Source: Mercola.com
Story at-a-glance
- Over 300 joints in your body make moving easier and more fluid, but the rising tide of technology has increased the number of hours people spend sitting each day
- You can’t out-exercise the number of hours you sit at work, in the car and in front of the television, which increases your potential risk for heart disease, diabetes, obesity and cancer
- Data indicates moving as little as 10 minutes for every hour of sitting may help reduce negative effects; ideally you should be sitting no more than three hours each day using correct posture to reduce strain on your lower back and neck
- Take a simple sitting-rising test to find your fitness and balance levels and create a movement-rich environment through strategies such as getting up to drink every hour, moving frequently used items away from your desk, and using an exercise ball chair
By Dr. Mercola
With over 300 joints, your body was made for movement. Although the rising tide of technology has created an amazing number of ways to share information, it has also increased the number of hours you remain seated each day. It's likely by now most understand sitting glued to your desk all day increases your risk of illness and early death.
Unfortunately, the average U.S. adult spends nine to 12 hours each day sitting,1,2 and a 60-minute workout cannot counteract the effects of this level of inactivity.3 Sitting is not inherently dangerous. The danger is in the amount of time you spend sitting. Brief periods of sitting are natural, whereas long periods can seriously impact your health and shorten your life.
Exercise Likely Not Enough to Offset Damage Done by Sitting All Day
A recent study in the Annals of Internal Medicine4 demonstrated that sitting for prolonged periods of time can indeed be deadly. Even those who exercised heavily when they were not at the office experienced a significantly increased risk of death when seated for eight hours a day.
During the study, the team evaluated 8,000 Americans over the age of 45 for a four-year period. Participants wore accelerometers to track their movements. The researchers found those who moved more were healthier overall. However, they also found a correlation between death rates of participants and how many hours they spent seated during the day. In other words, there was a relationship between the time spent seated and the risk of early mortality from any cause.5
Although the American Heart Association encourages sitting less and moving more, the guideline maybe too simplistic. Keith Diaz, certified exercise physiologist and lead author of the study at Columbia University, believes this is like telling someone to exercise without telling them how.6
Instead, guidelines should be precise, such as those by the U.S. Centers for Disease Control and Prevention, which recommends moderate-intensity aerobic exercise for 2.5 hours every week, plus strengthening activities two or more times a week. Diaz says:7 “We need similar guidelines for sitting. We think a more specific guideline could read something like, ‘For every 30 consecutive minutes of sitting, stand up and move or walk for five minutes at a brisk pace to reduce the health risks from sitting.’”
Although previous studies found daily sitting time to average between nine and 10 hours per day,8 data analysis from this study found an average of 12.3 hours of sedentary behavior for an average 16-hour waking day.
As total sedentary time increased, so did early death by any cause, regardless of the participants’ age, sex, race, body mass index or exercise habits.9 The results indicated those who sat in stretches of less than 30 minutes had a 55 percent lower risk of death than those who sat for more than 30 minutes at a stretch.
What Happens When You Sit for Long Periods of Time?
Sitting for long periods of time takes a toll on your body. Dr. James Levine, codirector of the Mayo Clinic/Arizona State University Obesity Initiative, and author of the book “Get Up! Why Your Chair Is Killing You and What You Can Do About It,” has dedicated a good part of his career to investigating the health effects of sitting.
His investigations demonstrate when you sit for long periods of time a number of molecular cascades are initiated. Ninety seconds after standing, muscular and cellular systems processing blood sugar, triglycerides and cholesterol are activated, simply by carrying your own body weight.
These cellular mechanisms are also responsible for pushing fuel into your cells, and when done regularly, may radically reduce your risk of diabetes and obesity. In other words, while your joints make movement easier, your body enjoys benefits even at the molecular level.
