As i said possible, squaddies do it, quite regularly, but they have a rest inbetween, and take transport to save energy. I know about the 10lb tents etc, but precicely how far did you carry them ?

If squaddies are in the desert for 20 days there kit includes 10 gallons of water, ammo weapons food kit fuel etc far exeeding 80lbs, but thats for a static camp. Carried in in stages like the miners mentioned earlier

And this is from people who are used to carrying weight. Be warned ! A knee injury when you cant apply weight is painful.