There has been increased discussion lately regarding the eligibility of transgender athletes and their participation in sporting competitions. After the whole CrossFit drama brought back memories of CrossFit’s transphobic policies that disqualified Chloie Jonsson from taking part in the CrossFit games. This incident in Connecticut in which two transgender girls swept their events at the High School Track State Championships. In addition, High School State Champion Mack Beggs still faces a lot of controversy for his double wins in the girl’s division.

The reason for all this discussion and controversy is that there is simply a lot of misinformation and overall lack of information regarding what constitutes fair play over an unfair advantage. With questions and claims being thrown around that are based on little research or willful ignorance with little regard of the fact that we’re just talking about human beings. With such inconsistent and uneducated out there as well as inconsistent policy. It is easy to get lost in the sea of it all and end up even more confused than before.

So, before we move on, let’s clarify things…


Transgender Male- A person assigned female at birth who identifies as male.

Transgender Female- A person assigned male at birth who identifies as female.

Biological Male- A person assigned male at birth, with anatomical and physiological male characteristics present at birth.

Biological Female- A person assigned female at birth, with anatomical and physiological female characteristics present at birth.

Cisgender Male- A person assigned at birth as a biological female who identifies as female and with feminine gender standards.

Cisgender Female- A person assigned at birth as a biological male who identifies as male and with masculine gender standards.

Intersex- A person who, at birth, has biological characteristics of both or neither sexes, male or female. Intersex infants represent 2% of live births in the United States and are often left out of discussions of biology, sex, and gender.


Transgender females
The most common argument revolves around the eligibility of transgender females taking part in the female division of their sport. Specifically, with question in regard to the amount of testosterone within their bodies, muscle mass, bone density, general strength and power. That lead to questions over unfair advantages on their prior physiological development and training. An example of an athlete is Fallon Fox, who is the first transgender athlete to compete in MMA on the professional level.


It is statistically shown that biological males have a higher overall strength when compared to females, especially in regard to upper body strength. A common misconception is that this is because biological males have a greater incidence of Type II muscle fibers and are thus have a higher force output within the muscle tissue when compared to biological females. However, studies have shown muscle fiber distribution is genetic and environmental, that biological sex does not play any role. In addition, it has been shown that overall power output direct from the muscle tissue itself, again, is not specific to biological sex. Muscle tissue is capable of exhibiting the same level of power output between individuals with no regard to biological sex but instead is attributed based on size. As the previous study also examines, one of the main contributors to the statistical difference in strength between biological males is muscle mass.


Crap: Biological females have fewer amounts of Type II muscle fibers and are not as strong as biological males.

Fact: Muscle fiber distribution is based on genetic lineage and is not subject to biological sex. Muscle fibers are all capable of producing the same amount of force, depending on muscle fiber type. Strength differences are attributed solely based on Cross Sectional Area (CSA).


Branching off subject for a moment, a common myth is that cisgender females who lift weights will get bulky. Which is what has led to a common fear of the weight room among cisgender females at the gym, in addition to a cultural standard that femininity revolves around being weak. This is simply not true, femininity is not defined by strength (or lack thereof) nor will biological females bulk up like a balloon animal the moment they lift a dumbbell. But why is that? Well, the simple answer is hormones, but granted it’s not that simple. Testosterone is an anabolic sex hormone that is produced in all individuals which aids in the development of lean muscle tissue, bone density and sex drive. In regard to muscle tissue, Testosterone increases Muscle Protein Synthesis. Which is the body’s form of utilizing the protein we consume by breaking down the amino acids and shuttling them to repair the damaged muscle tissue. With much higher levels of MPS due to increased levels of Testosterone in the system which is produced from the testes. This is what attributes to a larger muscle mass in biological males versus females despite no difference in the distribution of muscle fibers.


Crap: Lifting weights will make biological females bulky.

Fact: Testosterone increases Muscle Protein Synthesis that helps build muscle mass. Biological females do not produce enough testosterone to build muscle mass on such high levels. Femininity isn’t defined by strength or size (or lack thereof).


