Becoming a more effective leader often requires changing behavior. But although most companies recognize that this also means adjusting underlying mind-sets, too often these organizations are reluctant to address the root causes of why leaders act the way they do. Doing so can be uncomfortable for participants, program trainers, mentors, and bosses—but if there isn’t a significant degree of discomfort, the chances are that the behavior won’t change. Just as a coach would view an athlete’s muscle pain as a proper response to training, leaders who are stretching themselves should also feel some discomfort as they struggle to reach new levels of leadership performance.