No, sitting for over 11 hours a day doesn’t mean 50% chance you’ll die in 3 years

A businessman sitting at his desk. Scientists say more research on the effect of sitting time on the length of our lives. [File, Standard]

Did you know? If you sit more than 11 hours a day, there’s a 50 per cent chance you’ll die within the next 3 years,” reads a meme posted on Facebook.

The post doesn’t give more details on if this is uninterrupted sitting or the total of the time spent sitting in a day.

Other internet sites have also linked prolonged sitting to premature death, with one publication giving the risk as a lower 40 per cent for the same 11 hours.  

But do we drastically shorten our lives by sitting for long periods of time? 

2012 study linked to the 11 hours sitting time claim

There’s little available information about the ‘Medical Talk’ Facebook page that posted the claim. We also did not trace any research that pointed to a 50 per cent chance of dying within the next three years due to a high sitting time. 

However, a 2012 study on the link between sitting time and mortality and published in peer reviewed journal JAMA internal medicine carries the same figure of 11 hours.

The study of 222,497 Australian adults 45 and older concluded that the risk of death increases when a person sits for long. This was after factoring in for variables such as sex, age, education, physical activity, body mass index and disability.

The study was widely reported at the time by international publishers such as Forbes and the UK Guardian. Both reported that the research had found that those who sat for 11 or more hours a day had a 40 per cent increased risk of dying over the next three years, compared with those who sat for only four hours a day.

We then asked experts if the 50 per cent claim was valid.  

Statistic is ‘a bogus claim’

Jeff Vallance is a professor at the Faculty of Health Disciplines at Athabasca University, a Canadian university specialising in online education. He has done wide research on health outcomes related to sitting behavior and physical activity. 

He told Africa Check that from “the scientific evidence we have, all we know is that compared to people that sit the least, people who sit the most (over 9 or 10 hrs per day) have an approximately 20 per cent increased risk of premature mortality”.

Another academic, Emmanuel Stamatakis, told Africa Check that the 50 per cent statistic is “a bogus claim”.  

“This statistic is nonsense, far from what the whole body evidence of research shows.” 

Stamatakis is a professor of physical activity, lifestyle, and population health at the University of Sydney’s medicine and health faculty. His research covers  health behaviour – such as sitting – and its influence on heart, lung, metabolic and mental diseases, and the risk of death. 

‘No study shows this’

“Sitting is a health risk in physically inactive populations,” Stamatakis said. But, he said, “even meeting the lower moderate to vigorous physical activity guidelines threshold effectively eliminates the risk”. 

“There is no study showing that there is a 50 per cent death chance to die in the next x years,” he said.

Stamatakis said no scientist had calculated the risk of death for “any risk factor”. These risk factors could include smoking, high blood pressure, physical activity, sitting and “anything else”, he said.

Exercise helps – a lot

Ulf Ekelund, a professor of sports medicine at the Norwegian School of Sport Sciences, is the lead author of multiple articles on the role of physical activity in reducing the risk for premature mortality. 

A 2016 study by Ekelund and his colleagues found that “high levels of moderate intensity physical activity, 60 to 75 minutes per day, seem to eliminate the increased risk of death associated with high sitting time”. 

However, the study also said that “this high activity level attenuates, but does not eliminate the increased risk associated with high TV-viewing time”. 

“When the authors excluded all those who reported any disease at baseline and only examined those who were healthy, this association completely disappeared.”

He told Africa Check he thinks the meme’s claim “is unsubstantiated”. 

Conclusion: No evidence for 50 per cent higher death risk claim, but do exercise more

A “medical” Facebook page of unclear origin claims that sitting for over 11 hours a day means you have a 50 per cent chance of dying within the next three years.

Experts told Africa Check that while high sitting time is a health risk including for premature death, no study has measureds this death risk as 50 per cent. 

Further, physical activity significantly reduces the risk of premature death. More research is needed into this, but the message is clear -any type of exercise, whether light or intense, is beneficial. 

This report was written by Africa Check, a non-partisan fact-checking organisation. View the original piece on their website.