Now a large study undertaken by the University of Exeter and University College London and published in the International Journal of Epidemiology suggests that the problem isn't sitting, it's not getting enough exercise, and that standing (which may be more comfortable for some people in any event) doesn't help — though treadmill desks and bike desks would presumably make some kind of difference.
Conclusions: Sitting time was not associated with all-cause mortality risk. The results of this study suggest that policy makers and clinicians should be cautious about placing emphasis on sitting behaviour as a risk factor for mortality that is distinct from the effect of physical activity.
…"Our study overturns current thinking on the health risks of sitting and indicates that the problem lies in the absence of movement rather than the time spent sitting itself," study author Melvyn Hillsdon of the University of Exeter said in a statement. "Any stationary posture where energy expenditure is low may be detrimental to health, be it sitting or standing."
Sitting for long periods doesn't make death more imminent, study suggests
[Elahe Izadi/Washington Post]
Associations of sitting behaviours with all-cause mortality over a 16-year follow-up: the Whitehall II study
[Richard M. Pulsford, Emmanuel Stamatakis, Annie R. Britton, Eric J. Brunner4 and Melvyn Hillsdon/International Journal of Epidemiology]