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.