Sitting for long periods increases chances of dying earlier regardless of regular exercise

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Washington Post

Tuesday, May 12, 2009

If you sit for too long, you'll die. Or at least you may die earlier than

those who get up and move around during the day, according to a study

published in this month's issue of Medicine & Science in Sports & Exercise.

The study explored the relationship between sedentary behavior (that is,

sitting) and premature mortality by observing a group of more than 17,000

Canadians ages 18 to 90 who took part in the 1981 Canada Fitness Survey.

Survey participants rated themselves on how much time they spent sitting in

any given week: almost none of the time, a fourth of the time, half of the

time, three-fourths of the time, and almost all of the time. During the 12

years that the study followed the subjects, 1,832 of them died. The

researchers found that the mortality rate was almost three times higher

among the least active than it was among the most active.

The effects were consistent regardless of sex, age, smoking status and body

mass index. And they were " independent of leisure time physical activity, "

the researchers said. In other words, sedentary behavior is not the same as

lack of exercise; even physically fit people who exercised regularly still

seem to risk premature death if they sit for prolonged periods during the

day.

The authors noted that people in the United States " spend an average of 55

percent of their day in sedentary pursuits " such as watching TV, eating,

working at a desk and riding in a car. " In addition to the promotion of

moderate-to-vigorous physical activity and a healthy weight, physicians

should discourage sitting for extended periods, " the authors wrote.

Those extended periods, they said, result in " metabolic alterations " that

cannot be compensated for even if the individual exceeds the daily minimum

physical activity guidelines of the American Heart Association.

To reduce your chances of premature mortality by sitting, the authors said,

increase your level of daily physical activity and reduce the time you spend

sitting per day by taking breaks every 60 to 90 minutes.