This Will Kill You
Do you know someone who’s had a heart attack? Do you know someone at risk of a heart attack? Do you have a sedentary job, where you sit more than you stand, holding meetings, doing paperwork, using the computer, often for hours? If that’s you, then you do know someone at risk, and VERY well.
As an exercise physiologist, I train heart attack survivors and people with heart disease, and I have seen men and women of all ages, from 26 to 62, from millionaire businessman to assembly line specialist, all brought to the same level, by the same disease, by the same lifestyles. And I have something very important to tell you.
Being sedentary kills you.
Of course people who don’t exercise are less healthy right?
Well guess what? Sitting too much is not the same as exercising too little.
The American College of Sports Medicine, recommends people exercise daily for an hour. In the past, if you met this criterion, you were considered physically active. But we’ve had to become stricter in our definition now. Because strictly speaking, sedentary means using very little energy. And bluntly speaking, it’s how long you spend sitting continuously on your butt.
Research has shown that if you sit for hours, you are at risk REGARDLESS of how much exercise you do. Peter Katzmarzyk et al conducted a prospective study(1) of 17,000 Canadians, examining the link between time sitting down, and death. People were divided into those who hardly sat at all, those who sat about ¼ of the day, ½ of the day, and almost all day. What they found was astounding. Those who sat the longest per day, were 50% more likely to die during the follow up period even after factoring in things like smoking, overweight, alcohol and inactivity!
Another study on Australians found that regardless of the same factors, each hour you watch TV is associated with an 11% increase in risk for death from all causes. To put it simply, if you and I both weighed the same, exercised the same amount, didn’t smoke, took the same amount of alcohol, and were of the same age and gender… if I sit more hours per day than you, I have a higher risk of death.
Essentially, even if I exercised every day for an hour, but for the rest of the day I sat on my posterior for 7 hours, I’M AT RISK!
And so are you.
We think one effect of sitting all the time is that the body actually changes. Special proteins in your body regulate blood sugar and fat. These are reduced with long continuous periods of inactivity. Your muscles can’t soak up fat and sugar as well, so more is left circulating in your blood. In fact, 5 days bed rest can increase bad cholesterol by 35%!
Sedentary behavior may also stimulate eating. How often do you snack on something when you’re in front of the computer? A small chocolate here, a little cracker there…
Research also shows that activities like studying, managing projects, and accounting, increases sugar intake, possibly because mental work requires glucose, so you find a way to give your brain that.
So important are these discoveries that a special field – sedentary physiology – has sprung up to investigate the many things we still don’t know. But what we do know for sure: Being sedentary kills you.
What Can We Do?
So if exercise isn’t the answer, what can we do?
The key lies in this question.
Does it make any difference if I sit 8 hours straight, or if my 8 hours are interrupted?
And the answer seems to be… YES!
A recent study by Genevieve Healy(2) found that those who took more breaks showed better blood glucose and cholesterol levels. And these breaks were brief and low intensity, such as short walk to restroom, or just getting up to stand! This was the case even if total amount of sitting time was the same between all individuals!
The Take Home Message?
In the past, our ancestors WORKED for their food. Out in the wild, walking and chasing on foot, hunting and hurling spears.
Today we WAIT for our food. Inside the office, sitting down, chasing paper and hunting for staples and hurling abuse.
We can’t expect to change the nature of our jobs. BUT… we CAN break the sitting pattern. Get out of your chair once every hour to walk to the washroom, get a drink. While watching TV, get up during the break, stretch. Take frequent, short breaks as much as you can. It’s not about exercise. Don’t be complacent just because you exercise daily.
It’s about giving your butt a break.
But… don’t have a kit kat.
1. Sitting time and mortality from all causes, cardiovascular disease, and cancer. Katzmarzyk PT, Church TS, Craig CL, Bouchard C. Med Sci Sports Exerc. 2009 May;41(5):998-1005
2. Breaks in sedentary time – beneficial associations with metabolic risk. Healy GN, Dunstan DW, Salmon J, Cerin E, Shaw JE, Zimmet PZ, Owen N. Diabetes Care. 2008 April; 31 (4): 661-666