[Houshalter]

Right but it's evidence towards the hypothesis "standing for three hours will increase your life span". It seems less likely that people who live longer are inherently more likely to stand.

But yes I see your point. A lot of pop science "doing X will help you live longer" strikes me as complete bullshit.

[kybernetikos]

You're quite right of course (although actually, it seems very plausible to me that fit people are more likely to stand more / choose jobs where they will stand more) My comment was mainly out of the frustration I have because so many interventions are very difficult to do and so I want good confidence that they will actually make a difference, but most research just gives you at best strong correlations.

Still, I've got a standing desk now...