I've just been reading this article on why sitting still is bad for you and, if I read it right, standing still is not much better . It is hardly news. We were designed to be active. But it is always uncomfortable to have the abstract awareness of harm condensed to actual damage vectors. I've tried for years to get going the Pomodoro principle - but my concentration span doesn't seem to like the short 25 minute periodicity. Time to make more effort perhaps.