Show up for a few free early-morning, boot-camp-style workouts with F3, and you will find yourself more fit, with more friends, and, the founders hope, a renewed sense of purpose. You will also be given a nickname. That name will be, at best, neutral and probably not flattering, but no matter how much you might not like it, don’t complain—because if you do, the replacement will be far, far, far worse. (Note: The workouts are limited to men.)