With Caster Semenya back at World Athletics Championships, so is sport's thorniest problem

Champion runner Caster Semenya heads into this year's world championships with virtually no chance to win.

On Wednesday in Eugene, Ore., the 31-year-old, three-time world champion at 800 metres will run instead in the 5,000-metre race. She is not considered a serious medal contender. It's the first time since she started dominating her favourite distance well over a decade ago that anybody has said that.

The South African chose to run in a race she doesn't really want to be in, and one she's not so good at, because she has declined to submit to rules in track and field that demand she take hormone-reducing treatments if she wants to enter the 800.

Semenya was assigned female at birth, was raised as a girl and identifies as a woman. She has an intersex condition called 46,XY differences in sex development that causes male and female traits and a testosterone level higher than the typical female range. She was banned from her best event after losing her appeal of a World Athletics regulation that made women with her condition ineligible for some races.

She is not transgender. Still, her case, and those involving others who have similar intersex conditions, carries strong implications for how transgender athletes are treated and classified.

Semenya's situation, and the similar plight of 200-metre Olympic silver medallist Christine Mboma, are the most relevant illustrations of how complex track's rules are regarding the participation of women who have high natural testosterone and what some say is an unfair athletic advantage over other women.

Mboma is injured this summer and did not travel to Eugene. Semenya wasn't expected to come either, but out of nowhere, her name showed up on the start list for the longer race.

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