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  • Sitting for more than eight hours a day is associated with a 90 percent increased risk of type 2 diabetes
  • Those who sit the most have a 147 percent increased relative risk of cardiovascular events compared to those who sit the least; all-cause mortality is increased by 50 percent
  • Sitting also increases lung cancer 54 percent; uterine cancer by 66 percent, and colon cancer by 30 percent
 

Even if You Exercise, Sitting Eight Hours a Day Significantly Increases Your Risk of Dying From Any Cause

February 06, 2015 | 336,863 views
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By Dr. Mercola

If you’re like most people, you spend a vast majority of your day sitting down—in your office, commuting to and from work, watching TV in the evening... Research1 shows that the average American spends nine to 10 hours of their day sitting.

Certain occupations, such as telecommunications employees spend an average of 12 hours sitting each day. I was certainly in that group and for 15 years was sitting more than 12 hours a day. And, the more sedentary you are at work, the more sedentary you will tend to be at home as well.

Thankfully, last year, the evidence became overwhelmingly compelling and I have essentially eliminated 95 percent of my sitting. I found that merely getting up for a few minutes even six times an hour would not help eliminate my back pain but stopping sitting altogether did.

Even on weekends, the average person sits for eight hours. This behavior can be more problematic than you might think, as the human body was designed to be in more or less constant movement throughout the day.

I really wasn’t  aware of this prior to last year, but the evidence shows that prolonged sitting actively promotes dozens of chronic diseases, including overweight and type 2 diabetes, even if you’re very fit. This is really highly counterintuitive as it would seem physically fit people could get away with sitting.  

However, research shows that maintaining a regular fitness regimen cannot counteract the accumulated ill effects of sitting eight to 12 hours a day in between bouts of exercise. This is very strong evidence to seriously consider eliminating as much sitting as you can.

Sitting really is the new smoking and it increases your rate of lung cancer by over 50 percent. Who would have known that sitting is far more dangerous than second hand smoke?

Analysis Concludes: Sitting Kills, Even if You Exercise

There’s really compelling evidence showing that when you sit for lengths of time, disease processes set in that independently raise your mortality risk, even if you eat right, exercise regularly and are very fit; even a professional or Olympic level athlete.

The most recent systematic review2,3 looked at 47 studies of sedentary behavior, and discovered that the time a person spends sitting each day produces detrimental effects that outweigh the benefits reaped from exercise.

Sitting was found to increase your risk of death from virtually all health problems, from type 2 diabetes and cardiovascular disease to cancer and all-cause mortality. For example, sitting for more than eight hours a day was associated with a 90 percent increased risk of type 2 diabetes.

Other research4 has found that those who sit the most have a 112 percent increased Relative Risk of diabetes, and a 147 percent increased relative risk of cardiovascular events compared to those who sit the least.

All-cause mortality is also increased by 50 percent. In fact, chronic sitting has a mortality rate similar to smoking.5 And, the less you exercise, the more pronounced the detrimental effects of sitting. To counteract the ill effects of prolonged sitting, the authors of the featured review6 suggest that you:

  • Keep track of how much you’re sitting each day, and make an effort to reduce it, little by little, each week
  • Use a standing desk at work. Although standing up frequently is better than constant sitting I am now strongly convinced that avoiding sitting completely is far preferable and has better metabolic effects.
  • When watching TV, stand up and/or walk around during commercial breaks

More Studies Highlighting Debilitating Effects of Sitting

Part one in a two-part series of articles7 published in the British Medical Journal (BMJ) at the beginning of January also highlights the hazards of our modern sedentary lifestyle, suggesting that public policy needs to be reassessed and updated to focus on increasing movement during work hours.

The article summarizes the findings from the 2015 Inaugural Active Working Summit, where a number of health effects of sitting were reviewed, including cancer and mental health. For example, one study presented at the summit found that sitting increases:

  • Lung cancer by 54 percent
  • Uterine cancer by  66 percent, and
  • Colon cancer by 30 percent

The reason for this increased cancer risk is thought to be linked to weight gain and associated biochemical changes, such as alterations in hormones, metabolic dysfunction, leptin dysfunction, and inflammation—all of which promote cancer. Research also shows that your risk for anxiety and depression rises right along with hours spent in your chair.

