South African runner Caster Semenya handled Wednesday's court ruling the best she could: By posting a helpless emoji and hardly reacting at all.

The two-time Olympic gold medalist in the 800 meters will be forced to follow a similar blueprint as she traverses her running career with a human rights saga attached to it.

The Court of Arbitration for Sport's panel of three judges denied Semenya's appeal against IAAF rules that will force female runners like herself to decrease naturally high testosterone levels in select track and field events as intersex athletes.

USA TODAY Sports unpacks the controversial ruling and why it matters for intersex athletes and the future of the Olympics, including the 2020 Tokyo Games.

Why is the ruling controversial?

The court noted Wednesday that these rules, created by the International Association of Athletics Federations (IAAF) and based on scientific evidence, are indeed discriminatory but would be applied nonetheless. "Such discrimination is necessary" to preserve "the integrity of female athletics," the judges determined.

The rules were reversed from where they stood in the 2016 Rio Games when the same court suspended any limitations to an athlete's testosterone use — citing discrimination. At the time, intersex studies expert Joanna Harper told USA TODAY Sports, "this is a huge human rights victory, but sports not so much."

Now it's considered the opposite, with South Africa sports minister Tokozile Xasa saying the regulations "trample on the human rights and dignity of Semenya and other athletes."

What is an intersex athlete?

These are athletes who identify as having "differences of sex development." Intersex is an umbrella term for people who are born with sex characteristics “that do not fit typical binary notions of male or female bodies,” according to a definition by the human rights arm of the United Nations.

Who is Semenya?

Semenya is hyperandrogenous, meaning her body naturally produces high amounts of testosterone, the hormone that helps build muscle, endurance and speed. Experts believe Semenya and other intersex athletes, although born female, develop internal testes around the time they hit puberty — keeping their gender the same but creating an unfair advantage.

What is the difference between intersex and transgender?

Typically, but not always, an intersex female athlete will present with manly features while identifying as female and showing so on their birth certificate. Transgender athletes were born one gender but identify as a different gender and transition to the opposite sex to address their gender dysphoria, a condition that causes strain on an individual's mental health.

Why is Semenya headlining the controversial ruling?

Semenya's supposed unfair advantage was on display in the 2016 Olympic Games when she won the 800 meters in world-record form. But when she's had to limit her testosterone levels her times have dipped significantly and evened the playing field.

But the rules, while supported by scientific evidence, single Semenya out since the three judges only wanted the IAAF to apply the rules up to the 800 meters because an advantage was unclear in the 1,500-meter and longer distances.

How does this affect the future of the Olympics?

Semenya will undoubtedly be affected for her pursuit of a gold medal at the Tokyo Games because the International Olympic Committee (IOC) adopts the IAAF's rules. But the ruling was not just about Semenya. It addresses the similarities between intersex women and transgender women who have transitioned from men.

At the 2016 Rio Games, had a transgender female runner competed, there was no testosterone limitation in place — meaning an individual born male could've had an unfair advantage similar to Semenya. While almost all female runners deliberately block their testosterone levels as part of their transition, the rules now avoid an even bigger battle over fairness.

What will Semenya do now?

When Semenya has had restrictions on her testosterone in the past, she's remained elite but proved to be far off her usual dominant self. Semenya, who was a bronze medalist in the 1,500 meters at the 2017 world championship, could change her event if she doesn't want to limit her testosterone at all. The court noted Wednesday that the rules could change again based on more data presented, however, that likely won't come in time for Semenya's Olympic pursuits.