Well, the only running we did with our alice packs was from the squad bay to the parade deck (and vice versa) or from the classroom to formation (and vice versa). We didn't usually have much in our packs when we did this (a poncho, our "blue monster" warrior knowledge binder.... nothing too heavy).
Humps were another story though. We always carried extra cammies, ponchos, poncho liners, MREs, etc. You wouldn't expect it to be heavy, but it probably did weigh 40 lbs or so (just a guess). As long as you are in the front of the platoon (the shorter females) or the rest of the platoon keeps up, you don't usually have to run during humps. I was the tallest girl in my platoon and therefore in the back of the pack. There were definitely times I had to at least jog in order to close the gaps and stay with the rest of the platoon because the females in front of me fell behind.
If you are talking about some of the PT events i.e. the endurance course, you will run with your web belt, which holds your canteens, and your rifle but no alice pack.
I'll get back to you on the sock method.
