There's no question that regular exercise is essential to health. For the vast majority of our evolutionary history, we've had to exert ourselves -- often quite strenuously -- to get food, find shelter and simply survive. We naturally spent a lot of time outdoors in the sun, walking, hunting, gathering, and performing various other physically-oriented tasks. We had no concept of this as "exercise" or "working out." It was just life.
Things are different today. Most people in modern societies spend the majority of their time indoors, sitting on their butts (like you're probably doing right now). The typical U.S. adult is sedentary for 60 percent of their waking hours and sits for an average of six hours per day (and often much more, in the case of those who work primarily on computers). In fact, being sedentary is now the norm and exercise is primarily seen as an intervention -- something we do to guard against the negative impacts of a sedentary lifestyle.
An Epidemic of Sedentary Behavior: The Perils of Too Much Sitting
This increase in sedentary time and decrease in physical activity has profoundly impacted our health. Too much sitting is associated with numerous problems, ranging from weight gain, to osteoporosis, to cardiovascular disease. For example, research has shown that:
- Sitting decreases the activity of an enzyme called lipoprotein lipase (LPL), which helps burn fat.
- Too much sedentary time decreases bone mineral density without increasing bone formation, which raises the risk of fracture.
- Excess sitting increases blood pressure and decreases the diameter of arteries, both of which make heart disease more likely.
Even worse, too much sitting could shorten your life. Studies in the U.S., Canada, Australia and Asia have all found an association between increased sedentary time and the risk of early death. These associations were independent of traditional risk factors such as smoking, blood pressure, cholesterol levels, waist circumference and diet.
The "Active Couch Potato": Why Exercise Isn't Enough
I'm sure this isn't news to you; most people are aware that physical activity is essential to good health. But what you may not know is that too much sitting time is harmful even if you're getting enough exercise.
This means you could be meeting the recommended guidelines for exercise (i.e., 30 minutes of moderate to vigorous activity, five days a week), but still be at higher risk of disease if you sit for long periods each day. In fact, a large study involving over 100,000 U.S. adults found that those who sat for more than six hours a day had up to a 40 percent greater risk of death over the next 15 years than those who sat for less than three hours a day. Most importantly, this effect occurred regardless of whether the participants exercised. Some research even suggests that people who exercise intensely (like marathon runners) are more likely to be sedentary when they're not exercising. They may assume that their training regimen protects them from the harmful effects of too much sitting when they're not exercising. It doesn't.
In industrialized societies, this "active couch potato" phenomenon has become the norm rather than the exception. If you work in an office, commute by car and watch a few hours of TV each night, it's not hard to see how you could spend the vast majority of your waking life (up to 15 hours!) sitting on your butt. This is far outside of evolutionary norms for humans, and has serious consequences for our health.
Move Like Your Ancestors: Become an "Organic Mover"
We've established that 1) too much sitting is harmful, and 2) exercise alone isn't enough to reverse the harmful effects of too much sitting. It follows, then, that for optimal health we should reduce sitting time and increase "non-exercise" physical activity. The best way to achieve this is by embracing what I call "organic movement": incorporating physical activity throughout your day in addition to performing distinct periods of exercise. This mimics the ancestral pattern of activity that humans are biologically and genetically adapted to.
In general, I recommend standing or walking for at least 50 percent of the day, and not sitting for more than two hours at a time without taking a short standing or walking break. If you work in an occupation that involves sitting for long periods, here are a few ways to accomplish this:
- Work at a standing desk. Many employers permit this now, and more will follow once they understand the potential benefits in terms of reduced absenteeism, lower health care costs and higher productivity in their employees.
- Work at a treadmill desk. If you want to take a standing desk to the next level, and you work at home or have a progressive employer, try a treadmill desk. (I use one of these in my home office, and it has changed my life. Read this post for more info.)
- Walk or bicycle to work. This isn't always possible, but with a little creativity it often is. If you live too far away to walk or ride exclusively, consider driving part of the way and walking or cycling for the remainder.
- Take a standing or walking break. Stand up for at least two minutes every hour. If possible, take a brief walk or do some light stretching. Even short breaks like this can make a big difference. If you have trouble remembering to do this, try setting an alarm on your phone each time you sit down again, or use an app like Time Out (Mac) or Workrave (Windows).
- Stand up at meetings. If you're worried about what your colleagues might think, just tell them you have a bad back!
- Sit more actively. Sitting inactively in a chair isn't the only way to sit. Consider sitting on a yoga ball for periods of time instead of a chair, or place an "active sitting disc" on your chair and sit on that. Both of these options will force you to make small postural adjustments while you're sitting, which mitigates some of the harmful effects of being sedentary. These micro-movements can add up to a significant expenditure of calories throughout the day.
Now I'd like to hear from you. Have you taken steps to reduce your sitting time? If so, what benefits have you noticed? If you're still sitting for long periods each day, how might you take steps to increase your activity?
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