Would you rather spend 40 hours a week standing in one spot or sitting down?

Neither. While my job primarily was desk bound--and stand-up desks were just beginning to come into fashion when I retired--most of the work was on the phone, so I spent a lot of time standing, moving about as much as the cord allowed. (Yes, phones came with a cord in those days). As well as walkiing about to interact with the rest of staff on various issues. But then I seldom worked just 40 hours a week as well.