Sitting for long periods is not bad for you, say researchers - as long as you stay active the rest of the time.
The study, which contradicts the UK's NHS advice, found those who spent hours sitting at work or home did not have an increased risk of dying.
The findings challenge previous research suggesting the act of sitting itself causes harm.
NHS advice states that remaining seated for too long is bad for health regardless of how much exercise a person does before or afterwards.
But a team from the University of Exeter and University College London believe the real problem is lack of exercise. Dr Melvyn Hillsdon, of Exeter, said: "Our study... indicates that the problem lies in the absence of movement rather than the time spent sitting itself. Any stationary posture where energy expenditure is low may be detrimental to health, be it sitting or standing."