Do adaptations to stress exposure show up as changes in blood chemistry or heart function? The answer appears to be “yes”. In his Newsweek article “Lessons in Survival”, Ben Sherwood reported on a very interesting study of elite Army Airborne and Special Forces soldiers that probed the differences between those who could and could not endure an extremely stressful 19-day mock-prisoner-of-war camp. The Resistance Training Laboratory, located at a secret location near Fort Bragg, North Carolina, subjected participants to sleep deprivation, blaring music, semi-starvation and — worst of all — intense interrogation techniques used by enemy forces during WWII, Korea and Vietnam. “The goal is to simulate hell on earth like the Hanoi Hilton in Vietnam or Al Qaeda’s torture chambers,” according to Sherwood. In another test of mettle, at the Navy Diving and Salvage Training Center in Florida, trainee divers were put through stressful routines such as being thrown into a pool with their hands and feet bound, and underwater ocean swimming from 3 miles offshore to a target on shore.