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 as women, because of 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. Tested is a new 6-part series from NPR's Embedded and CBC. Hosted by journalist Rose Eveleth, it launches July 15, ahead of the 2024 Olympic Games. Embedded+ supporters enjoy early and ad-free access.