RE: Too much talk about equipment & not enough talk about fitness & nutrition.
Good question. Last summer I carried 50 lbs of lead shot in a camelbak five nights a week up and down trails with the dog. Three miles on work nights and six miles on days off. Lost 15 lbs and lost 5 more on an August pack trip with scouts. Nobody could out-walk me up hills last year (except the elk, of course). Kept it off for hunting season, then look out! It's them coworkers donuts, I tell ya! Just started on the camelbak again last week with 60 lbs.
Looking forward to more answers to this one.