By Anna Sharratt, BrighterLife.ca
Prolonged sitting can raise your chances of developing a serious illness — and it may take more than a once-a-week workout to reduce the risk.
Toronto lawyer Patrick Simon sits a lot. “I sit for 10 to 12 hours per working day,” says Simon, 38. “I try to take walking breaks, but often I will remain seated without getting up for up to three hours at a stretch, and sometimes even longer.”
Simon doesn’t own a car, so unlike many, he walks extensively and rides his bike for at least 45 minutes every day. He would appear to be a poster child for Canada’s Physical Activity Guidelines, which suggest Canadians exercise 30 to 60 minutes a day, every day.
But new research published in the Annals of Internal Medicine (Sedentary Time and Its Association With Risk for Disease Incidence, Mortality, and Hospitalization in Adults: A Systematic Review and Meta-analysis) says otherwise. In the meta-analysis, a review of 47 studies on sedentary habits conducted by researchers at the University Health Network in Toronto, scientists found that the longer people sit during the day, the higher their risk of heart disease, diabetes, cancer and premature death. And regular exercise — though it reduces the risk — doesn’t save you.
“Prolonged sitting is linked to a 15%-to-20% higher risk of death from all causes,” says senior author Dr. David Alter, senior scientist, Toronto Rehab, University Health Network (UHN), and Institute for Clinical Evaluative Sciences, and associate professor of Medicine, University of Toronto. “Beyond four hours [of sitting], the risks really began to accumulate.”
Alter says that even in people who worked out for the recommended 30 to 60 minutes a day, the risks for diseases were still there — though less than for those who didn’t exercise. While the reasons for the health hazards of sitting times remain unclear, he says that sitting for eight to 10 hours after working out in the gym for an hour significantly reduces the benefits of the gym time.
Not enough calories burned
Alter’s findings may be likened to an examination of the number of calories burned doing an exercise routine at the gym — say 40 minutes on a treadmill — versus the amount of calories in a typical breakfast. Let’s say you burn 500 calories by running; that would be erased by a 500-calorie breakfast sandwich and double double. One cancels out the other. “We don’t burn as many calories as we think we do,” says Alter.
And the calories you don’t burn become dangerous. “The calories that we don’t burn turn to fat, which is toxic to our bodies,” he says. He calls the condition “metabolic toxicity.”
Alter says the take-away from his research is that people need to work in small bursts of light activity — such as walking the dog or taking the stairs instead of the elevator — throughout the day, breaking up the long stretches of sitting. And it’s all about moving and burning calories.
“We can double our calorie burn by standing instead of sitting,” says Alter. He suggests people work exercise into their daily routines, such as standing at work stations, or finding new ways of working out while performing other tasks, such as doing exercise moves while watching TV.
He practised what he preaches, doing his emailing and manuscript-writing while cycling on a stationary bike. “An hour later, I’ve burned 1,000 calories.”
Though Alter says more research is needed to zero in the “golden nugget” of the ideal intervals for movement, the more movement the better. And he admits that how you integrate light activity into your daily routine will depend on the state of your health and your doctor’s recommendations.
“I think of this as a call to action,” he says. “There are different solutions for everybody.”
Patrick Simon says he will be changing things up. “It’s very worrying,” he says. “It makes me want to re-think my entire work routine.”