The Ill Effects of Prolonged Sitting

by Ram

Paul Writing by Camille Pissarro

We live in a hyper-competitive world, where most of us work at stressful, sedentary jobs. In fact, nearly 86 percent of American workers sit all day at their jobs. Furthermore, accumulating evidence suggests that we spend a majority of our time sitting and indulging in sedentary activities. Sedentary activities includes the time spent sitting in an automotive on a long commute, sitting at a desk at work, sitting on the couch after work, watching television, reading, and playing games or surfing the internet. Recent research indicates that on an average, an American adult spends 10-12 hours each day sitting. Notice that sitting is now the norm and physical exercise is considered an intervention program advised by your personal physician to nullify the negative impacts on your health.

Prolonged sitting time considered as one of the major instance of sedentary behavior has emerged as a strong risk factor for various negative health outcomes. Study results have demonstrated associations of prolonged sitting time with premature mortality, chronic diseases such as cardiovascular disease, diabetes, and cancer, metabolic syndrome, and obesity. Those who spend a lot of time sitting have an almost eight-fold increased risk of dying prematurely compared to those who exercise often and are hardly sedentary. Medical experts agree that one of the reasons for a high rate of obesity, high blood pressure, diabetes, cancer, depression and other health issues seen predominantly in younger age individuals is due to prolonged sitting and physical inactivity. For people who engage in prolonged sitting activities, their risk of heart attack is about the same as smoking. The negative consequences are so alarming that medical experts have started referring to the poor health outcome from prolonged sitting as “sitting disease”. 

The ill effects from prolonged sitting are not restricted to the US population alone. In a recent study All-Cause Mortality Attributable to Sitting Time: Analysis of 54 Countries Worldwide in the American Journal of Preventive Medicine, researchers used survey data from 54 countries, analyzing the time spent sitting more than three hours a day along with data on population size, actuarial tables, and overall deaths. More than 60 percent of people worldwide spend more than three hours a day sitting down, and the researchers calculated that sitting time contributed to some 433,000 deaths a year (nearly 3.8% of all-cause mortality) among those 54 countries. 

The above findings agree with another survey of some 220,000 Australian adults Sitting time and all-cause mortality risk in 222 497 Australian adults that was published in the Archives of Internal Medicine. Those who sat for more than eight hours a day had a 15 percent greater risk of dying within three years than those who sat for fewer than four hours a day. The results were more alarming for those who sat for 11 hours or more a day; they had a 40 percent greater risk of early death compared to those who sat for under four hours. This risk sustained even for those who spent some time exercising. Experts now are of the unanimous opinion that even 30 minutes of physical activity is insufficient to neutralize the detrimental effects of 8 hours or more of sitting.

You may wonder why prolonged sitting contributes to negative health outcomes. There are evolutionary and biochemical reasons for this. As humans, our body was simply not designed to sit for prolonged hours. We were evolutionarily designed to "work out,” as evident from our ancestral hunter-gatherers. Hence our body reacts negatively to prolonged sitting. At the cellular level, numerous changes happen all of which trigger the detrimental effects. Prolonged sitting:

• decreases the activity and levels of an enzyme that helps burn fat
• reduces bone mineral density and blocks new bone formation
• reduces the diameter of arteries putting the individual at risk for heart disease
• makes the body insensitive to insulin thus resulting in type-2 diabetes

Additionally, prolonged sitting affects the architecture of the spine, hips and neck as well putting the individual at risk for skeletal fractures. Furthermore, a recent study Television Viewing and Time Spent Sedentary in Relation to Cancer Risk: A Meta-Analysis found that prolonged sitting whether at work or home increases the risk of three cancers namely colon, endometrial and lung. The study also found that high participation in sedentary activities and low participation in physical activities was linked with a 41 percent higher risk of recurrence of colorectal adenomas.

For many of us sitting for eight hours a day at our job is inevitable. This compounded with the extra sitting outside of work is what makes it harmful. Besides, too much sitting is harmful even if you're getting enough exercise. This means you could be meeting the recommended guidelines for a daily exercise but you will still be at higher risk of disease if you sit for long periods each day. So how can one avoid the dreaded effects that come from prolonged sitting? The best solution is to drastically change your lifestyle. While standing for long hours by no means is the answer, most experts recommend a 50:50 sit-stand allowance for optimal health. If your occupation involves sitting for long periods, work at a standing desk. The potential benefits from a standing desk are manifold including: higher productivity, reduced absenteeism, and lower health care costs among many (see A Neutral Posture White Paper). Experts also agree that it is beneficial to interrupt sitting time as often as possible. One way to do this is to move or stretch for at least 10 minutes for every hour of sitting time. 

For those of us who have an active yoga practice, you can either bring in a mini office yoga series (Featured Sequence: Mini Office Yoga Practice) or supplemental yoga with you (Yoga, Your Companion Through the Day). If you need to stretch your back and do not have too much time at hand, you could think of the mini series for the back (Featured Sequence: Low Back Care). Since prolonged sitting is not only having an impact on public health but also has effects on the health span of the individual, it is never too late to make simple changes and maintain a reasonable amount of activity particularly across the middle and later years to avoid early death and serious illness. 

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