To add a personal anecdote, I once walked 25 miles in about 8-9 hours* with a heavy bag, and then showered & walked to work afterwards. I was kind of out of it,

To add a personal anecdote, I once walked 25 miles in about 8-9 hours* with a heavy bag, and then showered & walked to work afterwards. I was kind of out of it, but definitely not falling-down-tired or anything like that. *I severely misjudged the length of the trip before setting out, thought it was about 5-6 miles.