I have always heard that it is hard walking. and a lot of it.
One has to be careful about applying generalities to specifics; otherwise doors can be closed where possibilites may actually lay.
Yes,
usually elk hunting involves lots of walking on generally uneven and often rocky terrain; however, not all elk hunts are done in this fashion. With the use of horses, large distances can be covered without a lot of walking; one does need to be able to ride however.
Elk hunting, about like anything else, can be done either by "going after them" (lots of shoe leather) or "hanging tight" in the right place (sniper nest style).