Why Sitting Causes So Much Harm


Download Interview Transcript

Dr. James Levine, co-director of the Mayo Clinic and the 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 show that when you’ve been sitting for a long period of time and then get up, a number of molecular cascades occur. For example, within 90 seconds of standing up, the muscular and cellular systems that process blood sugar, triglycerides, and cholesterol—which are mediated by insulin—are activated. 

All of these molecular effects are activated simply by carrying your own bodyweight. These cellular mechanisms are also responsible for pushing fuel into your cells and, if done regularly, will radically decrease your risk of diabetes and obesity. In short, at the molecular level, your body was designed to be active and on the move all day long. When you stop moving for extended periods of time, it’s like telling your body it’s time to shut down and prepare for death... As noted by Dr. Levine, while we clearly need to rest from time to time, that rest is supposed to break up activity—not the other way around! Inactivity—sitting—is not supposed to be a way of life.

[T]his very unnatural [sitting] posture is not only bad for your back, your wrists, your arms, and your metabolism, but it actually switches off the fundamental fueling systems that integrate what’s going on in the bloodstream with what goes on in the muscles and in the tissues,” he says.

As a consequence of sitting, your blood sugar levels, blood pressure, cholesterol, and toxic buildup all rise. The solution to these adverse events do not involve a prescription—all you need to do is get up, and avoid sitting down as much as possible. If you’ve been sitting down for a full hour, you’ve sat too long, and the cellular mechanisms involved in the maintenance of your body and health are shutting down. We are in the process of providing all our employees at mercola.com standing desk options. If you have a sit down job I would strongly encourage you to present this information to your employer and get a stand up desk.

Avoiding Sitting is the First Step Toward a Healthier Lifestyle

The World Health Organization (WHO) recommends getting at least 150 minutes of physical activity per week, but researchers say this may be too ambitious a goal for many people—particularly the elderly, at least to start. They suggest a more realistic approach may be to simply avoid sitting still as much as possible.  In a paper8 titled, “Recommendations for Physical Activity in Older Adults", Professor Phillip Sparling and colleagues write:

“There is now a clear need to reduce prolonged sitting. Secondly, evidence on the potential of high intensity interval training in managing the same chronic diseases, as well as reducing indices of cardiometabolic risk in healthy adults, has emerged. This vigorous training typically comprises multiple 3-4 minute bouts of high intensity exercise interspersed with several minutes of low intensity recovery, three times a week.

Between these two extremes of the activity spectrum is the mainstream public health recommendation for aerobic exercise... 150 minutes a week of moderate intensity activity in bouts of 10 minutes or more... However, many people, especially in older age groups, find it hard to achieve this level of activity. We argue that when advising patients on exercise doctors should encourage people to increase their level of activity by small amounts rather than focus on the recommended levels. The 150 minute target, although warranted, may overshadow other less concrete elements of guidelines. These include finding ways to do more lower intensity lifestyle activity...”

A Fitness Tracker Can Be a Helpful Tool

Part of the solution may also be to reassess your use of technology. Your TV, for example, can increase your sedentary time by hours each day, so consider trading some of that sedentary time for something more active. That doesn’t mean that all technology is detrimental though.9 I’m very excited about the explosion of wearable fitness trackers for example, which can measure your activity levels and track how long and how well you sleep. It’s hard to change a habit if you’re not tracking it, and devices like these can help you modify your behavior over time, such as motivating you to walk more, and get in bed earlier to get your eight hours of sleep.

