Caster Semenya's lengthy legal battle over her right to compete in certain women's track and field events in spite of naturally high testosterone levels has hit its most prominent, and perhaps final, snag. A Swiss court determined Tuesday that they will uphold the rules of track's governing body that affect female runners with differences of sex development (DSD). What this means is that Semenya will not only be barred from defending her Olympic 800-meter title at the 2021 Tokyo Games, but she also won't be allowed to compete at any top women's competitions in distances ranging from 400 meters to the mile unless she medically reduces her testosterone level.

"I am very disappointed by this ruling, but refuse to let World Athletics drug me or stop me from being who I am," Semenya said in a statement through her lawyers, per the Associated Press. "Excluding female athletes or endangering our health solely because of our natural abilities puts World Athletics on the wrong side of history."

She would be able to lower her testosterone level, according to the ruling, through taking birth control pills, having testosterone-blocking injections, or undergoing surgery. Semenya took birth control pills, which she later said made her injury prone, according to the AP, at the behest of the governing body for five years before regulations had to be suspended because of an appeal from an Indian sprinter.

The South African Olympic Champion, who has taken first in the 800m at the 2009, 2011, and 2017 World Championships -- as well as the 2012 and 2016 Olympics -- has spent her entire career competing while track and field officials claim her naturally high level of testosterone should disqualify her from events against other women. 

World Athletics, the aforementioned governing body, argued that these natural physical attributes give Semenya an unfair advantage in competition. In 2011, the governing body required female athletes to "have testosterone levels below ten nanomoles per liter, the bottom limit of the "normal male range,'" according to the New Yorker. Semenya exceeds this range. 

Tuesday's particular ruling was a dismissal of an appeal against a May 2019 verdict from a Court of Arbitration for Sport ruling which determined that discrimination against Semenya was "necessary, reasonable and proportionate" for maintaining fairness in women's track. That ruling was briefly overturned in July 2019, which allowed her to compete in an 800 meter event in Palo Alto, California without taking testosterone-suppressing drugs. She won that event.

But that overturned ruling was later reversed. The court ruled Tuesday that the May 2019 verdict did not violate "fundamental and widely recognized principles of public order," nor did it compromise Semenya's "guarantee of human dignity."

As for the world champion's future, it appears she is preparing to compete in the 200 meter event, indicating she expected to lose this case. The banning does not prevent her from competing in shorter races, but she hasn't been anywhere near as successful in those events than the ones she won medals in.