This one looks like they at least asked about sitting specifically, which is better than most ("watching television" is a standard survey question, so often it

This one looks like they at least asked about sitting specifically, which is better than most ("watching television" is a standard survey question, so often it is just assumed that "watching television" == sitting and look for correlations from there). There are a few limited studies that do direct experimental manipulation of sitting without breaks vs. sitting occasionally interrupted and suggest that further study might be useful. I would be surprised (but maybe not too suprised) if there weren't more detailed longer term studies in progress involving hardware monitoring devices and other clever setups that could make more detailed correlations that could be useful. So far, studies are just saying "here is some evidence that activity level does not have an extremely simplistic correlation with health." Puting it like that, it doesn't seem that surprising (or useful).