If there's one thing science has been trying to get through to us over the past 12 months, it's that sitting down for long periods of time is very, very bad for you. Studies have shown that it increases your risk of type 2 diabetes and cardiovascular disease, it leads to weight gain and back pain, and it affects super-fit people and couch potatoes pretty much alike.
All of which sucks, because the majority of us have no choice but to sit for 8 hours a day as part of our jobs. But a new study by UK researchers offers a different perspective, saying that prolonged sitting doesn't appear to be killing you any faster than standing (bad luck, anyone who forked out for a standing desk).
"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," said one of the researchers, Melvyn Hillsdon from the University of Exeter. "Any stationary posture where energy expenditure is low may be detrimental to health, be it sitting or standing."
Hillsdon and his colleagues tracked the health of 5,132 people (3,720 men and 1,412 women) over 16 years to see how their sitting, standing, and exercise habits affected their their overall mortality risk. They took into account their total sitting time and categorised this as work or leisure time, with leisure time split into watching television and not watching television.
Total standing time, walking, and other forms of physical activity were also taken into account.
Publishing in the International Journal of Epidemiology this week, the researchers report that after controlling for a number of factors, including smoking status, alcohol consumption, diet quality, and body mass index (BMI), they found no link between their participants' overall mortality risk and how long they sat, whether at work or during leisure time.
"Across almost 16 years of follow-up, no prospective associations were observed between five different indicators of sitting time and mortality from all causes," they conclude.
But before you start wheeling your chair over to your work colleague so you can give them a sitting down high five, you might want to think about your daily activity levels first. The researchers note that the majority of their participants were office workers in London - a city that requires a lot of walking to and standing on public transport if you want to get anywhere.
A possible explanation for why their results contradict research-backed advice from the UK National Health Service (NHS) that "remaining seated for too long is bad for your health, regardless of how much exercise you do" is that the average daily walking time for their participants was over double the reported UK average.
"A number of prospective cohort studies have demonstrated that both habitual active transport and daily walking are inversely associated with risk for mortality," they write, citing another study that found that for healthy participants, sitting was only associated with mortality risk in those who reported zero minutes of weekly walking or moderate to vigorous physical activity.
"It is therefore possible that the higher than average energy expenditure in the current study may offer a degree of protection from any deleterious effects of high volumes of sitting," they hypothesise.
Rather than using the results to tell us that we're free to sit for long periods of time with careless abandon, the researchers recommend that policy makers and healthcare professionals hop off the standing desk band wagon and instead focus their efforts on recommending increases in physical activity instead. "[They] should be cautious about placing emphasis on sitting behaviour as a risk factor for mortality that is distinct from the effect of physical activity," the study concludes.
So it's actually pretty simple. Don't beat yourself up about how you have to spend 8 hours a day or more glued to your desk, and don't rush out and buy a standing desk if you'd really just prefer to sit. Instead, make the commitment to walk more every day to keep your energy expenditure levels up. Because one thing's for sure - it'll be a whole lot better for you than sitting around stressing about what you can't change.