Fitness trackers can be addictive—and dangerous

Katherine Schreiber and Leslie Sim are experts on exercise addiction who believe that tech advances encourage obsessive goal monitoring. Schreiber and Sim loathe wearable tech. “It's the worst,” Schreiber says. “The dumbest thing in the world,” says Sim. Schreiber has written extensively about exercise addiction, and Sim is a clinical child adolescent psychologist at the Mayo Clinic. Many of Sim's adolescent patients have twin exercise and eating disorders, which tend to