8.4 Emergency Approach March Load Circumstances could require Soldiers to carry loads heavier than 72 pounds such as approach marches through terrain impassable to vehicles or where ground/air transportation resources are not available. Therefore, larger rucksacks must be carried. These Emergency Approach March Loads can be carried easily by well-conditioned Soldiers. When the mission demands that Soldiers be employed as porters, loads of up to 120 pounds can be carried for several days over distances of 20 km a day. Although loads of up to 150 pounds are feasible, the Soldier could become fatigued or even injured. If possible, contact with the enemy should be avoided since march speeds will be slow.
I carried 65 to 90 pounds in Vietnam (No, I did not see John Kerry while there), the lighter load while patrolling in the mountains. Walking is OK, but if you have to run with it, it’s a kicker! Especially through rice paddies!
Later in training in the mountains in Korean my team had packs weighing 105 to 115 lbs. I would not want to carry much more AND fight. Of course, we always dropped the bulk of the load before an assault.
I was 5’ 8” and 155 lbs at the time.