Although many recommend standing for 10 minutes of every hour of sitting, I believe this is the bare minimum and far from ideal. It seems far wiser to strive to sit as little as possible each day. Here are some things that may go wrong when you're parked in front of your desk all day long.10
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Heart In the seated position, muscles burn less fat and blood flows more sluggishly. Prolonged sitting has been linked to hypertension, and research data demonstrates women who sit for 10 hours a day may have a significantly greater risk of developing heart disease than those who sit for five hours or less.11 |
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Pancreas Research has demonstrated those who sit for long periods of time are twice as likely to have diabetes or heart disease, compared to those who sit the least.12 Sitting eight hours a day has been associated with a 90 percent increased risk of Type 2 diabetes.13 |
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Cancer Sitting may increase your risk of colon, breast, lung,14 uterine and endometrial cancers. This increased risk may be due to an excess insulin production encouraging cell growth, or a reduction in protection from antioxidants regular movement boosts in your body. Another risk may be related to weight gain and associated biochemical changes, such as alterations in hormones, metabolic dysfunction, leptin dysfunction and inflammation. |
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Digestion Sitting after eating slows digestion and compresses your abdominal contents. This in turn may lead to cramping, bloating, heartburn and constipation, as well as dysbiosis in your gastrointestinal tract. This is a condition created by microbial imbalances. According to Microbial Ecology in Health and Disease,15there's growing evidence it is associated with pathogenesis of intestinal and extra-intestinal disorders, including inflammatory bowel disease, irritable bowel syndrome and celiac disease, as well as allergies, metabolic syndrome, cardiovascular disease and obesity. |
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Brain Your brain function slows when your body is sedentary for too long. Your brain will get less fresh blood and oxygen, which are needed to trigger the release of brain- and mood-enhancing chemicals. |
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Posture Many commonly sit with head and neck forward working at a computer or cradling a phone. This leads to strain of your cervical vertebra, with permanent imbalances, which can lead to neck strain, sore shoulders and back. Sitting also increases pressure on your spine and the toll is worse if you are sitting hunched over. It is estimated 40 percent of people with back pain have spent long hours at their computer each day. |
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Muscles Standing requires your core muscles to be engaged, which often go unused when you sit in a slouched position. Your hips may also suffer, becoming tight with limited range of motion as they are rarely extended. This may lead to decreased mobility and falls in the elderly. Sitting weakens your gluteal muscles, affecting your stability and the power of your stride. |
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Legs Sitting leads to poor circulation in your legs, causing swelling in your ankles, varicose veins and blood clots known as deep vein thrombosis. Walking, running and engaging in other weight-bearing activities increases your bone density and reduces your risk for osteoporosis and bone fractures. |
Sitting Right Requires Greater Muscle Activation and Reduces Pain and Strain
When you do sit, it’s important to sit with good posture. This will help reduce problems with lower back pain, wrist strain and other physical challenges associated with poor posture. However, while using good sitting posture is important, it does not negate your need for more movement. When sitting in a correct posture you:16
- Sit with your back straight and your shoulders back, pulling your shoulder blades down. Your buttocks should touch the back of your chair and your head should remain upright, all of which engage your core muscles. Distribute your body weight evenly over both hips, with your knees bent at right angles, your feet flat to the floor. Do not cross your knees. Avoid twisting at the waist while sitting, but instead turn your whole body.
- Place your computer screen at a height allowing your head to remain level. This may mean getting an external keyboard to allow the keyboard at hand level and the screen at eye level.
- Avoid sitting for more than 20 minutes. Get up, walk, stretch or walk briskly for several minutes. This not only helps to reduce the effects of sitting, but it increases your blood flow and improves your creativity.
- When standing from the sitting position, move to the front of your seat and then stand up by straightening your legs. Avoid bending forward at your waist as this places additional pressure on your lower back.
- Consider a lumbar roll or back support while driving. Your knees should be at the same level or slightly higher than your hips. Move the seat as close to the steering wheel as necessary to support the curve of your back while keeping your elbows bent and your feet easily reaching the pedals.
Create a Movement-Rich Environment
Foundation exercises, developed by chiropractor Dr. Eric Goodman, can help counteract some of the damage caused by sitting. These exercises are used by many professional and elite athletes but, more importantly, they address the root cause of lower back pain related to weakness and imbalance along your posterior chain of muscles.
