Sit Less Now or Risk Not Walking Later

effects of prolonged sitting

Story at-a-glance -

  • Prolonged sitting promotes multiple challenging health conditions, including heart disease, type 2 diabetes, osteoarthritis, certain cancers and lower back pain
  • Recent research demonstrates that watching television for extended periods may increase your risk for reduced mobility as you age that may lead to a loss of independence
  • Consider using a fitness tracker to count your steps, standing while taking phone calls at work, requesting a standing desk at work, or walking after lunch to increase your movement and reduce your health risks

By Dr. Mercola

A large number of studies have demonstrated the health challenges you face when you sit for long hours each day. Inactivity promotes the development of Type 2 diabetes, heart disease and obesity, to name just a few chronic conditions associated with being sedentary. Unfortunately, a highly technological society does not, by its very nature, encourage a great deal of activity.

The average American working in an office easily sits between 12 to 15 hours each day.1 Even a strong workout in the morning cannot undo the damage to your body when you sit behind a desk for eight hours.2 To avoid much of the damage created from excessive sitting, it's important to sit less than three hours a day. I typically seek to sit under one hour a day.

A study analyzing data from 54 countries found sitting less increased life expectancy and sitting less than three hours each day was the optimal number to achieve.3 The lead author of the study acknowledges that despite a growing body of strong scientific evidence demonstrating the dangers of too much sitting, it's difficult for people to make changes.

Long commutes to and from work, labor-saving devices and a lack of support for active lifestyles contribute to this growing problem. In a recent study, scientists have now demonstrated how sitting for long periods of time is also an independent risk factor for poor mobility as you age.4

Sitting Increases Risk of Immobility as You Age

Studies support using a consistent exercise routine to help improve your metabolism, reduce your risk of diabetes and certain cancers, help you maintain a healthy weight and improve your cardiovascular health. Further research demonstrates that even when you engage in regular exercise, it may not be enough to offset the disadvantages to your health from too much sitting.5

Research led by Loretta DiPietro, Ph.D., department chair in exercise science at the Milken Institute School of Public Health, now finds that increasing inactivity as you age may also reduce your ability to get around and remain mobile. During the study, the researchers examined data from people age 50 to 71 across eight to 10 years from a large NIH–AARP diet and health study that started with all healthy participants, between 1995 and 1996.6

The researchers evaluated recordings of how much time people watched television, gardened, did housework, exercised or engaged in other physical activity during the study period.

The results were not too surprising as they found those who were most active, sitting less than six hours each day, were the least disabled and those who were least active, getting less than three hours of activity a week, were the most disabled.7 The researchers concluded8 that "reduction of sedentary time, combined with increased physical activity may be necessary to maintain function in older age."

Television May Be the Greater Risk

One piece of information revealed in the analysis of data was that "greater TV time was significantly related to increased disability within all levels of physical activity."9 After age 50, the results from the study suggest that prolonged sitting, especially in the evening hours in front of the television, is "particularly hazardous."10

DiPietro believes TV viewing may be specifically problematic as it is usually not broken up with short bouts of physical activity, as compared to sitting at your desk during the day. Where once you got up to change channels on the television, you now don't even need to sit through ads by streaming shows through Netflix or Hulu. DiPietro comments:11

"We've engineered physical activity out of our modern life with commuting, elevators, the internet, mobile phones and a lifestyle — think Netflix streaming — that often includes 14 hours of sitting per day … TV viewing is a very potent risk factor for disability in older age.

Sitting and watching TV for long periods — especially in the evening — has got to be one of the most dangerous things that older people can do because they are much more susceptible to the damages of physical inactivity."

The researchers found those who sat in front of their televisions for several hours in combination with less than three hours of physical activity each week experienced an acceleration of risk for harmful health effects. They also determined those who experienced any level of physical activity but also sat for increasing hours in front of a screen watching TV had an increased likelihood of a walking disability.

Sitting Long Hours Linked to a Host of Health Problems

The biological effects associated with prolonged sitting are an independent risk factor for other health conditions and early death as well. Today this is often called the "sitting disease," the result of sitting for prolonged periods in front of a computer screen, texting, commuting and shopping online.

You don't have to work too hard not to leave your home. You can order everything you need online, including groceries in most areas. Entertainment, communication and video chatting may mean you don't get out of your chair for hours at a time.

