In 2012 it was rumored that a Taiwanese teen died after gaming for 40 consecutive hours [source: HuffPo]. Death by "Diablo 3"? As it turns out, the tabloids may have gotten one thing right about that story -- apparently when you sit for extended periods of time, the Grim Reaper sits beside you.
When you indulge in just 30 minutes of TV watching -- not even close to 40 hours at a time -- you burn about one calorie per minute (that's the estimate for a person weighing 155 pounds) -- and that's not much; in comparison it's only about a third of the calories that would be used if that time were spent walking, and pretty close to the amount burned during a 30-minute nap (about 23 calories). While the amount of calories burned may seem pretty similar between the two activities, sleep is important for good health and memory, and sitting, well, as it turns out it may be hurting you [source: Harvard Heart Letter].
Think about how often you sit during the day; at the desk at the office, in meetings, in class, at home in front of the TV or game console -- and don't forget about all the time spent sitting in your car or during your daily commute. All those hours add up, and in recent years it's estimated we spend nearly eight hours sitting every day on average -- and some research suggests we actually may be sitting as much as 15 hours every day. Considering we need about eight hours of sleep every night, that leaves some of us with only about an hour on our feet. Excessive sitting, more than two hours a day, is referred to as 'sitting disease' among health professionals, and is associated with some major -- and perhaps surprising -- health problems, as well as an overall shorter life expectancy.
It's Ruining Your Posture
Poor posture is a headache -- literally. And a shoulder ache. And a neck ache. And we can't overlook the back problems associated with a sedentary lifestyle. You might be sitting too much, and during all the time spent seated, you might be sitting the wrong way. Sitting improperly not only causes tight muscles and muscle pain, it also increases your risk of developing an inflexible spine and herniated lumbar disks, as well as conditions such as kyphosis, which is a rounded or hunched upper back, and lordosis, which is a swayback.
So if slouching and slumping don't meet the gold standard of sitting, what does? Good posture means your body is well-aligned, and well-aligned means your weight is evenly distributed, your shoulders are aligned over your hips, hips over knees -- you get the idea. It's pretty much the opposite of slumping over your desk.
When you sit more frequently than you exercise, your muscles weaken – and quickly. A sedentary lifestyle causes what's called disuse atrophy (that's opposed to muscle atrophy due to neurogenic causes, such as muscular dystrophy). Basically, that means when you don't use your muscles you lose your muscles. Muscle fibers lose their flexibility and become stiff, they lose bulk and mass, and they gain fat storage instead of turning those fats into muscle energy.
Additionally, when you're in a sitting position you're basically training your muscles to be better-suited for sitting. Your glutes and your leg muscles, for example, shorten compared to if you spent similar time standing -- and that means aches, pains and balance issues. Sitting weakens the muscles you use for posture and the abdominal, pelvic and spinal muscle groups, as well.
It Weakens Your Bones
As many as half of adult Americans are affected by bone loss. Ten million live with osteoporosis, and even more -- about 43 million more -- have lost enough bone mass that they're at a high risk of developing osteoporosis, according to the National Osteoporosis Foundation [source: NOF]. To strengthen your bones and prevent osteoporosis, you need to stand up. Bones need to support your weight -- or some weight -- regularly in order to stay strong; otherwise they lose their density and become brittle and weak.
Daily walking will help you make strides against osteoporosis, as well as both weight-bearing exercises and resistance training. Exercises that put a little pressure on those bones keep bone loss at bay (and it'll also build muscles and keep you flexible, too).
It Slows Your Metabolism
It doesn't take much time sitting around to slow down the process by which your body converts food into energy and regulates multiple biological processes. In the time it takes to watch just one episode of "Game of Thrones" (about an hour of sitting), your body slows down its production of the fat-burning enzyme lipase by 90 percent. When your metabolism slows down, if you don't also slow down your caloric intake and up your exercise you're going to gain weight. But you also lose, too -- your body loses the good cholesterol, HDL, that keeps the bad LDL cholesterol in check, putting you on a path toward cardiovascular disease. You'll also lose efficiency in how well your body is able to effectively manage insulin, steering you toward diabetes.
Underused Muscles, Underused Insulin
You may be inactive, but your pancreas didn't get the memo. The muscle inactivity that comes along with sitting disease has been associated with a decrease in your body's sensitivity to the insulin your pancreas makes, and that puts you at an increased risk of developing chronic diseases including metabolic syndrome (conditions associated with pre-diabetes) and type 2 diabetes (by about 7 percent) [source: University of Leicester]. Researchers are finding that women may be more at risk for this side effect of sitting than men.
