Sitting down for hours could invite cardiac disaster

London, Aug 10, 2010 :

Hours spent sitting on chairs could invite cardiovascular disaster, says a study.

Men who sit for 23 hours a week have a 64 percent greater chance of dying from cardiovascular disease than those who spend only 11 hours sitting.

US research published in Circulation found an 11 percent increased risk of death from all causes for every extra hour of TV viewing (i.e. sitting down) a day, reports The Daily Mail.

How can this be? US researchers have found that lipoprotein lipase - a molecule that helps the body process fat - is released only when leg muscles are tensed, for example when you are standing or walking.

The implication is that when you sit, a crucial part of your metabolism slows down.

"Even if someone has a healthy weight, sitting for long periods still has an unhealthy influence on their blood sugar and blood fats," says Professor David Dunstan, who authored the study.

This means you can run for an hour every morning, but if you spend the rest of the day slumped in your seat, many of the health benefits are cancelled out.

The news was worse for women; those who sat more than six hours a day were 37 percent more likely to die than those who sat for fewer than three, regardless of physical activity at other times.

The equivalent figure for men was 18 percent. Any prolonged sedentary behaviour seems to pose a risk to health. As a result, some doctors are calling for a new recommendation to be added to the health advice that urges us to exercise and stand up more.

"If you stand up, you're far more likely to walk around," says James Levine, professor of medicine at the Mayo Clinic in the US.

Even standing still takes effort.

That's because you tense your leg muscles and use back muscles to keep yourself upright. You shift your weight from leg to leg. You stretch and fidget. Standing burns 10 to 20 percent more energy than resting.

For those used to sitting down all day, it's a pain in the neck. Literally.