Not literally, of course. It's not that your desk chair and your comfy couch are getting together behind your back and coming up with nefarious plots against your life. It's what you do with your desk chair and couch that's putting your life at risk – you sit in them. Sitting is the thing that can cut years off of your life.
The case for sitting too much being bad for you
Sadly – and please understand that this applies to me as well, since I spend far too much of my day sitting in front of a computer writing articles – the evidence seems to be mounting that remaining seated for large portions of one's day is bad for you. In one study published recently in the journal BMJ Open, researchers found that sitting for more than three hours per day reduces your life expectancy by two years. Watch TV for two hours a day, and that cuts an additional 1.4 years off of your life expectancy.
Another study conducted in Australia found that watching TV cuts 22 minutes from your life. Extrapolating from their findings, that study's authors suggested that men who watched no TV in their adult lives would add 1.8 years to their lives, and women would add 1.5 years.
Sitting too much, and the essentially sedentary lifestyle that accompanies it, has also been linked to numerous diseases. In a study published in the journal Diabetes Care, Australian scientists asked subjects to either sit for seven hours a day or, on alternate days, get up every 20 minutes and walk at a comfortable rate on a treadmill for two minutes. Performing blood tests, they found that when the volunteer subjects stayed seated for seven hours, the levels of both blood sugar and insulin spiked and went out of control. Whereas if they just got up and walked on the treadmill periodically, their blood sugar and insulin levels remained stable. Other studies have confirmed their findings, to the point that inactivity is now considered by health authorities to be one of the primary causes of Type 2 diabetes.
There are additional deleterious effects of sitting too much that affect your muscles and your metabolism. Sitting for long periods of time causes the electrical activity in your muscles to stop, which causes metabolic changes that reduce your body's ability to burn calories to a third of what it would be if you got up and walked around periodically. Just standing burns hundreds more calories per hour than sitting does. So the scientific evidence is pretty clear – sitting too much reduces your life expectancy, makes you sick, and makes you fat.
What can we do about it?
This is a good question. Those of us who work in offices can rarely work at a "standing desk," except in very progressive and health-conscious companies. We're expected to sit at our desks for much of the day; that is the very thing that is in many cases used to measure our contribution to the company and our productivity. Disappear for long periods of time and your employers are going to start getting the idea that you're a slacker.
The answer to this dilemma may be found in the second Australian study discussed above. Just get up and move from time to time during the day. Instead of sending your documents to the printer at arms' reach, send it to one at the other end of the room, or even better, a printer on another floor. That gives you an excuse to get up and retrieve your documents. We all know that it's good for us to drink enough water during the day, but rather than doing that by keeping a bottle at your desk, use a glass and get up several times a day to refill it at the office water cooler or fountain. Stand up while talking on the phone. If much of your day is spent in meetings, ask your boss and colleagues whether they'd be willing to have "walking meetings" from time to time. Be creative.
At home, consider alternatives to spending your evenings as a couch potato. Go to the gym, or go for a run, or just do some yard work or house cleaning. Or get a dog; I can testify that they just won't let you sit around all day, and that several times a day they'll come over and remind you that you need a walk, and agree to accompany you on it. Again, be creative. I have one friend in the US who canceled his Cable TV contract, made no other changes to his lifestyle or diet, and lost ten pounds.
I will finish by admitting to what would be the irony of someone like myself sitting in front of a computer, writing an article about the perils of sitting too much while sitting. So to preserve my journalistic integrity, I have written this entire article while standing. It may not increase my life expectancy, but at the very least it makes me feel like less of a "Do as I say, not as I do" writer.