The day before ultrarunner and obstacle course racing superstar Amelia Boone hit “publish” on the blog post that echoed through the endurance-sports world and beyond last week, she almost didn’t go through with it. “I was like, why am I doing this? I’m not recovered,” she told Runner’s World afterward. Even after her message went live, she spent some time second-guessing her motivations. But ultimately, Boone said, the predominant emotion she felt now that her 20-year experience with anorexia has become public knowledge is relief. “It’s honestly like having a hundred-pound weight vest lifted off,” she said. Now, she no...