The world of sport has been turned about at all levels over the last several years as the rise of transgender athletes has gained prominence, and asked for their fair piece of the pie. Most notably, Caster Semenya continues to be the international limelight persona in this hotly debated topic.

Castor Semenya

For those who aren’t familiar, South African track and field phenom Caster Semenya, is NOT transgender. In fact, she is what you term “intersex”, as she has traits that are synonymous to both males and females, as well as possess both an X and Y chromosome (typical of men only). In her case, she is believed to have internal testes and lack ovaries, though these are not quite fully substantiated details. Another word you’ll see tossed around is “hyperandrogenism”. Hyperandrogenism refers to high levels of endogenous androgen hormones, specifically testosterone.

Why she is important to the following rule changes, is because of her heightened level of natural testosterone, which we deem to be an unfair advantage to the characteristic female athletes she competes against. We know testosterone muscle mass (which does directly correlate to force production), increased energy production, increased bone density, and fat metabolism, especially in men. But does it significantly boost a female’s athletic ability at elevated levels? 

Research

A new study (full text here) says it certainly does, and the results make sense. Admittedly, I thought there would be a larger discrepancy in power output, but perhaps it was because the study lasted only 10 weeks. What it did show was a significant increase in aerobic performance over such a short time. Testosterone was shown to also promote an increase in muscle mass and drastically drop body fat. 

“...a moderate increase in circulating testosterone caused a significant treatment response in our primary outcome measure, running TTE [time to exhaustion], by a mean difference of 15.5 s in comparison with placebo.”

As this has harmonized with the surge of transgender participants, in particular, male to female trans athletes, its relevance is substantial.  

Equality

The outcry of non-transgender female athletes on the topic of equality, especially at the world-class level, has been extensive. Transgender athletes now only need to sign a declaration with the federation as to the gender they wish to identify as. They no longer need to also be recognized by law as female. It is certainly understandable that a natural-born female would ask for an even playing field when you work just as hard to be at the top. For them, it can be viewed as an approved performance enhancement drug they don’t have access to -- like wrestling someone two divisions up in weight class even. 

This is precisely why the International Association of Athletics Federation (IAAF) and other governing bodies have elected to attempt to find a way to, in essence, limit and control the amount of testosterone those choosing to compete in female divisions maintain during their tenure. This is in an effort to level the field of competition so that no matter the athlete, there’s relatively equal chance across the board. Only training, health, and talent should triumph. 

“Houston, we have a problem.” How in the hell do we do that?!

Leveling the playing field

For the last few years, it’s been in the spotlight and been regulated internationally, athletes are asked to reduce their blood testosterone level by taking hormone suppressing medications such as hormonal contraceptives (birth control). They are not required to undergo surgery of any type to become eligible.

On October 16, 2019, the IAAF announced new rules to help regulate a female athlete’s production of testosterone to an “allowable” level. There have been rules set forth by the IAAF and NCAA for several years now, but they have since changed. 

Prior to the new rule, female competitors were required to maintain a serum concentration of 10 nanomoles per liter (nmol/L) of blood, continuously for a 12 month period to be eligible. The new regulation is half of that. 

These rules apply to those with hyperandrogenism such as Caster Semenya. While she may not be trans, her limit exceeds that of the regulatory sanctions of the governing body. 

The Science

That’s nice if you’re a doctor but what does that mean for the layperson? The simplest way to explain this is to understand what serum is first. The serum here is in reference to blood serum. When you take a sample of blood in a tube with no anticoagulant present (so it won’t stop the blood from clotting), and you spin it really fast in a centrifuge, you’ll be left separated liquids. On the bottom, the heavier red blood cells will settle; at the top sits what we call serum. This is slightly different from blood plasma so just leave it be for now.

Your serum contains many things, including hormones! By extracting a bit of that blood serum and analyzing it, we can determine how much testosterone, for example, is contained in that sample. Thus, we get a measure of the concentration within an individual’s body. 

For reference, a normal young adult female will have a serum testosterone concentration of anywhere from 0.52 to 2.43 nmol/L. So that’s still anywhere from 2-10x more than your average woman. Granted, there are women with higher amounts of natural testosterone and, with athletes, you will see an increase due to resistance training over an average woman. So is 5 low enough? 

Who knows. In the study cited earlier, the average increase of testosterone in the 48 women was +4.3nmol/L which was shown to give a huge boost over the placebo group aerobically. Considering it affects the 400m to the mile events in track and field, and the study indicated a potential increase in performance of 7.7s and 10.8s in 1500 m and 2000 m time trials, respectively, I would say it’s at least reasonable to continue to consider policy alterations. 

We don’t really know if it’s still an even field and what good evidence there is that lowering testosterone to any particular level will make it so, especially after male to female trans athletes have undergone puberty.

We should make it clear that, by current rules, Semenya (and any other female athletes with overly high levels of testosterone) may still compete. This implies that they must choose to compete with those competitors who also have high levels of testosterone -- the men. 

Controversy

Just last year, Franklin Pierce University’s CeCe Teffler (Craig Teffler) went from barely placing at meets in the 400m hurdles as a male competitor, to becoming the Division II national champion in the women’s 100m hurdles.

June Eastwood just became the first Division I trans distance athlete. She ran 20:18.7 this past weekend in the 6k for the University of Montana. She finished second overall in a field of 200, narrowly missing first place by 1.1 seconds. This result pushes her up to the top 15 in the country as an individual. She was a state champion track athlete in high school, and before transitioning last year, was a top-end conference level competitor. 

While more is sure to come, and more needs to be researched, it’s nonetheless an interesting topic to ponder.

Do you think these regulations are fair? Do you feel we’re headed in the right direction? Should we perhaps create a third gender for competitive sporting events to keep “fair play” alive?