People who spent a lot of time sitting at a desk or in front of a television were more likely to die than those who were sedentary a few hours a day, according Australian study that looked at death rates during three-year period.
Researcher whose result appeared in the Archives of Internal Medicine, found that the link between too much time sitting and shortened lives stuck even when they accounted or how much moderate or vigorous exercise people got, as well as their weight and other measures of health.
That suggest that shifting some time from sitting to light physical activity such as slow walking or active chores, might have important long-term benefits, they added.
“When people messages about how much physical activity they should be doing, we also need to talk to them about reducing the amount of hours they spend sitting each day” said Hidde van der Ploeg, the new study’s lead author from University of Sydney.
Of more than 200,000 adults age 45 and older, Van der Ploeg and her colleagues found that people who reported sitting for at least 11 hours a day were 40 percent more likely to die during the study than those who sat less than four hours daily.
That does not however, prove that sitting itself cuts people’s lives short, she noted, adding that there could be other unmeasured differences between people who spend a lot or little time sitting each day.
The team surveyed about 220,000 people from New South Wales, Australia between 2006 and 2008, including questions about participant’s general health and any medical condition they had, whether they smoked and how much time they spent both exercising and sitting each day.
The the search team tracked responders using Australian mortality records for an average of almost three years, during which 5,400 – between 2 and 3 percent – died.
They found that the extra risk tied yo sitting held up regardless of whether people were normal weight or overweight, how much time they spent working out and whether they were healthy or bad preexisting medical conditions.
Van der Ploeg said too much sitting may affect blood vessels and metabolism by increasing fats in the blood and lowering “good” cholesterol levels.
“When you are standing or walking , your leg muscles are constantly working, which helps to clear blood glucose and blood fats from blood streams” she said. “If you are sitting, this is not active”.
The findings are consistent with other recent studies suggesting health consequences from too much sitting, said Mark Tremblay, an obesity and activity researcher at the Children’s Hospital of Eastern Ontario in Canada.
“Sitting or reclining , especially in front of screens, is bad for you regardless of your age” said Tremblay , who was not involved in the study.
He added that even though people tend to think they are OK as long as they work out a certain amount a day, that is not necessarily the case.
“Getting 30 minutes of physical activity five times a week is not insurance against chronic disease”.
Both he and Van der Ploeg said there were ways that even people who have jobs involving a lot of desk work could train themselves to regularly interrupted sedentary behavior, such as standing while on the phone or holding a stand-up meeting.
“Make sure the fax machine is four steps away from you , not within reaching distance”. Tremblay said.
“Drink enough water that you have to pee four times a day. Stand up, stretch, walk around a little bit, say ‘hi” to your friend in the next cubicle next door” – Reuters as published in the Jakarta Post 31 March 2012