Study: Which service branch requires the toughest basic training?

The data are contained in a new military report that traces stress fractures from 2004 to 2010 for both recruits and troops already in the force. Across all the services, recruits suffered such fractures 18 times as much as non-recruits. The reasons aren’t surprising: many young Americans don’t exercise much, and the rigors of boot camp — long marches, jumping jacks, runs — sprain a lot of ankles and break a lot of bones. But a deeper dive into the numbers shows a marked difference in bone-crunching rates among the five services’ recruiting bases.

The Marines’ San Diego training station is the toughest in the nation: 688 recruits broke lower-leg — tibia and fibula — bones there from 2004 to 2010 (that translates into a rate of 28.9 fractures per 1,000 years of training). Ranked No. 2 on the list is the Marines’ Parris Island base, with 613 breaks and a 24.1 rate. The Navy’s lone Great Lakes boot camp near Chicago had 604 fractures (16.0 rate) to claim the third spot. The Air Force, Army and Coast Guard brought up the rear.