Like many military members, David Léasure was devoted to his fitness routine. When he joined the Navy straight from high school in 2011, the first thing he did with his paycheck was to join an online exercise program. He adhered to the meal plans, took all the supplements he was supposed to, and generally saw the results he wanted through hours at the gym. What Is It That Crumbles Away and Makes Us Give Up? Despite being physically bigger and generally healthier, he began to wonder why he was...