In line with last week’s post about doping in sport, I was having a conversation with a friend who is undergoing gender transitioning about the (noticed) effect of their hormone treatment regime on their running. Anecdotally, many people undergoing gender reassignment, particularly male-to-female, notice a profound difference in their pre-hormone treatment abilities and their current abilities. This is mostly reduced strength and power.
Much of what is known about how exogenous sex hormones affect muscle development come from women going through menopause and from men who suffer from low testosterone levels. In these studies, researchers investigated the effect that HRT had on bone density, muscle mass and fat deposition. It is from some of these studies that the hormone treatment plans have been developed for gender transition.
Testosterone is the key player
So what are the sporting advantages and disadvantages of male-to-female (MF) and female-to-male (FM) gender reassignments? The aim of the hormone treatment is to reduce the levels of endogenous hormone levels and replace with the hormones of the reassigned gender, at physiological levels, in order to feminise or masculinise physical traits.
In MF transitions a loss in bone mass density and lean muscle mass, as well as the redistribution of fat, in particular to thigh areas, is observed. Women do have circulating testosterone which is used by muscle cells. Therefore, the reduction in testosterone in MF transitions means that cells requiring higher levels of testosterone are reduced, leading to a loss of power and strength, plus the metabolism of energy is reduced. Thus, the converse occurs in FM transitions resulting in a marked increase in lean muscle mass and a loss of fat deposits in muscles, as well as increased power due to the increase in muscle protein and energy consumption.
In many of the HRT studies mentioned earlier, it was shown that strength, power and muscle mass could be improved upon exercise, regardless of whether it was increasing testosterone or HRT for menopausal women. This led the authors to conclude that transitioning individuals have positive benefits from performing daily exercise.
The Olympics and the ‘Fem card’
During my research into this post, I stumbled on some interesting articles regarding transgender athletes, the definition of gender and the Olympics.
Up until the 1990s, female athletes had to prove that they were in fact women, and were issued a document ( also known as the ‘Fem card’) certifying that they were in fact a woman. This was based on the assumption that women were thought to be physically inferior in comparison to men, and therefore someone who had transitioned from male-to-female could have a competitive advantage over other female athletes. Interestingly, FM transitions were not even regarded in the context of ‘fair play’ owing to the line of thinking that the FM individuals would not have a competitive advantage because they had been born a woman, despite the fact that they were taking testosterone at higher than physiological levels.
Initially, women were required to prove that they were in fact female based on a visual inspection. This practice was discarded in the 1960s owing to the fact that it was humiliating and invasive. Following the invention of the polymerase chain reaction (PCR), a laboratory technique that allows nucleic material to be amplified, athletes were proven to be female based on chromosomal markers i.e. the fact that females have two X chromosomes and men have XY. Problems arose when it became apparent that some female athletes suffered from genetic disorders meaning that outward appearances and other physiological markers identified them as women, but at the genetic level they were XXY. They were, therefore of neither gender.
Gender and ‘fair play’
In 2003, the IOC developed policies regarding the definition of gender and ‘fair play’. Part of this was to incorporate the fact that some effects of testosterone cannot be reversed, for example height, which may lead to a slight competitive advantage. However, it was also to be more inclusive and to redeem themselves from the gender tests of the past. These policies mean that anyone who underwent the transition process before or at puberty is considered to be of their reassigned gender. Individuals who underwent transitioning in adulthood must be 3 years post initiation of their treatment before they can compete as their reassigned gender.
Finally, while it seems that in a MF transition, the loss of testosterone is a disadvantage, scholars acknowledge that sporting ability also depends on an individual’s genetic makeup. For example, how they metabolise energy, the predominant muscle fibres, cardiovascular health, and lean muscle mass. What this means is that while there are changes in a person’s sporting ability during the transition, ‘natural athleticism’ accounts for a lot!
Hembree et al.Endocrine Treatment of Transsexual Persons:An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism (2009) 94:9, 3132-3154
Reeser, J. Gender identity and sport: is the playing field level? Br J Sports Med (2005) 39:10 695-699 doi:10.1136/bjsm.2005.018119
Pöllänen, Eija, et al. Intramuscular sex steroid hormones are associated with skeletal muscle strength and power in women with different hormonal status. Aging cell 14.2 (2015): 236-248.
Sullivan, Claire F. Gender verification and gender policies in elite sport eligibility and “fair play”. Journal of Sport & Social Issues 35.4 (2011): 400-419.
Gooren, L. J., and M. C. Bunck. Transsexuals and competitive sports. European Journal of Endocrinology 151.4 (2004): 425-429.