The Extreme Dangers of Sitting
James A. Levine, MD, PhD
Being a couch potato has long been known to threaten a person’s health. But now researchers are discovering that it’s much more dangerous than previously thought.
Troubling statistic: Americans spend more than half their waking hours sitting — primarily watching TV, driving and working at a desk.
Important new finding: When Australian researchers recently tracked 8,800 men and women (average age 53) for about six years, they found that for every hour of daily TV viewing, risk for death due to cardiovascular disease increased by 18%. For those who watched TV four or more hours daily, risk of dying from cardiovascular disease was 80% higher than for those who reported watching fewer than two hours daily.
Most surprising: A similar Canadian study of about 17,000 adults found that even among people who are physically fit and have a normal body weight, prolonged sitting, for any reason, was associated with increased health risks, suggesting that sitting for long periods may cancel out some of the health benefits of regular exercise.
THE PROBLEM WITH SITTING
Our bodies are programmed to move. When we spend most of our waking hours sitting, our health suffers in various ways. Examples…
Sluggish central nervous system. Sitting causes your central nervous system to slow down, leading to fatigue. Three weekly sessions of low-intensity exercise, such as walking at a leisurely pace, which stimulates the central nervous system, reduced fatigue by 65% after six weeks, according to one study.
Weakened muscles. Sitting weakens your muscles (especially those that support posture and are used to walk) and stiffens joints, leading to a hunched posture and increased risk for back and joint pain.
Poor fat burning. The walls of your capillaries are lined with lipoprotein lipase, an enzyme that breaks down certain fats in the bloodstream. Sit for a few hours, and these enzymes start switching off. Sit all day, and their activity drops by 50%.
Increased heart risks. Sitting for long periods, even in people with healthy body weight, will have negative effects on blood sugar and blood fat levels, which may contribute to diabetes and heart disease.
THE “NEAT” SOLUTION
Fortunately, the dangers of prolonged sitting can be countered by engaging in simple, low-intensity movement throughout the day.
Thirty minutes or more of cardiovascular exercise (such as brisk walking, swimming or biking) several days per week is known to help promote good overall health. However, research at the Mayo Clinic has shown that the average American’s biggest health problem is a deficit in activity when formal exercise is not being performed.
Non-exercise activity thermogenesis (NEAT) is the term that is used for the energy that is expended (calories burned) doing everyday activities.
While in previous generations our work and recreational activities involved regularly standing up and moving the body’s muscles, today’s world of cars, desk jobs, TVs and computers has reduced our daily NEAT dramatically.
The solution is to add small amounts of non-exercise-related activity into your daily routine. For example, simply standing up triples your energy expenditure compared with sitting. And since a slow (1 mile per hour) walk triggers more than half the metabolic activity of a brisk (3 mph) walk, a leisurely hour-long stroll burns more calories than an intense 30-minute power walk.
Interesting: We burn just five calories an hour while sitting and 15 while standing.
TO COUNTERACT SITTING AT HOME
With a little forethought, it’s possible to significantly raise your activity level without stepping foot in a gym. Not surprisingly, watching TV and long hours at the computer are among the biggest traps when you’re at home. To develop your own NEAT lifestyle in your home…
Stand up and walk around. Do this every time an advertisement comes on the TV.
Keep a stability ball handy. Since sitting on this kind of large, inflatable ball requires you to shift slightly from side to side to keep your balance, it engages more muscles (especially those in your abdomen and back) than sitting in a regular chair does. Strong abdominal muscles help fight back pain and enhance stability and balance. Stability ball chairs are available from Gaiam (877-989-6321, http://www.Gaiam.com, $120)… and Isokinetics, Inc. (866-263-0674, http://www.IsokineticsInc.com, $65).
Place exercise equipment near your TV. Good choices include a treadmill, stationary bike and/or elliptical trainer. If you watch TV, choose a half-hour show every day and begin using the equipment as the theme music comes on. Continue until the show ends.
Another option: Try a “mini stepper,” a small device with two footpads that lets you step in place against resistance. These machines can be tucked away when not in use. Mini steppers are widely available from such companies as Stamina Products, Inc. (800-375-7520, http://www.StaminaProducts.com, $40 to $170)… and NordicTrack (www.NordicTrack.com, 888-308-9616, $120).
Put your computer on an elevated surface, such as a shelf or stand. This way, you can stand while typing or surfing the Web.
Choose action-oriented video games. If you play video games, opt for an active game (including Wii, which allows you to mimic motions used in sports such as tennis) instead of more sedentary games.
Engage in “active intimacy.” Catch up with your spouse or other family members or friends by talking with them while you stroll around the neighborhood together.
TO COUNTERACT SITTING AT WORK
For a NEAT lifestyle at work…
Stand up when you answer the phone. If possible, pace near your desk for the duration of the call.
Schedule “walking meetings.” This is ideal when you need to meet with just one or two people and don’t need to take a lot of notes.
Cut back on phone calls and e-mails to coworkers. When you need to speak to a coworker, walk to his/her work space. Besides getting you out of your chair, this face-to-face communication style has been shown to improve relationships.
Follow the 10-minute rule. Whenever you’re working at a computer, get up for 10 minutes every hour to stretch your back and legs. Use this time to perform tasks that can be done while standing, such as making phone calls.
Take the stairs. Avoid the elevator when going to and from your office floor.
Park your car a distance (half a mile, for example) from your office. If you take mass transit, get off the bus or subway one or two stops before your destination.
Take a midday walk. Use half your lunch hour for a stroll.
Use a standing desk. It allows you to stand while working. Ernest Hemingway used such a desk. They are available from such companies as Ergo Desk (800-822-3746, http://www.ErgoDesk.com)… and Anthro (800-325-3841, http://www.Anthro.com).
Cost: About $240 to more than $2,000.
Even better: Add a treadmill for less than $1,000 to your work space to create a “walking desk.” Don’t laugh — many people who have done this (using it for four to 12 hours daily) have found that their productivity and concentration have improved along with their health.
Bottom Line/Health interviewed James A. Levine, MD, PhD, director of the Non-Exercise Activity Thermogenesis (NEAT) Laboratory at the Mayo Clinic in Rochester, Minnesota. He is coauthor of Move a Little, Lose a Lot (Crown).