Can sitting for too long really kill you?

Should you be concerned about sitting too much? We explore the health effects of a sedentary life, and offer tips on how you can avoid the harmful effects of sitting for too long.

By Jackie Middleton

Can sitting for too long really kill you?
iStockphoto.com/bholland
How long did you sit today? Sitting seems to have become a way of life. If you're like most Canadians -- enduring lengthy commutes to work by car or train, relying on computers on the job and spending your evenings couch-bound in front of the television -- then you're racking up plenty of hours sitting down.

Unfortunately, the end result is anything but pretty. Studies from around the globe have found that excessive sitting and reclining put you at an increased risk of heart disease, type 2 diabetes and early death -- even if you exercise regularly and meet Canada's physical activity guidelines.

According to Mark Tremblay, the director of the Healthy Active Living and Obesity (HALO) Research Group at the CHEO Research Institute in Ottawa, Canadian adults spend, on average, three-quarters of their waking hours each day sitting or reclining. This static behaviour is rubbing off on your kids, too. On average, Canadian children spend two-thirds of their daytime hours sedentary.

It's not surprising that such worrisome statistics have prompted many Canadians to stand up and take notice.

Should you be concerned?
The fear factor surrounding sedentary behaviours began gathering momentum in 2012 -- especially in the media. Exposing data from recent scientific studies, headlines screamed that sitting at your desk could kill you.

But how do you know when to separate the hype from the truth? And if a mainly sedentary lifestyle is dangerous, how can you adopt healthy changes?

Before you abandon your office chair for good, it's important to understand the hype and why scientists, physiologists and health experts have been consumed with the idea of reducing your time spent sitting. With obesity steadily increasing, researchers began to compare the lifestyles of previous generations to our own and they made an important discovery.

''In the past, most people didn't sit at work. A hundred years ago they may have had agricultural-based lifestyles, were tradespeople or did tasks that involved standing and moving,'' says Tremblay.

What has changed? The arrival of technology.

''We drive when we would have walked or biked. We sit in front of a screen when we would have shovelled, nailed or carried. All of our discretionary time is in front of a computer or television screen,'' he says.

In the last 50 to 75 years, our lifestyles have become physically stagnant. Can you remember the last time you walked to work, got up from the couch to change a TV channel or out of the car to open your garage door?

While you might consider these physical movements insignificant to your overall health, researchers have found that the opposite is true. These activities -- and many others like them -- used to be repeated on a daily basis. Cut these tasks out of your day and replace them with technologically assisted seated behaviours (driving to work, using a TV remote or automatic garage opener, etc.) and you're moving substantially less than your grandparents did.

The toll on your body
When your body spends extended periods of time inactive, its systems become less efficient and begin to falter.

''The more you sit, the less robust your tissues -- your heart, lungs, muscles -- become,'' says Tremblay. ''They go into hibernation mode and they atrophy. Over time, they decay,'' he explains.

Your metabolism of fat and glucose becomes sluggish, your circulation becomes compromised and unhealthy processes that are only connected to sedentary behaviour kick into gear. Premature death caused by cardiovascular disease and diabetes has been linked to a sedentary lifestyle, and the relationship between other illnesses and sedentary lifestyles are being investigated.

Unfortunately, daily workouts don't erase this health concern. According to Tremblay, only 15 per cent of Canadian adults and seven per cent of children meet Canada's physical activity guidelines. When you examine a typical day, ''the guidelines represent roughly one to four per cent of the total 24-hour period,'' he says.

So what are you doing for the remaining 96 to 99 per cent of your day? Being primarily sedentary.

How you can make changes
Thankfully, it's easy to adjust your sedentary behaviour by making small changes to your daily activities. Try using a stand-up desk or delivering messages to your coworkers in person rather than using email.

''When your phone rings, stand up. Have walking meetings. Get rid of your automatic garage door opener. The more variety that you can introduce, the better,'' says Tremblay. ''Don't stand too long; don't sit for too long. Everything in moderation. Sitting, standing and walking in various combinations for various lengths of time keep your skeleton, muscles and organs healthy.''

Best of all, switching postures and small physical activities throughout your day doesn't require workout gear or a fitness club membership.

''Evidence shows that you can actually improve your health [by limiting sedentary spells],'' says Tremblay.

Despite all of the negative press about sitting, Tremblay stresses that we shouldn't demonize the practice.

''We can't be up and about all of the time either. It would cause back pain, just like sitting too much.'' The key, he says, is to ''introduce variety and interruptions to your immobility as often as possible. It's in your best interest.''

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