If you don't already have a fitness tracker, I would encourage you to get one. Jawbone’s Up3,10 when it is released later this year, will be among the most advanced fitness trackers to date, but even more advanced ones are sure to follow. The Apple Watch,11 which is also set to launch this year is one example. I have reviewed many of them and Jawbone is one of the best, featuring a suite of state-of-the art sensors that provide a wide array of health data. I recommend aiming for 7,000 to 10,000 steps per day, over and above any exercise regimen you may have, and to shoot for eight hours of sleep each night. With a fitness tracker, you can track all of this and more. I was probably doing 2,000 steps a day prior to using one and now I am up to about 15,000 steps a day or about eight miles. I am able to read my Kindle while walking and have been able to read a book a week.

When Sitting Is Unavoidable, Keep Posture in Mind

While it’s certainly possible to limit sitting, it’s still an unavoidable part of most people’s lives. The question then becomes, how can you limit the risks associated with sitting? Paying attention to your posture is one way. A recent CNN article12 suggests “sitting smarter” by incorporating yoga postures and being aware of your breathing, and presents a five-point yoga-based posture check that can make for healthier sitting.

Also familiarize yourself with your body’s signals to shift or move. Following the recommendations by “posture guru” Esther Gokhale may also go a long way toward improving posture-related pain associated with prolonged sitting, and will likely help ameliorate the worst risks of sitting. The basics of healthy sitting include the following points:

  • Stack sitting: In order to allow the bones in your spine to stack well and permit the muscles alongside them to relax, sit with your behind sticking out behind you, but not exaggeratedly so. Now, when you breathe, each in-and-out breath will automatically lengthen and settle your spine. This gentle movement stimulates circulation and allows natural healing to go on even while you sit.
  • While conventional advice tells you to tuck in your pelvis to maintain an S-shaped spine, Esther has found that a J-spine is far more natural. A J-spine refers to a posture where your back is straight, your lumbar relatively flat, and your buttocks are protruding slightly. By tucking your pelvis, you lose about a third of the volume in your pelvic cavity, which squishes your internal organs. This can compromise any number of them in a variety of ways. This is further compounded if you’re both “tucked” and “hunched” while sitting.

  • Stretch sitting. Another way to elongate your spine is by using your back rest as a traction device. You can see her demonstrate this move in the video below. You will need either a towel or a specially designed traction cushion for this purpose. This simple maneuver brings your back away from the back rest, lengthens your spine, and then roots you higher up against the back rest.
  • This position helps you maintain an elongated spine, and by getting traction on your discs, you allow them to rehydrate and prevent the nerves from being impinged between your vertebrae. It will also help flatten out your lumbar area, and this alone can sometimes provide immediate pain relief if you have sciatic nerve root pain. Although please remember that sitting should be your last resort when you have no alternative. It is far better for you to stand than sit. It might take a bit to adjust but once you do it will be every bit as comfortable as sitting.

Make Walking a Part of Your Daily Routine

The evidence is overwhelming at this point—10,000 studies and growing—that prolonged sitting will reduce your lifespan by promoting dozens of chronic diseases, even if you exercise regularly. I’ve previously recommended standing up and doing exercises at your desk every 10-15 minutes to counteract the ill effects of sitting, but after reading Dr. Levine’s book, I’m convinced even that may be insufficient if you’re seeking optimal health. I really think the answer is to stand up as much as possible.

That said, I realize some people may be limited by work policies and/or other factors, and eliminating sitting altogether is too lofty a goal. I’m simply suggesting you take a closer look at how you spend your day, and find ways to stand up or move more often. For a number of tips and tricks, please see my previous article, "Tips for Staying Active in the Office." Remember, as a general rule, if you’ve been sitting for one hour, you’ve sat too long. At bare minimum, avoid sitting for more than 50 minutes out of every hour.

I believe high intensity training, non-exercise activities like walking 7,000 to 10,000 steps a day, and avoiding sitting whenever possible is an ideal combination for optimizing your health. And, while I recommend walking in addition to your regular fitness regimen, not as a replacement for it, if you’re currently doing nothing in terms of regimented exercise, walking is certainly a great place to start. For many, simply getting and staying out of your chair is a first step that can bring you closer to a healthier lifestyle. As you become more used to low level, non-exercise activity, you’re more likely to get motivated enough to start exercising more vigorously.