone group compared with 3.2 W in the placebo group, was not significantly different between the groups (P=0.084). There were no significant changes in CMJ, SJ and knee extension.

Mean change from baseline in total lean mass was 923 g for the testosterone group and 135 g for the placebo group (P=0.040). Mean change in lean mass in the lower limbs was 398 g and 91 g, respectively (P=0.041).

Conclusion: The study supports a causal effect of testosterone in the increase in aerobic running time as well as lean mass in young, physically active women.

Hirschberg AL, Elings Knutsson J, Helge T, et al. Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study. Br J Sports Med. 2020;54(10):599-604. doi:10.1136/bjsports-2018-100525 https://bjsm.bmj.com/content/54/10/599
 
[OA] Caster Semenya, Athlete Classification, and Fair Equality of Opportunity in Sport

According to the Differences of Sex Development (DSD) Regulations of the International Association of Athletics Federations (IAAF), Caster Semenya and other athletes with heightened testosterone levels are considered non-eligible for middle distance running races in the women's class.

Based on an analysis of fair equality of opportunity in sport, I take a critical look at the Semenya case and at IAAF's DSD Regulations. I distinguish between what I call stable and dynamic inequalities between athletes.

Stable inequalities are those that athletes cannot impact or control in any significant way such as inequalities in biological sex, body size and chronological age. Dynamic inequalities, such as inequalities in strength, speed and endurance, or in technical and tactical skills, can be impacted and to a certain extent controlled by athletes.

If stable inequalities exert significant and systematic impact on performance, they provide a rationale for classification. If high testosterone level is an inborn, strong and systemic driver of performance development, inequalities in such levels can provide a rationale for classification.

As is emphasised by the Court of Arbitration for Sport (CAS), this leads to a dilemma of rights: the right of Semenya to compete in sport according to her legal sex and gender identity, and the right of other athletes within the average female testosterone range to compete under fair conditions. I conclude with providing conditional support of the CAS decision in the Semenya case and of IAAF's DSD Regulations.

Loland S. Caster Semenya, athlete classification, and fair equality of opportunity in sport [published online ahead of print, 2020 Jul 20]. J Med Ethics. 2020;medethics-2019-105937. doi:10.1136/medethics-2019-105937 https://jme.bmj.com/content/early/2020/07/17/medethics-2019-105937
 
Trans-Athletes in Elite Sport: Inclusion and Fairness

We support gender equality and freedoms in cases in which 'like equals like'. Such inclusion is central to a progressive society. However, inclusion could potentially conflict with fairness in cases concerning transgendered athletes in elite sport. Accepted science regarding male and female physiology suggests that transwomen have an advantage over their cisgendered counterparts.

This advantage stems from relatively high testosterone levels and prior male physiology of transwomen. Conversely, transmen who wish to compete in the men's division may be disadvantaged in comparison with cismen. Hence, while inclusion supports transwomen and transmen competing in the division that matches their gender identity, this may not satisfy the principle of fairness.

We reason that transwomen and cismen are not only advantaged, but unfairly advantaged, and propose that the gender binary in elite sport should be replaced with a nuanced algorithm that accounts for both physiological and social parameters. As the algorithm would be applied to all athletes, it would be both inclusive and fair.

Anderson L, Knox T, Heather A. Trans-athletes in elite sport: inclusion and fairness. Emerg Top Life Sci. 2019;3(6):759-762. doi:10.1042/ETLS20180071 Trans-athletes in elite sport: inclusion and fairness
 
Unisex Sports: Challenging the Binary

This paper addresses some problems arising with respect to the male/female binary division that has traditionally been central to most sports. One strategy for dealing with this problem is to remove the binary and allow athletes of different sexes to compete together.

Firstly, since there are different ways of ‘mixing’ athletes together, a distinction between two major kinds will be introduced: ‘mixed sports’ (sports with an allocated position for a number of males and females in a team, which retains the binary) and ‘unisex sports’ (sport participation of all athletes together based on merit, with no need to distinguish between sexes).

Secondly, I shall offer a strategy for the modification of existing sports and the creation of new sports that would accommodate athletes of different sexes in ‘unisex sports’. This means paying attention to how sports are constructed and which abilities/skills they test.

For unisex sports, two kinds of logic are suggested: ‘balance of abilities/skills logic’ proposes that we should seek a balance of what we presently understand as female and male (together with sex-neutral) abilities/skills to be included in the sporting challenge; whereas ‘complexity logic’ proposes the creation or modification of sports so as to test for a wider spectrum of abilities/skills.

Martínková I. Unisex sports: challenging the binary. Journal of the Philosophy of Sport 2020;47:248-65. https://doi.org/10.1080/00948705.2020.1768861
 


Athletics South Africa has decided to continue its pursuit for justice against the sad ruling by the Swiss Federal Tribunal on the discriminating rules of World Athletics regulating participation of women in athletics. The Swiss ruling upholds the IAAF eligibility regulations for female classification (Athletes with Differences in of Sex Development), commonly known as the DSD Regulations. The ruling dismissed the appeals lodged by Athletics South Africa and Caster Semenya against the award announced on 30 April 2019 by the Court of Arbitration for Sport (CAS).

...
 
