These young athletes were bound for stardom until a mysterious condition derailed their running careers

They were two exceptionally promising athletes, seemingly bound for trackn and field stardom, when their careers were derailed by a condition that doctors and researchers say they are only now beginning to understand.

Their experiences highlight the damaging expectations that can surround athletes, blurring the thin line between the discipline that allows athletes to achieve superhuman feats and the disordered patterns of behavior that can harm their health, as they push themselves, and are pushed by their coaches and trainers.  

Mary Cain was the youngest ever US track and field athlete to make the World Championships team, a teenage phenomenon who held several national age-group records in middle-distance running.