Sitting for long may raise heart disease risk: study

Sitting for too long may increase the risk of developing heart disease and stroke, a new study has warned.
"Regardless of how much physical activity someone gets, prolonged sedentary time could negatively impact the health of your heart and blood vessels," said Deborah Rohm Young, director of behavioural research at Kaiser Permanente Southern California in the US.
Sedentary behaviour may be associated with an increased risk of developing diabetes, cardiovascular disease, impaired insulin sensitivity (linked to diabetes) and an overall higher risk of death from any cause, researchers said.
"There are many important factors we don't understand about sedentary time yet. The types of studies available identify trends but don't prove cause and effect," said Young.

"We don't have information about how much sedentary behaviour is bad for health - the best advice at this time is to 'sit less and move more'," Young said.
Instead of lumping all the exercise into one or two days, the goal is to encourage more consistent activity, Young said.

However, the researchers found that moderate to vigorous physical activity does not cancel out the impact of sedentary time. Even physically active people who spend a lot of their time being sedentary appear to have increased risk.
Sedentary behaviours include sitting, reclining, or laying down while awake as well as reading, watching television or working on the computer.

These "inactive activities" mean energy expenditure is less than or equal to 1.5 metabolic equivalents, or METs.
Light housework or slow, leisurely walking uses about 2.5 METs, moderate to vigorous physical activity usually requires 3.0 or more METs.
Another issue, according to Young, is that it is not clear whether people should replace prolonged sedentary behaviour with simple movement or moderate to vigorous physical activity.
The study was published in the journal Circulation.