Studies in recent years have made a connection between time spent in front of a TV or computer and poor health. In fact, a study of this sort made news earlier this month when it found that people who enjoy hours of screen-based entertainment on a daily basis are at a hugely increased risk for heart disease and even death. But other research verifies what common sense would tell you: it's the sitting, not the screen. And all you need to do is stand up.
The first study, published in the January 18th issue of the Journal of the American College of Cardiology, finds a strong link between screen-time and poor health. The study looked at 4,512 adult respondents to the 2003 Scottish Health Survey. The authors examined the link between self-reported time in front of a TV, computer or video game and the subjects' health outcomes. Their finding: "People who spend excessive amounts of time in front of a screen—primarily watching TV—are more likely to die of any cause and suffer heart-related problems," said Dr. Emmanuel Stamatakis of the University College London Department of Epidemiology and Public Health. "Our analysis suggests that two or more hours of screen time each day may place someone at greater risk for a cardiac event."
How much more at risk? The researchers found a 48% increase in risk of death from any cause among those who spent two or more hours per day in front of a screen. And they found a nearly 125% increase in risk of cardiovascular events (read: heart attacks) in the same population. Ouch. The study also excluded people with existing health conditions, so it wasn't poor underlying health that made people sit in front of the tube to begin with. Worst of all, Stamatakis said, "According to what we know so far, these health risks may not be mitigated by exercise, a finding that underscores the urgent need for public health recommendations to include guidelines for limiting recreational sitting and other sedentary behaviors, in addition to improving physical activity."
What's going on here? It's not some magic of the TV or the computer, another study suggests. Rather, the problem is the inflammation that is caused by sedentary behavior—by sitting. Even if you get up and run a marathon, having sat for an extended period will have taken a physical toll. A study published in the January 12 issue of the European Heart Journal studied an ethnically diverse population of 4,757 respondents to the US National Health and Nutrition Examination Survey from 2003 to 2006. This time the data were not self-reported: participants wore a device that tracked their activity during waking hours. The researchers also took data on waist circumference, blood pressure, cholesterol levels and C-reactive protein concentrations (a basic indicator of inflammation) as well as other blood markers of baseline health. And what they found is fairly simple: more sitting increases the risk factors for poor health (i.e., bigger waists, lower levels of HDL cholesterol, higher levels of C-reactive protein, elevated fats in the blood). But the really interesting result was that even a little bit of moving around goes a long way.
Study participants whose monitors showed they got up regularly during otherwise sedentary periods were able to reduce these health red flags. Here's how study author Dr Genevieve Healy, a research fellow at the School of Population Health, The University of Queensland, Australia, described her findings: "Our research showed that even small changes, which could be as little as standing up for one minute, might help to lower this health risk. It is likely that regular breaks in prolonged sitting time could be readily incorporated into the working environment without any detrimental impact on productivity, although this still needs to be determined by further research. 'Stand up, move more, more often' could be used as a slogan to get this message across."
The fact is, you want to break up your sedentary periods where they're most likely to occur: not just at home in front of the TV, but at work behind your desk. Here are a few of Healy's suggestions: take phone calls standing up; walk to see a colleague in your office rather than phoning or emailing; use a bathroom on a different floor; put things like trash cans and printers far from your desk, in a spot you'll need to walk to to use them.