In many minds, military service is linked with exercise, and being in great shape. The movies show us people in uniform running, carrying heavy equipment and doing endless push-ups. Boot camp is known for drills, running and obstacle courses. Military service requires a level of physical fitness that most young people in America do not have. Less than ten percent of American teenagers get the recommended amount of physical activity each day, and nearly one in five children are obese. This has military leaders worried.