Tuesday, 23 August 2016

Olympics: Some thoughts on whether 10nmol/L of Testosterone an appropriate metric and Is the right question even being asked?



The Olympics have come and gone, left nice memories and a few controversies. I think the controversy that most needs addressing is the case of “hyperandrogenic” athletes, basically female athletes with very high testosterone. To me the regulations that the International Association of Athletic Federations (IAAF) implemented (subsequently overturned by the Court for Arbitration for Sport (CAS)) are possibly an example of choosing the wrong metrics and this can have drastic consequences. Trying to exclude people without the right metrics also allows room for disgusting comments like “I am glad to be the first European and the second White” (https://www.rt.com/sport/356879-olympics-jozwik-second-white/). Furthermore, it could be that the wrong question is being asked.

First, let’s have some quick background. Women’s athletics is usually separated from men’s competition simply for questions of “fairness”, to make it a real competition. As an illustration, Paula Radcliffe’s Marathon record is one of the most outstanding records in women’s athletics (2:15:25) (although run in a mixed gender race), so far ahead of the rest (next are 2:17:18 and 2:17:43):



The men’s record is 2:02:57, the 400th men’s time is 2:07:37. Ms Radcliffe’s time would place her around 5000th fastest marathon. So it makes some sense to have separate competitions for men and women. But why am I writing this post? It gets worse than disgusting comments.

At least 4 women have had their gonads removed and their clitorises partially removed in order to be allowed to participate in IAAF (athletics ruling body) sanctioned events.

“Doctors in Nice reported in 2013 that they operated on four hyperandrogenic women, ages 18 to 21 and from rural or mountainous regions of developing countries, cutting out gonads and partially removing their clitorises. The athletes were told that surgery would most likely dent their athletic performances but allow them to continue competing, the doctors reported. They said the women were allowed to resume competition one year later.” http://www.espn.com/olympics/story/_/id/17306565/female-olympian-details-process-testosterone-level-measures-high-hyperandrogenism.

This stems from the idea that a line needs to be drawn between the 2, men and women. According to IAAF, the line is at 10nmol/L of testosterone; anything above that is considered to be in the male zone. Removing the gonads and partially removing the clitoris are designed to reduce the naturally occurring testosterone level to below the threshold.



As shown above the IAAF threshold is just at the lower range for average adult men. It would seem reasonable to set the threshold there.

However there are 2 issues that immediately spring to mind.

First, if we assume that the distribution of testosterone among males and among females are normal, there still are long tails; basically the neat minimums and maximums are not as distinct/absolute as you might think. While most men will fall into the range of around 10 to 37 nmol/L, there will be a few below 10 and a few above 37. The same concept applies to women: some below .5 and some above 2.5nmol/L. Using the minima and maxima for the average adult as the +-3 standard deviations range for a normal distribution:



Hence, instead of nicely separated groups, we are likely to have overlapping distributions; these would be out of the ordinary, exceptional people.

This brings me to my second point; what are top athletes but exceptional people?

If testosterone is indeed a major factor in explaining consistently exceptional athletic performance, this means that top athletes should have more testosterone than the average adult, and thus be concentrated towards the upper ends of the distributions for each gender. The distribution of testosterone among the athletes would not be random sampling from their respective populations, but they would be heavily biased towards members with high testosterone. In other words, the measurements for the average woman and the average man should not be used as a gauge; it would be better to use past Olympians data to set a benchmark. After all, we should be comparing with people with similar characteristics.

Would that solve the issue of metrics?

Yes and no.

I think that the metric might be acceptable (again assuming that testosterone is the main difference maker), but the question might be the wrong one. One of the issues that was raised in front of the CAS is that of discrimination against women. Basically the single threshold only affects women, men with lower or especially higher testosterone are allowed to compete among men, but women with higher levels are blocked from participating among women...

I think that the question that should be asked it not where is the line to be drawn between men and women, but there should there be more than 2 categories so that competitors are more equally matched (just like in boxing for example)? 

My conclusion in this example is that finding the right metric is critical, but also that if it is hard to find the right metric, sometimes the question itself should be revisited.

Post Scriptum: More readings on the issues surrounding hyperandrogenism:
Informative articles with historical persepctive: 
The surgeries: 
Legal Opinion:  
Details about the case brought before the CAS:  
Paper on gender and fair play, because there’s more to this question than data: 

P.P.S Opinion pieces:
Ignorance is responsible for the mess: 
Disgusting remarks: “I’m glad I am the first European, the second White”
 
A final chart from me: the best times since 2009 for the finalists of the women’s 800m at the Rio Olympics in order of finish from left to right, with runners names and ages (Data from IAAF):



I just inserted a quadratic trend; you can interpret for yourself whose performances 'show the most one-way drastic improvement over that span of time'. (Age explains why some athletes do not have that long a history of best times).



 
 

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