I made it to age 40 without a concrete plan on how to stay fit and I am a doctor. Like most American men, I had chosen a fat, sedentary lifestyle, one that universally rewards males with bellies, boobs, diabetes and erectile dysfunction. Residency and fellowship had taken their toll. With weight ballooning and fitness plummeting, I was headed down this path. Then the world turned. In February 2004, I received a call from the Army. The message was simple: Once I finished fellowship in September, I would be headed to Iraq as a field surgeon. Professionally, I was prepared. Physically, I was a...