USMC Leadership - Endurance Endurance: In the military, and particularly at MarineCorps PLDC camp - you must be in the utmost physical fitness, the demands on the body from calisthenics with LOGS, Pack Marches, Gear Runs, Obstacle courses and fitness tests are grueling. A chubby office desk muffin - isn't making it here. But further, you have to have the core strength in mind - because that will fail before the body does. If you possess and harness this strength, you can accomplish amazing things; and do them again back to back. It is not the miles that wear you down, but your attitude towards them. Suck it up, Drive on.