Vital Signs

Should a woman’s testosterone level matter in sports?

Editor’s Note: Vital Signs is a monthly program bringing viewers health stories from around the world.

Story highlights

International Association of Athletics Federation restricted women with high levels of testosterone

In 2015, Indian 100-meter runner Dutee Chand challenged the regulation and won

Chand and fellow hyperandrogenous athlete Caster Semenya will compete in Rio

CNN  — 

Sports are not a level playing field. They never will be.

Picture the lineup of athletes along a start line as they wait eagerly for the sound of the gun or gymnasts as they perform flips on a balance beam with unfathomable precision.

Although tremendous skill, hard work and thousands of hours of practice are involved in them molding their bodies for sporting excellence, nature is what brought these athletes to the front line.

Each competitor will vary in a multitude of ways, including height, weight, age and proportion. There are also differences in less-visible characteristics such as lung capacity, recovery rates and even hormone levels, with this variability generally accepted as a standard part of sporting culture.

But that hasn’t always been the case when it comes to the hormone testosterone.

Differences in testosterone, specifically higher levels of testosterone among female athletes, have been a topic of debate in the Olympics for many decades, with officials stating concerns that it could provide an unfair advantage.

But given the sea of attributes giving each individual an edge, should levels of testosterone matter?

The right to run

Until recently, women with naturally high levels of testosterone – known as hyperandrogenism – were not allowed to race without undergoing medical interventions to lower their levels of the hormones if they were measured to be within the range typically associated with men. This was a prerequisite as part of the International Association of Athletics Federations’ Hyperandrogenism Regulation, which required athletes to prove that they derive no advantage from their relatively high testosterone levels, or else not compete.

The regulations were introduced in 2011 after an 18-month review by an association expert working group in conjunction with the International Olympic Committee and were “based on strong scientific consensus that the clear sex difference in sports performance is mainly due to the marked difference in male and female testosterone levels,” according to a statement. They were stated to have the aim to “preserve fair competition.”

But in 2015, things changed.

That year, India’s fastest woman, Dutee Chand, challenged the association, arguing that she had a right to run and compete without artificially changing her body’s hormones.

The Court of Arbitration for Sport ruled in the 100-meter sprinter’s favor, arguing that the association had not proved that testosterone gives athletes an unfair advantage.

The court then gave the International Association of Athletics Federations two more years to find evidence of the degree of performance advantage provided by increased levels of the hormone, which the association is now addressing.

Until then, the regulations would be suspended.

Competing without drugs

For 20-year-old Chand, the ruling meant she could compete on the world stage at the Rio Olympics and live her dream of representing her country in the 100 meters.

The decision also meant that South African runner Caster Semenya – a fellow athlete with naturally high levels of testosterone – was able to compete without being forced to take testosterone-suppressing drugs. She would also escape further invasive screenings.

In 2009, when Semenya was 18, she won gold in the women’s 800 meters at the 2009 World Athletics Championship in Berlin. Her victory was quickly marred by widespread scrutiny of her sex, with the International Association of Athletics Federations launching an investigation hours after the race finished. Her sex and testosterone levels were tested, and although she was allowed to keep her gold medal, the association ultimately enforced the Hyperandrogenism Regulation in 2011.

Some athletes have compared racing against Semenya to “running against a man.”

What is hyperandrogenism?

Although commonly associated with men, testosterone is also produced naturally by women, but to a lesser extent. The hormone helps regulate the menstrual cycle and plays a role in the development of muscle tissue. As with anything in nature, some women have slightly higher levels than others; this is known as hyperandrogenism.

The condition is estimated to occur in 5% to 10% of women.

The most common symptoms of hyperandrogenism include excess hair growth, acne, alopecia and irregular menstrual cycles, which often appear gradually over a period of years.

The majority of women with the condition have a syndrome called polycystic ovary syndrome, according to David Ehrmann, professor of medicine at the University of Chicago. The syndrome can cause ovaries to have large, underdeveloped follicles that may be unable to release eggs and ovulate.

“It’s one of the most common hormonal disorders in women. Normally, it starts around the time of puberty, but it can manifest in the late teens and early 20s as well,” Ehrmann said.

When a woman has polycystic ovary syndrome or hyperandrogenism, her body is less able to regulate levels of testosterone produced in the ovaries.

“Their testosterone levels are usually two to three times the normal limit of an average woman,” Ehrmann said. But they can go higher, which is when the regulations kick in.

Defining sex

To add to the ambiguity of defining sex, there are many chromosomal variations beyond the typical XY and XX. According to the World Health Organization, one in 400 people has chromosomes that differ from the standard XY or XX formation.

During the 1964 Olympics, Polish runner Ewa Klobukowska helped set a world record in the 4x100 meter relay. However, her efforts were discounted in 1967 after the International Association of Athletics Federations found her to have “one chromosome too many.” Klobukowska was found to have an extra Y chromosome – in addition to the traditional XX female chromosomes – during a sex test.

For many years athletes, women’s rights advocates and geneticists criticized the sex tests conducted by the association, as they ensured that only women with XX chromosomes were allowed to compete, rather than account for natural variation.

Their battle was won in 1992, when the International Association of Athletics Federations abandoned all forms of systematic sex testing.

The pressure to be feminine