Being physically in shape is important, but I believe being mentally prepared for the hunt is equally so, if not more.
I've seen lots of people in seemingly good shape turn around and go back to the pickup, because they didn't want an elk badly enough: though they thought that they did beforehand.
I've also seen a fair number of bigger guys make it to the elk, because they wanted to, badly enough. Throw in the nasty weather, altitude sickness and whatever else....and you'll find out if you want an elk bad enough.
