EXPLAINER: What exactly are track's testosterone rules?

TOKYO (AP) — The complex testosterone regulations in track and field have become an issue again at the Olympics after Namibian teenager Christine Mboma won a silver medal in the 200 meters after being banned from some other events because of her natural hormone levels.

Mboma was one of two 18-year-old Namibians to surprisingly qualify for Tuesday’s 200 final. Her teammate, Beatrice Masilingi, is also affected by the testosterone rules. But their bans only apply to races between 400 meters and one mile, allowing them to run in the 200 at the Olympics.

Both Namibian teenagers were barely-known in international track and field until this year, when they started running some extraordinarily fast times. That prompted governing body World Athletics to order tests on them in the weeks before the Olympics. They were found to have natural testosterone levels that are higher than a limit set by the sport for female athletes.

They are the same rules that have sidelined two-time Olympic 800-meter champion Caster Semenya.

SO WHAT ARE THE TESTOSTERONE RULES?

Essentially, the rules are designed to deal with the dilemma presented by female athletes who were born with conditions that mean their natural testosterone levels are much higher than the typical female range. World Athletics says that’s a problem because the high testosterone gives them unfair athletic advantages over female athletes with more typical testosterone levels.

The answer, according to the current rules, is to ban the athletes from certain events unless they agree to artificially lower their testosterone to a level set by World Athletics.

That’s caused controversy for many reasons, but the most emotive appears to be this: Track authorities are basically asking the athletes to artificially manipulate their natural...