The dangers of “over-sitting”–spending hours a day in your office chair
or comfy chair/sofa at home–are being born out by a growing list of research
studies, all of which paint a bleak picture.
This month another study published in the October issue of The
British Journal of Sports Medicine adds to the macabre chorus.
Researchers used data from the Australian Diabetes, Obesity and Lifestyle
Study, a large, continuing survey of the health habits of roughly 12,000
Australian adults. The survey asked participants questions about overall
health, existing illness, exercise, smoking, and diet, as well as how many
hours per day in the previous week they had spent sitting in front of the
television. (The issue here is not simply watching TV, of course, but sitting
while watching.)
According to the survey data, in 2008, the year that the researchers
chose as their benchmark, Australian adults collectively viewed 9.8 billion
hours of television. Using actuarial tables and adjusting for smoking, waist
circumference, diet, exercise and other variables, the research isolated how
much time all of the TV watching was chipping off study participants’
lifespans.
The result: every hour of television watched after the age of 25 reduces
the viewer’s life expectancy by 21.8 minutes. Viewed more comprehensively, the
study suggests that an adult who spends an average of six hours a day watching
TV over the course of a lifetime can expect to live 4.8 years fewer than a
person who doesn’t routinely plant themselves in front of the telly.
The especially troubling finding of this and similar studies is that the
result doesn’t seem to be improved by regular exercise. If you sit for hours a
day, and exercise an hour a day, you are still at risk.
Authors of another recent study in the journal Diabetologia, which reviewed data from 18
studies involving 794,577 people, conclude that the average adult spends 50 to
70 percent of their time sitting. This study covered not only leisure time
watching TV, but also time spent sitting at work.
The researchers then cross-referenced sitting time with a variety of
health problems, and found that those who sat the most had a 112 percent
increase in their relative risk of developing diabetes; a 147 percent increase
in their risk for cardiovascular disease; and a 49 percent greater risk of
dying prematurely. Each of these results hold true even if the sitters
regularly exercised. [Source: New York Times, October 17, 2012]
None of these results should be interpreted to mean that exercise isn’t
important — it’s extremely important for overall health. But, exercise alone is
not enough to counter-balance the damage done by sitting for the majority of
our waking hours.
How much sitting is too much? According to the authors of the Australian
study, sitting four or more hours a day puts you in the “risky” category.
That’s hard news for most of us who spend much more than that at office jobs,
to say nothing of leisure time.
