[Someone]

I think varicose veins are evidence that standing up all day isn't what we were evolved for.

Looking at chimps, gorillas, orang utan seems to conform that. In my limited knowledge, those species spend hours sitting or lying down.

=> I would guess it is not the sitting, but the sitting for long stretches in the same posture that is the problem.

[oconnor0]

Interesting. What research is there on people standing all day getting varicose veins and the negatives of that versus sitting all day and the negatives of that?

[cormullion]

Plenty of anti-standing information here:

http://www.hazards.org/standing/index.htm