This short video demonstrates “The Founder,” a key exercise that helps reinforce proper movement while strengthening the entire back of your body. There are a significant number of benefits to standing during the day, including a slight rise in heart rate, calorie expenditure and greater insulin sensitivity.17
In addition to reducing your risk for the health conditions listed above, an increase in movement may add years to your life. Reducing the time you spend sitting down each day to three hours or less could increase your life expectancy by two years.18 Each hour watching television after age 25 reduces your life expectancy by nearly 22 minutes.19
Standing and moving also help improve weight management and productivity. There are several ways to accomplish this at home and at work requiring just a little creativity. Levine suggests walk-and-talk meetings when company administration agrees.
You may also consider moving objects you commonly use out of reach so you're required to get up if you need to throw something away or grab something off the printer. Make a habit of drinking 4 to 6 ounces of water every hour and place your container of pure, clean water from home in the refrigerator. This way you'll have to get up to fill your glass and will likely get up to use the bathroom on a more frequent basis.
Some companies are moving toward allowing employees to use standing desks or treadmill desks. Rather than sitting all day, you have the option of getting up and down. Keep in mind it may take a couple of weeks to build the stamina to stand for several hours during the day. If your employer is not open to a standing desk, consider standing at your desk when speaking on the phone or when you otherwise do not need your keyboard.
Ask your employer to consider an exercise ball chair. These are chairs with an open seat bottom where a Swiss exercise ball can be lodged. This provides you with an unstable platform on which to sit and increases your core muscle engagement while sitting.
Although this next option does not offer additional weight bearing and does not take the place of getting out of your chair, consider using a seated pedal exerciser. This is an under-the-desk apparatus that looks like the pedals on a bicycle and allows you to keep your legs moving while seated. If used, it's important your chair is placed high enough to ensure proper posture while seated.
The Simple Sitting-Rising Test You Can Do at Home Predicts Mortality
The ability to sit and rise from the floor may be able to predict your longevity over the next six years. Brazilian researchers20 developed a test different from the long-used chair test, in which physicians gauge an elderly person's lower body strength by how well they can stand up from a chair.
This new sitting-rising test is scored zero to 5 for each movement (sitting and rising), with a combined score of 10 being the highest and awarded only to those who can sit and rise from the floor without any assistance from their hands or knees. The test is very simple: You sit on and get up from the floor using as little assistance from your hands, knees or other body parts as possible. For each body part you use for support, you lose 1 point from the possible top score of 10.
For instance, if you put one hand on the floor to support yourself as you sit down and then use a knee and a hand to help as you get up, you lose 3 points for a combined score of 7. The scores correlated strongly with mortality during the six year study. For each increase in score, the participants gained a 21 percent improvement in survival. Specifically:
- Those who scored between zero and 3 were 6.5 times more likely to die during the study than those who scored between 8 and 10
- Those who scored 3.5 to 5.5 were 3.8 times more likely to die
- Those who scored 6 to 7.5 were 1.8 times more likely to die
I would not take the results of this study as “gospel.” However, if you are 30 years old and you score 3, it provides a perspective on the connection between mobility and health, and may encourage you to get back in shape. Even if you've been exercising like I have for five decades, it can still be a challenge.
The test is a simple measure of fitness at the most basic level, testing not only strength but also flexibility, balance and coordination. All of these are essential for day-to-day living and maintaining your independence as you age. Unfortunately, despite a growing body of research clearly demonstrating exercise deficiency threatens your overall health and mental well-being, only 15 percent of adults engage in vigorous physical activity three times a week for 20 minutes.21
Balanced Movement Reduces Injury
To read more about how sitting affects your biomechanics, movement and using soft-tissue work to down-regulate your body into recovery mode, see “Improving Your Health by Ditching Desks and Chairs.” The article also contains a 30-minute interview with Kelly Starrett, who has a Ph.D. in physical therapy and has focused his career on fitness and mobility.
I highly recommend Starrett’s book, “Deskbound: Standing Up to a Sitting World.” I believe most people can benefit from his wisdom and strategies to help address movement challenges. If you have a desk job, this book is a veritable gold mine of helpful guidance. Starrett is one of the leaders in the CrossFit movement and stresses the importance of proper body mechanics, both in and outside the gym. He also has a YouTube channel called MobilityWOD, which stands for Workout of the Day.
The interventions he suggests are not only powerful, they're also inexpensive — in most cases free. When you consider the well-documented benefits of movement over sitting, implementing these strategies is really one of the best types of health insurance you can get.
