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If your idea of a relaxing evening is plopping in front of the TV for a few hours, beware. Vegging out to your favorite shows could be increasing your risk of death from heart disease.
People who sit and watch more than four hours of television a day have an 80 percent increased risk of death from cardiovascular disease, according to study in the journal Circulation by the American Heart Association. The study analyzed the TV-viewing habits of nearly 8,000 Australians over a period of 6.6 years. The findings suggest that every hour per day spent watching TV increases the risk of death from heart disease by 18 percent.
The study looked specifically at watching TV, but correlations can be made with all other sedentary activities, like driving and sitting at a desk, says study leader David Dunstan, Ph.D., head of the Physical Activity Laboratory in the Division of Metabolism and Obesity at the Baker IDI Heart and Diabetes Institute in Australia.
"Prolonged sitting is the problem, not the television itself,?" says Dunstan. "The amount of calories that we burn while we are sitting watching television is almost similar to the calories that we burn while we're sleeping. So, if we are spending prolonged periods sitting, we are reducing our capacity to burn calories, and, of course, that is a major factor in weight maintenance."
Extra pounds increase a person's risk of heart disease. Also, prolonged sitting decreases the body's ability break down fat, which can raise cholesterol. And considering that many Americans' daily routine consists of moving from sitting in the car to sitting at a desk to sitting on a couch, our lifestyle could be increasing our risk of disease. Fitting a visit to the gym into the middle of all that sitting might not undo the damage.
"Even if we get that 60 minutes of exercise per day, if we sit for the remaining 15 (waking) hours in the day, that sitting may override the good benefits that you derive from doing exercise," Dunstan says.
To reduce our risk of heart disease, we need to stop relegating exercise to a half-hour chunk of our day and instead make movement a constant habit. People underestimate the importance of minor activities, Dunstan says. Walk to a coworker instead of email or call. Even standing requires more calories and muscles than sitting.