Higher testosterone levels in female athletes: genetic advantage or unfair competitive edge?
This post represents my personal opinion (having worked in the genetics industry).
As a proud South African, who has spent most of my life working in and around the life sciences industry, I’ve had the opportunity to work with a number of our country’s elite achievers. I’ve seen up close the hard work and dedication that goes into winning medals and flying the flag for our country. That’s why I feel compelled to comment on the case of Caster Semenya, one of South Africa’s greatest ever athletes and the upcoming change in regulations by the International Association of Athletic Federations (IAAF)
To give some context, the IAAF recently announced the imposition of a new eligibility requirement for female athletes competing in middle distance running events, from 400m to one mile. The new regulations are due to take effect from 1 November 2018.
This move sparked a global debate around the ethical implications for athletes, such as Caster Semenya (South African middle-distance runner and Olympic gold medalist), with Differences of Sexual Development (DSD).
Caster’s situation has been the subject of controversy for many years. Voices from both sides of the argument argue passionately over whether she, and athletes like her, should be allowed to compete. What is clear however, is that Caster has been subjected to the most unpleasant and degrading public scrutiny imaginable during her many years at the top of her sport. In this post, I’ve attempted to lay out where, in my opinion, the planned changes in regulation fall down and fail all sports fans — not just supporters of Caster.
The average range of testosterone levels for females is 0.1 to 1.8 nmol/L and the average range for males is 7.7 to 29.4 m\nmol/L. The IAAF has previously detected testosterone levels in three DSD athletes of between 21–25 nmol/L. To this end, the IAAF essentially view DSD athletes, from a testosterone perspective, as males competing in female events. The basis for their standpoint is their belief that increased testosterone levels enhance athletic performance. This standpoint stems from questionable evidence put forward by Bermon and Garnier.
Their cited research suggests that increasing testosterone from 1 to 7 nmol/L in females increases muscle strength by ~25%, and haemoglobin by ~8%. Both of these aspects would be performance enhancing. Additionally, when testosterone levels in DSD athletes are reduced to 2 nmol/L — still above the average female range — their performance reduces by ~6%. To the IAAF, this signifies that DSD athletes get a performance advantage from increased testosterone and, therefore, reducing this testosterone subsequently reduces this advantage.
The regulations stipulate that to be eligible to compete in IAAF events, DSD athletes are required to meet the following criteria:
a) she must be recognised by law either as female or as intersex (or equivalent);
b) she must reduce her blood testosterone level to below five (5) nmol/Lfor a continuous period of at least six months (for example, by use of hormonal contraceptives); and
c) thereafter she must maintain her blood testosterone level below five (5) nmol/L continuously (whether she is in competition or out of competition) for so long as she wishes to remain eligible.
According to the IAAF website, female athletes who do not wish to lower their testosterone levels will still be eligible to compete in:
a) the female classification:
i) at competitions that are not International Competitions: in all Track Events, Field Events, and Combined Events, including the Restricted Events; and
ii) at International Competitions: in all Track events, Field Events, and Combined Events, other than the Restricted Events; or
b) in the male classification, at all competitions (whether International Competitions or otherwise), in all Track Events, Field Events, and Combined Events, including the Restricted Events; or
c) in any applicable intersex or similar classification that may be offered, at all competitions (whether International Competitions or otherwise), in all Track Events, Field Events, and Combined Events, including the Restricted Events.
“We want athletes to be incentivised to make the huge commitment and sacrifice required to excel in the sport, and to inspire new generations to join the sport and aspire to the same excellence,” writes IAAF PresidentSebastian Coe.
What does this mean for DSD athletes?
In theory Caster, and other athletes that don’t meet the eligibility criteria can still compete normally, for example, in non-IAAF sanctioned events. However, these events are very low tier. No athlete can earn a living, or even any form of recognition, at events without an IAAF permit. The regulation therefore acts as an effective ban, even if it isn’t an outright ban.
None of the proposed options for DSD athletes are ideal. Each option carries profound negative consequences for the women affected by this ruling. Stuck between a rock and a hard place, they must choose whether to undergo risky, invasive and unnecessary hormone replacement therapy (HRT) or give up their careers as professional female athletes. This begs the question, what do we want from our athletes? Should they be forced to alter their very hormonal makeup just to entertain within a stipulated criteria for our viewing pleasure?
Criticisms of the evidence put forward by Bermon and Garnier
Many academics voiced their concerns regarding the ethics underpinning the IAAF’s study by Bermon and Garnier. One of the main issues is that the paper did not undergo peer review (which in my opinion is quite an astonishing shortcoming) or indeed follow rigorous research standards to ensure valid results. The study is also inherently flawed, because it doesn’t correct for multiple hypothesis testing, which means that there are likely some false results in their findings.
