Death by TV?

Australian researchers who tracked the TV viewing habits of 8,800 people over a six-year span have some sobering statistics for people who love the tube too well: (1) If you watch TV more than two and up to four hours a day, your risk of dying from cardiovascular disease increases by 19 percent. (2) If your viewing habit is more than four hours a day, your risk of death from cardiovascular disease skyrockets by 80 percent.

    In fact, every hour beyond two hours of sedentary viewing ups the risk by 18 percent.

    The Australians, led by David Dunstan from the Baker IDI Heart and Diabetes Institute in Melbourne, also found that even if heavy TV viewers routinely exercise 30 or 45 minutes a day, they are just as susceptible to the higher risk of cardiovascular disease. The reason why, the researchers think, is that humans are not built to sit for long periods. Prolonged inactivity affects how the body metabolizes fats and other substances that increase cardiovascular risks. They add that although common wisdom says that regular “heavy sweat” exercises, like treadmill runs, bike rides, or jogging, can counter the ill-effects of too much TV, they really can’t.

    What’s needed, the researchers say, is the kind of ordinary “walking around” things that people do all day long-unloading the dishwasher, fixing a minor leak, pushing a shopping cart at the supermarket, walking the dog, mowing the lawn-any routine activity that keeps the body in motion and helps it metabolize substances that can quickly accumulate from inactivity.

    In short, even heavy TV viewers should find ways to keep moving while they’re watching.  These can include standing and folding laundry while watching, doing stretching exercises or running in place, or changing channels manually instead of with a remote-anything that keeps the body moving and flexible.

    And it’s not just sitting in front of the telly that can contribute to cardio risks. Riding a commuter bus or train and then sitting at a desk for eight hours is an equivalent form of sedentary behavior. Some people mitigate their risks by walking up and down train aisles or standing on bus rides, using their constant small adjustments to bumps and jerks as a low-key form of exercise.

    At the office, some people use adjustable-height desks that allow them to stand as they work, shifting from one foot to another and allowing free blood flow in their legs. 

    Subjects averaged 50 years of age when the study began in 1999-2000.  The study results were recently published in Circulation magazine.