To celebrate the Air Force's birthday (18 Sep 1947), the cadets ruck up and down the ramps at the "Swamp." In their backpacks, they carry canned goods that are donated to a local foodbank at the completion of the ruck. The length of the ruck increases each year to correspond with the Air Force's age--is year is the 75th birthday, so the cadets rucked 7.5k.