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On average, we spend more than half of our waking hours sitting down: working at a computer, watching television, traveling in a car, or doing other sedentary things such as reading or chatting with friends. But long stretches of uninterrupted sitting have a range of undesirable effects that may harm your heart, says Dr. Beth Frates, who directs wellness programming for the Stroke Research and Recovery Institute at Harvard-affiliated Spaulding Rehabilitation Hospital.
"Sedentary behavior affects your body in many different ways, even down to the molecular level," she notes.
In recent years, research has shown that compared with people who move more throughout the day, those who sit for long stretches of time tend to have higher levels of markers linked to heart disease risk.
For example, they have bigger bellies, higher levels of triglycerides (the most common type of fat in the blood), and trouble controlling their blood sugar. When you sit for long periods without moving your muscles, those tissues become less sensitive to insulin, the hormone that regulates blood sugar. This so-called insulin resistance raises your risk for type 2 diabetes, which is closely linked to heart disease.
In fact, compared with people who spent less time sitting, those who sat for prolonged periods had higher rates of heart disease and were more likely to die sooner regardless of cause, even if they exercised regularly. That's according to a 2015 review article that pooled data from 47 studies that looked at people's active time, including everything from leisure activities to vigorous exercise. "Even if you exercise for an hour a day, you're still at higher risk for heart disease if you're sitting for eight hours every day," says Dr. Frates.
The danger may arise in part from other habits linked to excessive sitting. If you're binge-watching TV, for instance, you may be tempted to munch on sweet, salty, fatty snacks, making you more prone to gain weight, says Dr. Frates. Surveys suggest that the typical office worker sits for at least 10 hours a day. Spending long, uninterrupted hours in front of a computer screen can create tension in your neck and shoulders. This physical stress may trigger mental stress, thereby raising blood pressure and, in turn, risk of heart disease. Sitting a lot also tends to cause stiffness in your hip flexors, the muscles at the top of the leg where the thigh meets the pelvis. Inflexible hip flexors (especially if you're older) can leave you more vulnerable to falls and injuries — and therefore unable to exercise at all.
The good news is that several small studies show that standing more (or getting up and moving around periodically) may modestly improve insulin resistance, triglyceride and cholesterol levels, and even blood pressure. In 2015, an international group of experts published a health guidance statement recommending that office workers in the United Kingdom stand or do light activity (such as walking) for two to four hours per day. That's probably a good idea for all of us, even those who don't do full-time office work, notes Dr. Frates.
Anyone who spends long hours at a computer should consider getting a standing desk to use for a couple of hours a day, she says. There's no need to buy a fancy one; you can purchase a portable, fold-up model that sits on top of your regular desk. Designate set times to stand each day—perhaps one hour in the morning and another in the afternoon.
Other simple approaches to encourage more movement include a portable pedaling device, which you pedal with your legs or arms while sitting, or sitting on an exercise ball. Dr. Frates also encourages her patients to revisit low-impact activities they enjoyed when they were younger, like dancing or playing Ping-Pong. "One 74-year old woman I was working with got me into hula-hooping," says Dr. Frates. "Think outside the box, and try different ways to move more throughout your day."
Here are five additional suggestions to reduce your sitting time:
1. Set a timer out of arm's reach. Using your smartphone or a regular kitchen timer, set an alarm to go off every 60 minutes during the day when you tend to sit for long periods of time. Put the device across the room to force yourself to get up to turn it off.
2. Pace or tidy up during phone calls. Whenever you're on the phone, stand up. Try to walk back and forth or in circles while you talk. Or use a hands-free headset and straighten up your office or do some light housework while you chat.
3. Move a little while you watch TV. According to a recent Nielsen report, the average American watches five hours of television a day, and that amount increases as people age. Use the two- or three-minute commercial breaks while you are watching TV to stand up. March in place, swing your arms, or do some squats or leg lifts.
4. Catch up with friends while walking. Social visits often tend to be sedentary, so instead of meeting a friend for coffee or lunch, take a walk instead. Or take a stroll before or after a dinner date.
5. Take the long way. Whenever you drive somewhere, park in a spot farther from the door to get in some extra steps.