Former president Donald Trump sat down for a wide-ranging interview on X with Elon Musk. Vice Presidential candidate Tim Walz will hold his first solo rally in LA speaking with union workers, and Mexico's most notorious drug lord released a public letter that raises questions about government collusion and corruption. Want more comprehensive analysis of the most important news of the day, plus a little fun? Subscribe to the Up First newsletter. Today's episode of Up First was edited by Julia Redpath, Pallavi Gogoi, Miguel Macias, Janaya Williams, and HJ Mai. It was produced by Ziad Buchh, Nia Dumas and Lilly Quiroz. We get engineering support from Arthur Laurent. And our technical director is Zac Coleman. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy

Who gets to compete? Since the beginning of women's sports, there has been a struggle over who qualifies for the women's category. A Martinez speaks with Rose Eveleth, the host of a new podcast series called Tested from NPR's Embedded and CBC in Canada, which traces the surprising, 100-year history of sex testing in elite sports. The series follows the unfolding story of elite female runners who have been told they can no longer race as women, because of their biology. They face hard choices: take drugs to lower their natural testosterone levels, give up their sport entirely, or fight. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy