I Train by hiking/walking everyday for an hour flatland with my exo k2 5500 with water bag in it that equals 70lbs total weight.
If i was hiking to hike and not training, hell no, I going to use a pack more suited for the task. Normally something smaller and lighter weight. But that all depends on the trip Length and season. Its fair to say internal frame or frameless hiking packs normally limit out at 35ish pounds. Framed hunting packs work 40ish lbs up depending on the pack