Caldwell and Kreutzer
In their article, Case Study: Why Bad Sport Science Has Real Consequences, Aaron Caldwell and Andreas Kreutzer criticise the IAAF’s study, saying:
“Sadly, these results are entirely in line with normal practices and procedures within exercise/sport science. This very poorly done study has a direct, and personal, impact on many women’s lives. But when a field has such a low bar for statistical practice and reporting, how can we blame the authors? Instead we think this article, among other things, should be a wake up call for our field as a whole. To use an example from psychology, this is our Daryl Bem moment. We need to change the normal standards and practices towards a more open and statistically literate approach in order to prevent such egregious errors from occuring again.”
Franklin, Betancurt and Camporesi
Simon Franklin, Jonathan Ospina Betancurt and Silvia Camporesi (DNAFit’s external advisor for bioethics) published an article in the British Journal of Sports Medicine on What statistical data of observational performance can tell us and what they cannot: the case of Dutee Chand v. AFI & IAAF. Their article concludes that “the evidence put forward by Bermon and Garnier is not sufficient to sustain even draft revised regulations applying only to specific events. Our reanalysis of the available data presented by Bermon and Garnier suggests, at the very least, that further analysis is required to establish the claims made in the paper”.
They go on to explain:
“The application of statistical techniques, and interpretation of results, in such studies is not neutral, nor standardised; correlations in observational data require careful interpretation by independent researchers with access to the original data.”
Additional research on testosterone in female athletes
Ahmetov, Stepanova, Biktagirova, Semenova, Shchuplova and Bets
Ildus I. Ahmetov, Albina A. Stepanova, Elnara M. Biktagirova, Ekaterina A. Semenova, Irina S. Shchuplova and Larisa V. Bets conducted a study on testosterone in Russian female athletes. The study aimed to determine the interrelation between resting serum T (testosterone) levels of female athletes from different sporting events, and their athletic success.
The study involved 599 international-level female Russian athletes aged 16 to 35 years old. The study was made up of 95 highly elite athletes, 190 elite athletes and 314 sub-elite athletes. All participants tested negative for doping substances. The participants were stratified into four groups according to event duration, distance and type of activity (endurance athletes, athletes with mixed activity, speed/strength athletes and sprinters) as well as 298 age-matched female controls.
“Taken together, our data indicates that T is responsible for athletic success in female sprinters but not in athletes from other types of sport events such as endurance disciplines, events with mixed sport activities and speed-strength sports. Given that 38% of the variation in athletic success in sprinters can be explained by the T levels, the preliminary data suggest that the measurement of serum T (which is an inherited trait) may be used in the prediction of sprinting ability in women. Additional studies in female athletes from different groups of sport events with T levels above 10 nmol/L (with normal androgen sensitivity and after passing the clinical investigations) are needed to establish whether the hyperandrogenic state gives them competitive advantage. We also propose that current regulations on female hyperandrogenism should be reconsidered and based on the type of sport event.”
Disclosure statement
No potential conflict of interest was reported by the authors.
Note: In my capacity at DNAFit I’ve worked with both Ahmetov and Camporesi, using their excellent and proven record, as leading researchers in their given fields, to help us make our products better.
Concluding thoughts
I stand firmly in solidarity with Caster Semenya, South Africa and other DSD athletes around the world. My mission, is to use my independent resources to continue this research, helping the sport and supporting these women so that they can continue competing in elite athletic events.
Higher testosterone levels in DSD athletes is a genetic trait, just like being born with blue eyes, blonde hair or big feet
Elite athletic performance is a rare (and perfect) mix nature and nurture. One could therefore argue that all elite athletes were born with a genetic advantage in comparison to the rest of the population. Caster and other DSD athletes were born with a genetic advantage that increases their testosterone. That’s just the luck of the draw — they shouldn’t be punished for it. It’s the same as punishing Usain Bolt (retired Jamaican sprinter and three times Olympic gold medalist) for having the unique ability to achieve a fast stride cadence while also being much taller (6 ft 5 in) than everyone else.
The case of DSD athletes is of course a complicated and nuanced situation, but one thing is clear — Caster is an incredible talent. The current research which is being used to justify the change in regulations is not supported by a clear state of scientific consensus. There is (without a doubt) no basis from which to take the draconian step of artificially suppressing or holding an incredible athlete like Caster back.
I urgently ask of the IAAF to reconsider their decision, for the benefit of both elite athletes and the sport as a whole.
