If you spend all day sitting in front of the computer at work, only to go home and sit on a sofa for a few more hours, it's time to reassess your lifestyle.
People should aim to be on their feet for four hours of the working day, Public Health England has said - in order to minimise the chance of obesity and premature death.
Yet in the UK, most people spend a lot more time being sedentary than is recommended.
"For those working in offices, 65-75 per cent of their working hours are spent sitting, of which more than 50 per cent of this is accumulated in prolonged periods of sustained sitting," the researchers say.
They urged employers to introduce "sit-stand desks" - only one per cent of offices currently have them. This compares to 90 per cent of offices in Scandinavia.
Think it's a bit much? Never fear: to get you started, the organisation recommends two hours as an initial target, followed by the full four hours at a later date. The study is published in the British Journal of Sports Medicine.
"The evidence is clearly emerging that a first 'behavioural' step could be simply to get people standing and moving more frequently as part of their working day," they say, adding that this is likely to be more achievable than targeted exercise.
On top of sit-stand desks, they suggest more regular walkabouts and avoiding prolonged static standing, which can end up being just as harmful as sitting.