So back to the question, should transgender females be eligible to compete in the female division in sports or does this lead to an unfair advantage? Since the main point of the discussion is surrounding the role of testosterone that is produced in the body. Transgender females can transition in a number of ways that limit or block testosterone production. This could include, transitional surgery that involves the removal of their male genitalia, use of androgen suppression therapy, and/or begin transition prior to the onset of puberty which does not permit the development of male characteristics in the first place.

Regardless of how a transgender female chooses to suppress or eliminate the production of testosterone in their body, it has shown that reduced testosterone levels have led to reduced strength, reduced CSA, muscle mass, and reduced power output from muscle tissue*. Several leading bodies of competitive sports have already established policies reflecting exactly this. Specifically, the International Olympic Committee and the National Collegiate Athletic Association. The policies require transgender females who wish to compete in the female division must maintain low amounts of testosterone in their system for a minimum of 1 year in order to allow these changes to take effect.

*Minimal studies are available that are reflective of transgender athletes, thus a study referencing cisgender males undergoing similar hormone therapy for treatment of prostate cancer is used. While the population is different, the effects of reduced testosterone on muscle mass, CSA, and performance are the same. The absence of data and studies done to explore physical and strength changes in transgender identifying athletes and persons shows a distinct need for conversations like this one and the impetus for studies which seek to understand how transitioning changes or impacts the bodies of athletes.


Thus physiologically, transgender females who have gone through surgery or are undergoing hormone therapy for an extended period of time, have no advantage over similarly trained athletic biological females.


Crap: Transgender females have an unfair advantage due to the previous high levels of testosterone that has built muscle mass and strength.
Fact: Once testosterone is suppressed in the body, muscular strength and power output is diminished after an appropriate period of time. Even if muscle size doesn’t fully diminish, strength and power output will.


There have been arguments regarding bone density between biological males and females. That biological females specifically have lower bone density than biological males and thus are at an increased risk of injury when taking a hard impact. This is commonly seen in combat sports such as MMA, Boxing, Tackle Football and similar sports. While biological females are more prone to develop degenerative bone disease due to a variety of cultural, psychological and biological factors. Body weight is directly correlated to bone density as well as muscular strength. Which is why weight divisions exist in certain sports. Weight training has been shown to improve bone density, especially within female athletic populations that render this argument moot.


Crap: Transgender females shouldn’t compete in a woman’s division to due perceptions of decreased bone density that will put cisgender female athletes at an increased risk of injury.

Fact: There are no increased risks of injury to due transgender participation that are not otherwise present in individual sports.


Another common argument is the fear that a person can pretend to be a transgender female in the interest of simply competing to win. Both the IOC and NCAA policies however do require that trans athletes declare their status and maintain their hormone levels for an extended period of time before they can be eligible compete, thus making this argument moot. However, as referenced in one of the first articles at the beginning of this article. There is no consistent policy on the high school level regarding transgender athletes which has fueled a lot of this discussion. Since High School athletics deals with minors, there are numerous other considerations to take into account as more consistent and educated policies are developed, however administrations should take the lead from the NCAA and IOC as they adopt their policies to be inclusive to all prospective athletes.


Crap: Men can just put on women’s clothes and compete in a female division.

Fact: The policies of the IOC and NCAA require an extended period of time from declaration as transgender to eligibility to compete. In addition, once the athlete competes in the new gender division, they aren’t eligible to return to their previous division.  Also, there is no documented cases of a male athlete willfully pretending to be female for the sake of competitive advantage.

Transgender Males

On the other side of the spectrum, the discussion continues with the eligibility of transgender males to participate in the male division of their sport. Again, with the role of testosterone coming to play here, but in this aspect with it as considered a form of doping or as a Performance Enhancing Substance. For transgender males, transition also involves the use of hormone therapy in the context of suppression hormone production of estrogen and progesterone while taking testosterone therapy. An example of a Transgender Male athlete is Chris Mosier, who is the first transgender athlete to be selected for the U.S. National Team.