The health challenges resulting from sitting for prolonged periods are related to sedentary behavior, and while sitting is the most prevalent form of sedentary behavior, it isn't the only one. Any activity during which you exert very little energy is considered sedentary behavior. Although the scientific community has coined the term "sitting disease" to refer to metabolic syndrome and other ill effects of a sedentary life, the medical community does not use this as a diagnosis. The results of sitting prolonged periods may include:12,13,14,15,16

  • Death — In a study of over 123,000 people, researchers found women who sat for six hours or more each day had a 94 percent increased risk of death from all causes during the study period than women who sat for three hours or less. Men who were inactive and sat for six hours or more were 48 percent more likely to die than men who were more active.
  • Obesity — A study of 50,000 women over six years found every two-hour increase in viewing television a day resulted in a 23 percent jump in risk of obesity, and for every additional hour women spent sitting at work without getting up resulted in an additional 5 percent increased risk of obesity.
  • Metabolic syndrome — Absence of muscle contraction during extended periods of time reduces your ability to metabolize and process carbohydrates, leading to the chief risk factors for insulin resistance, Type 2 diabetes, heart disease and stroke.
  • Cancer — A meta-analysis of 47 studies found an increasing amount of inactivity or sedentary behavior resulted in a higher risk for cancer and an increased risk of death from their diagnosis.
  • Lower back pain — Sitting for long periods of time places added strain on your lower back, reduces your core strength and reduces circulation to the small muscles in your lower back, all leading to an increased risk of lower back pain.

Your Risk of Osteoarthritis Rises With Inactivity

The technological or digital revolution began in the early 1950s.17 In a recent study, researchers found those born after 1940 had a 2.5 times greater risk of developing osteoarthritis (OA) than those who were born before 1940.18 Osteoarthritis is one of the most common forms of nearly 100 medical conditions that fall under the category of arthritis.19 Some of the factors that increase your risk of developing OA include obesity, lack of activity, muscle weakness and increasing age.20

Even after controlling for age and body mass index, researchers found a significant rise in the number of people suffering from OA. According to researcher Ian Wallace, Ph.D., a research fellow in the Skeletal Biology and Biomechanics Lab at Harvard University's department of human evolutionary biology:21

"Although knee OA [osteoarthritis] prevalence has increased over time, today's high levels of the disease are not, as commonly assumed, simply an inevitable consequence of people living longer and more often having a high BMI. Instead, our analyses indicate the presence of additional independent risk factors that seem to be either unique to or amplified in the postindustrial era."

Although the study looked at the difference in numbers of individuals who suffered from OA over thousands of years, the researchers could only theorize what the lifestyle differences were that created such variability. They speculate that one of the primary factors is inactivity. Senior study author Daniel Lieberman, Ph.D., paleoanthropologist at Harvard University, posits inactivity may play a leading role in the development of OA, saying:22

"The most important message here is that we shouldn't consider arthritis a wear-and-tear disease of age. Arthritis is a disease that becomes more common as you age, but it's not caused by 'wear and tear;' if anything, it might be caused by the absence of physical activity."

With Loss of Mobility May Come Loss of Independence

Senior citizens who face issues with loss of mobility may also grapple with a loss of independence, resulting in psychological and social challenges. Individuals who lose their ability to live on their own may experience an inability to socialize with their friends, an increasing sense of loss, growing depression and anger.23,24

Seniors who lose their independence may also experience a loss of cognitive function. Researchers followed over 5,500 people living in the community who were over age 65 in the first prospective study that demonstrated a progressive cognitive decline associated with a specific pattern of functional ability.

In another commissioned study, researchers found that seniors feared entering a nursing home and losing their independence more than they feared death.25 Although 83 percent of those in the study desired to stay home as they aged, over 50 percent were afraid they wouldn't be able to. Interventions developed by NIH-supported Claude D. Pepper Older Americans Independent Centers are based on preventing falls and improving muscle function using simple weight training and mobility to improve independence.26

Simple Strategy May Improve Your Physical Ability as You Age

You may be surprised at how many hours you sit each day, especially if you participate in daily exercise. Take a few minutes for three to four days to record the amount of time you exercise, sit or stand. This will help to give you an indication of your risk factor for developing OA, metabolic syndrome or losing your independence. One simple strategy to reduce your risk is to move more, every day. However, while simple, it can be challenging to accomplish. Here are several tactics you may consider:

Set up an alarm on your computer to remind you to get up every 15 minutes. Ask your employer about using a standing desk at work.
Stand while talking on the phone or eating lunch. Walk after lunch; develop a walking group at work to help your motivation.
Use a fitness tracker to count your steps each day and seek to achieve 10,000 steps. Watch TV on a Swiss ball and bounce while watching.
Work with an accountability partner who you can share your challenges and successes with. Walk laps around a conference table with your colleagues during meetings.