Having looked at this article, I think they have got wrong( we have some adjustable desks in our offices). It is not a question of standing v sitting but of employees staying in one place against those that can move about. In most offices there is an expectation that an employee can be found in one place and bosses do like the idea of them wandering off, so the modern office is designed to tie you to one spot ie the PC. In older offices staff spent a considerable amount of time moving around filing, photocopying etc. This mean that they gave themselves a bit of a gentle all over work-out. The current trend seems to give them everything at their desks and in most places they are even encouraged to take lunch at their desks.