that most people spend a lot of time sitting down

Just got back from camping, feel recently experienced with primitive living. I feel like it was probably a waste for men to do a lot of the work because our effort is generally a lot more expensive metabolically. Thus the division between man work, the hard and dangerous stuff, and woman work - the rest of it that can be done at a cheaper calorie cost and with lower quality food since they don't need as much animal protein.

I doubt ancient man was more active than he had to be, if for no other reason than the logistics of obtaining sufficient nutrition back then.

soft beds

Really missed my soft bed too.