All biological females produce testosterone, which is an anabolic sex hormone that aids in the development of lean muscle tissue and regulates sex drive. However, it is not produced at nearly the quantity of biological males due to the lack of male genitalia. Instead, biological females produce large amounts of estrogen and progesterone, which are sex hormones that play a significant role in the biological female reproductive system in addition to the regulation of bone density. As we learned above, testosterone plays a role in the development of lean muscle tissue and mass through the optimization of protein muscle synthesis. Thus, the more testosterone a person has, the easier it is for them to increase their Cross Sectional Area Remember, Cross Sectional Area does play a role in developing muscular strength and power output even though it is not necessarily synonymous with it. It is possible to look like a balloon animal and also have the strength of one too, but that’s a different conversation altogether.


Crap: Bulky muscles like a bodybuilder means you’re stronger.

Fact: While large muscles don’t necessarily equate to high strength. If an individual increases their muscle size from anaerobic training, that is power and strength training. They will see an increase in force output from their muscle fibers.


Part of the process of transition for Transgender Males involves the use of estrogen blockers or surgery, while taking testosterone supplements to give them more characteristics and functions of biological males. This has led to discussions and controversy over the role of these supplements as it pertains to the use of Performance Enhancing Substances and Blood Doping in sports. Is it a loophole around the current doping guidelines for transgender males to use anabolic steroids in sports? Well, not quite. The IOC and NCAA policies as well as the World Anti-Doping Agency which is the independent authority regulating doping on all levels of professional sport instated policies regulating the use of anabolic steroids specifically for transgender males. The IOC and NCAA policy states that transgender males are permitted to compete in the male division of their sport without restriction, however like all athletes. Transgender males are required to adhere to all the same guidelines in regard to the WADA policies concerning the use of anabolic steroids. The WADA policy is one based on each individual who must apply for a Therapeutic Use Exemption (TUE) and even still, the among of testosterone in each individual’s system must be consistent with that of biological male athletes.


Crap: Transgender males use of the anabolic hormone testosterone is doping and should be considered cheating.

Fact: After receiving a Therapeutic Use Exemption, transgender males are still required by the World Anti-Doping Agency to adhere to the same policy regulating acceptable levels of testosterone in the body as any biological male competing in the male division.

For both Transgender Males and Transgender Females, according to the IOC and NCAA guidelines, once the athlete has declared their status as transgender to the administrators for their sport, they are no longer eligible to compete in the other division. For example, once a transgender male competes in the male division, they are no longer eligible to compete in the female division of their sport. This policy is in place, again, to prevent cheaters from taking advantage of these inclusive policies.


Crap: Males can cheat the system by dressing in female clothing and pretending to be female to compete.

Fact: It is quite a substantial process for a transgender person to be eligible to compete in the division of their selected gender. Once they are eligible, they are not permitted to return to the previous division they competed.


Sex and Gender Verification in sport has a long, unethical and complicated history. While the current guidelines are still in the process of being accepted in the worldwide sports community, they are a step in the right direction toward building inclusion for transgender individuals to participate in all sports at any level. It will continue to take time, social, and scientific research to fully understand this issue more and to adopt more widespread and consistent policy. It is important to recognize that, again, on an anatomical and physiological level; with respect to each person as an individual. There are no substantial differences in the performance capabilities of transgender athletes and their cisgender counterparts.

Crap: “The fundamental, ineluctable fact is that a male competitor who has a sex reassignment procedure still has a genetic makeup that confers a physical and physiological advantage over women.” 

Fact: While transgender athletes still face significant barriers that make sports a harsh, intimidating and discriminatory environment. There is no fundamental biological, physical, or physiological reasons why transgender athletes cannot participate on an equal playing field with their cisgender counterparts.

Look forward to another discussion regarding Intersex athletes in an upcoming article!

By Dirk Smith