An alarming new study has revealed sitting for too long can increase the risk of an early death, irrespective of how much exercise you do.
The research published in Annals of Internal Medicine found a direct relationship between a person’s total sedentary time and sitting for prolonged, uninterrupted periods, and the risk of early mortality of any cause.
And according to the study’s lead author, Dr Keith Diaz, the longer you sit the greater risk you are at of an early grave.
“We were surprised at just how strong a risk factor sedentary behaviour was for risk of death, particularly even after we accounted for exercise levels,” Dr Diaz, a Columbia University Department of Medicine research scientist, told The New Daily.
“We were also surprised to find that the link between sedentary behaviour and death is even stronger when you sit for long, uninterrupted periods,” he said.
The US-based study was conducted with almost 8000 Americans aged 45 years or older, who wore hip-mounted accelerometers to record their activity levels.
The results found sedentary behaviour accounted for 77 per cent of the participants’ waking hours, equalling 12.3 hours of an average 16-hour waking day.
Over an average follow-up period of four years, 340 of the participants had died.
It also found those who sat for more than 13 hours per day had 200 per cent greater risk of an early death, compared to those who sat for less than 11 hours a day.
Meanwhile, those who sat for less than 30-minute stretches had a 55 per cent lower risk of death than those who sat for extended periods.
“Our study confirmed that sitting increases your risk of death, regardless of whether you exercise or not. So our findings highlight that in addition to exercise, individuals should also be mindful about moving frequently throughout the day,” Dr Diaz said.
“We found that those individuals who frequently kept their sitting periods to less than 30 minutes had the lowest risk of death. So if you’re someone who has to sit for prolonged periods at work or home, we think a simple way to combat the risks of sitting is to take a movement break every 30 minutes.”
Dr Diaz suggested middle-aged and older adults are at greater risk because of their increased sedentary periods.
“It’s likely in part because older adults are more sedentary. As our physical and mental functions decline with age, we become more and more sedentary. This reaps harmful consequences,” he said.
However, Dr Diaz said the findings are not limited to older adults.
“We have no reason to suspect that sedentary behaviour acts any differently in younger adults. It’s likely that sedentary behaviour elicits the same hazardous effects on the body in younger and older adults,” he said.
Reasons behind risk ‘not entirely clear’
Despite the alarming results, the underlying reasons behind the sedentary-behaviour findings remain unclear.
“It is still not entirely clear why sedentary time is such a hazardous risk factor,” Dr Diaz said.
“Some of the most promising evidence suggests prolonged sedentary periods disrupts how our bodies control blood glucose [or blood sugar] levels.
“Other evidence suggests that blood pooling in the legs as a result of prolonged sitting causes damage to the inner lining of blood vessels.”
Meanwhile, other research shows standing at work can have as harmful effects as sitting, with prolonged use of standing desks doubles the risk of heart disease.