Long ago 1966/67 we carried a 30 pound or more sandbag in our ruck sack along with our equipment load and water ran 7 miles climbed a rope ladder repelled off a tower then ran the 7 miles back. Never want to do that again. Maybe we were pioneers of the vest idea.
I hear ya!
I was in the British Army - the hot deal was that we actually got paid to do all that crap!