Too much insulin in addition to higher levels of C-reactive protein and other chronic inflammation markers circulating in your sedentary body are also linked to certain cancers, such as breast and colon cancer (about a 10 percent risk increase) [source: Yates, et al]. It's theorized that when the body becomes less sensitive to insulin, levels build up in the body; the excess insulin in your body stimulates cell growth. It's also possible hours of sitting decreases production of antioxidants, which are the body's natural way of protecting itself against free radicals, known cell damagers (and cancer causers).
It Clogs Your Heart
Researchers have reported couch potatoes who spend more than four hours a day sitting passively in front of a screen have roughly a 125 percent greater risk of developing symptoms of cardiovascular disease, such as angina (shortness of breath) or experiencing a heart attack than their peers who only spend about two hours doing so [source: Levine].
Sitting is clogging your heart. Excessive sitting changes the way your body handles fats (known as lipids) in your blood, and the outcome isn't good. It puts the brakes on HDL production; HDL is known as the good cholesterol because it cleans up the bad cholesterol, LDL, which builds up on the walls of your arteries. Researchers have associated all that sitting you're doing with lower amounts of HDL circulating in your body, and that means lipids and triglycerides are allowed to build up -- and that fat in your blood puts you at a greater risk of developing cardiovascular disease [source: Berkowitz and Clark].
Poor Circulation in Your Lower Extremities
When you sit for more than an hour at a time, you increase your risk of developing peripheral edema -- that's swelling caused when fluid builds up in the tissues in your lower extremities (legs, ankles, and feet). The lack of circulation also ups your odds of developing or worsening varicose veins, suffering from thrombophlebitis, or suffering a blood clot, specifically deep vein thrombosis.
Poor blood flow doesn't just affect your lower extremities; it also can cause damage to other organs in your body as well as cause you to feel dizzy, numb or as though you're in a mental fog.
It Contributes to Sleep Apnea
More than 18 million Americans live with sleep apnea, a condition that causes pauses in your breathing as you sleep [source: AADSM]. If you're male, over 40 and are carrying a few too many extra pounds, you're at risk. You're also at greater risk of having the condition, or worsening it, if you spend too much time sitting. The problem? Poor circulation and fluid retention.
During the day as you sit, your lower extremities retain fluid -- you can thank gravity for that. When you're lying down at night, here's what's happening: The fluid that's built up in your legs can now move freely about, and as it moves to your neck and upper airway it narrows your windpipe.
It's Ruining Your Mood -- and Your Creativity
It's not just your body that's taking the brunt of the damage from all that sitting. When the body isn't working efficiently to circulate blood, oxygen and important hormones and chemicals as it should, your mind goes dull, and your mood and self-esteem take a nosedive.
In 2011 the Centers for Disease Control and Prevention (CDC) Take-a-Stand study found that employees who were able to stand while working reported they were in better moods and had higher self-esteem than when they sat all day. Eighty-seven percent reported feeling more energized and 71 percent reported they felt more focused, in addition to overall fewer complaints of fatigue, tension and depression [source: CDC, JustStand.org].
While additional studies have found slouching is associated with negative physiological changes, depressive moods and low energy levels, standing, it turns out, invigorates your body's processes, boosts your metabolism, strengthens muscles and bones and burns as many as 20 percent more calories compared to sitting [source: Savoie].
Every Hour of Sitting Increases Your Odds of a Disability
Watch out -- as we get older, sitting becomes a perilous activity. It sounds mad, risky sitting, but according to a 2013 study published in the Journal of Physical Activity & Health, it's true. Adults over age 60 average about nine hours of sitting each day, and what researchers found when they studied this age group is that for every additional hour spent sitting, the odds of that person developing an activities of daily living (ADL) disability increased by almost 50 percent. ADL includes things we normally take for granted, such as dressing ourselves, bathing and walking, and that risk of developing an ADL disability exists regardless of whether you're engaging in physical activity in addition to all those sedentary hours [source: Dunlop].
The cerebellum controls voluntary movements like posture, balance, coordination and speech. HowStuffWorks looks at this amazing part of the brain.
Author's Note: 10 Ways Sitting Wrecks Your Body
Don't take this sitting down. Ha! (I just couldn't help myself.) Jokes aside, there are some pretty frightening statistics associated with spending a lot of time seated, especially as many of them were stats on how likely you are to die prematurely depending on how many hours you sit each day (40 percent more likely if you sit more than 2 to 4 hours? Yikes!).
- How Death by Cubicle Works
- Why is sitting in a chair for long periods bad for your back?
- The Ultimate Causes of Back Pain Quiz
More Great Links
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- American College of Sports Medicine (ACSM). "Reducing Sedentary Behaviors: Sitting Less and Moving More." (June 27, 2014) http://www.acsm.org/docs/brochures/reducing-sedentary-behaviors-sitting-less-and-moving-more.pdf
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