Gender, Testosterone, and Sport

The incidence of transgender individuals is estimated to be one in 10 000 to 15 000 sex-assigned males (for those designated male at birth who identify as female, also known as transwomen) and one in 30 000 to 40 000 sex-assigned females (for those designated female at birth who identify as male, also known as transmen). There is no published literature ascertaining the incidence of transgender athletes.

Appropriate terminology is always important but particularly salient here. Sex and gender are often used interchangeably but have, in fact, quite different meanings. Sex is assigned at birth, typically based on genital phenotype. Gender is socially, culturally, and personally defined. Gender identity is a person’s internal sense of their gender. Cisgender individuals’ gender identity is the same as their sex assigned at birth, whereas transgender individuals’ gender identity differs from their sex assigned at birth. Transsexual is an older term and is considered by many in the transcommunity to be pejorative.



More research to quantify the effects of testosterone on athletic performance should be conducted. This is important not only for transgender athletes, but also for all athletes, to create guidelines based on scientific evidence. To be equitable, the policies should also be consistently applied to all athletes because many cisgender male and female athletes have variations in endogenous hormone levels.

Currently, males with higher end levels of endogenous testosterone are not restricted from participation, nor are athletes with other highly touted advantages such as large arm-to-torso ratios or high V̇O2 max. In fact, these physiological and anatomical differences that contribute to athletic success are lauded in the press.

An alternative consideration would be to categorize able bodied athletes in a similar manner as that used for adaptive and para-athletes, who are classified by defined physical capabilities, or in sports such as wrestling and boxing, that are classified by weight. Rather than classifying athletes into a male or female category, testosterone levels and possibly anthropomorphic or physiological measurements could be used if research supports its efficacy.

To be used constructively, the potential ethical concerns and subjective bias of different classifications would need to be mitigated. This approach is likely to be considered as revolutionary and controversial and, if considered, would need to be soundly based on extensive research. It would have implications for not just transgender athletes, but cis athletes as well.

Rizzone KH. Gender, Testosterone, and Sport [published online ahead of print, 2020 Sep 15]. Clin J Sport Med. 2020;10.1097/JSM.0000000000000849. doi:10.1097/JSM.0000000000000849 Gender, Testosterone, and Sport : Clinical Journal of Sport Medicine
 
A Local Criterion of Fairness in Sport: Comparing the Property Advantages of Caster Semenya and Eero Mäntyranta with Implications for The Construction of Categories in Sport

This paper aims to bring a novel approach to the discussion of unfair advantages in sport by looking for a local criterion of fairness instead of a universal criterion. A local criterion of fairness would not solve the general dispute over what counts as an unfair advantage, but it would be beneficial in evaluating specific cases and could guide further discussion about them.

We seek a local criterion of fairness by comparing the specific property advantages of Caster Semenya and Eero Mäntyranta. South African Semenya is a middle-distance runner whose right to compete in the female category has been challenged owing to her assumed difference of sex development and related high level of testosterone. Finnish Mäntyranta was a cross-country skier with an exceptionally high haematocrit level. We examine whether there is a relevant difference between their advantages that would justify treating the athletes differently.

We propose that the criterion 'not attainable by other athletes in the same category' could stand as a local criterion of fairness under certain conditions. However, its proper application requires further discussion on how to justify categories in sport.

Camporesi S, Hämäläinen M. A local criterion of fairness in sport: Comparing the property advantages of Caster Semenya and Eero Mäntyranta with implications for the construction of categories in sport. Bioethics. 2020 Nov 12. doi: 10.1111/bioe.12827. Epub ahead of print. PMID: 33184909. https://onlinelibrary.wiley.com/doi/10.1111/bioe.12827
 

Attachments

[OA] Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage

Key Points

Given that biological males experience a substantial performance advantage over females in most sports, there is currently a debate whether inclusion of transgender women in the female category of sports would compromise the objective of fair and safe competition.

Here, we report that current evidence shows the biological advantage, most notably in terms of muscle mass and strength, conferred by male puberty and thus enjoyed by most transgender women is only minimally reduced when testosterone is suppressed as per current sporting guidelines for transgender athletes.

This evidence is relevant for policies regarding participation of transgender women in the female category of sport.


Males enjoy physical performance advantages over females within competitive sport. The sex-based segregation into male and female sporting categories does not account for transgender persons who experience incongruence between their biological sex and their experienced gender identity.

Accordingly, the International Olympic Committee (IOC) determined criteria by which a transgender woman may be eligible to compete in the female category, requiring total serum testosterone levels to be suppressed below 10 nmol/L for at least 12 months prior to and during competition. Whether this regulation removes the male performance advantage has not been scrutinized.

Here, we review how differences in biological characteristics between biological males and females affect sporting performance and assess whether evidence exists to support the assumption that testosterone suppression in transgender women removes the male performance advantage and thus delivers fair and safe competition.

We report that the performance gap between males and females becomes significant at puberty and often amounts to 10–50% depending on sport. The performance gap is more pronounced in sporting activities relying on muscle mass and explosive strength, particularly in the upper body

Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 12 months of treatment.

Thus, the muscular advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations should consider this evidence when reassessing current policies regarding participation of transgender women in the female category of sport.

Hilton, E.N., Lundberg, T.R. Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage. Sports Med (2020). https://doi.org/10.1007/s40279-020-01389-3

 
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