Embedded, NPR's original documentary podcast, unearths the stories behind the headlines. Police shootings. Towns ravaged by opioids. The roots of our modern immigration crisis. We explore what's been sealed off, undisclosed, or never brought to light. We return with a deeply-reported portrait of why these stories, and the people behind them, matter.

Who gets to compete? Since the beginning of women's sports, there has been a struggle over who qualifies for the women's category. Tested follows the unfolding story of elite female runners who have been told they can no longer race in the women's category, unless they change their biology. As the Olympics approach, they face hard choices: take drugs to lower their natural testosterone levels, give up their sport entirely, or fight. To understand how we got here, we trace the surprising, 100-year history of sex testing.

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