Seven miles into the 2004 Cherry Blossom Ten Miler in Washington, D.C., a few months before that summer’s Olympic track trials, I felt a strange pop in my lower back. Hobbling gingerly to a halt, I realized that my race was over. As it turned out, so was my track career. I’d suffered a stress fracture in my sacrum, the bone that connects your lower back to your pelvis. It’s an unusual injury, and in the months that followed, I puzzled over my fate. Had I been wearing the wrong shoes, or logging too many miles, or not stretching enough? It wasn’t until a decade later that I began to consider another possibility: perhaps I hadn’t been eating enough.
In 2014, the International Olympic Committee unveiled something it called “relative energy deficiency in sport,” or REDs. The link between eating disorders, missed periods, and weakened bones was already widely known as the “female athlete triad.” But REDs adopted a broader view. Failing to get enough calories to fuel both normal metabolism and the rigors of training were associated with a wide range of problems in 14 categories: not just poor…
