Science of Sedentary Behavior

Reducing sitting in the workplace may help drive lower obesity rates and better health

The emerging field of “inactivity physiology” suggests that the hours people spend sitting – time spent on email, sitting in meetings, using the Internet, wrestling with and writing computer applications, sitting in traffic – may be linked to increasing rates of obesity and chronic disease.

The key may be in the function of muscles in the legs, back and neck that help maintain posture during standing and light exercise. These postural muscles seem to have a larger role in the processing of fat and cholesterol than was previously understood. As a result, people who sit for a long time without getting up and exercising these postural muscles may experience health problems – despite getting regular exercise during other parts of the day. This hypothesis has been pieced together from sources as varied as animal testing, measurements of TV viewing, bed-rest studies and zero-gravity experiments by NASA.

“Lack of physical activity is not the same as ‘too much’ sitting,” said Neville Owen PhD, professor of health behavior at the University of Queensland in Australia. “ We used to think that just exercising was the answer. Exercising is still very important, but in addition, we are learning that too much sitting may be in itself a problem . ”

To explore these issues and identify areas and techniques for additional research, the Stanford Center on Longevity and Stanford Prevention Research Center convened medical, behavioral, ergonomic and technology experts from both academia and industry on the Stanford campus on July 15-16, 2010.

At the root of the conference was research that considers physical activity from a different perspective: exploring whether prolonged sitting – even for people who exercise – creates health risks. For example, the first findings using self-reported measures of television-viewing time and overall sitting time have recently been confirmed using objective measurement (accelerometers) of physical activity and sedentary time. Studies of bed rest and the biological consequences of zero-gravity environments also provide important clues about mechanisms through which prolonged sitting may exert its deleterious health consequences. Researchers discussed how current data on the health risks of sedentary behavior is compelling, but not currently conclusive enough to support new public health guidelines.

“We are trying to set the research agenda for the next five years,” said William Haskell PhD, director of the Stanford Prevention Research Center and professor of medicine.

The range of expertise represented at the conference enabled participants to implement something unique. Academic researchers and physicians outlined the types of studies that are needed to make conclusive determinations. Discussions with industry participants will help inform large-scale studies in controlled environments that can help outline new guidelines for healthy workplaces. Technical experts helped identify innovative and conventional devices that can measure sedentary behavior and sure high-quality results for studies. A selection of exercise balls, standing tables, and a culture that encouraged pacing during presentations demonstrated simple techniques for avoiding prolonged sitting.

“Bringing together the top minds – from eminent researchers to experts on the workplaces – provides us with an opportunity to decrease high rates of sedentary behavior, obesity and related chronic diseases and enable people to live happier, healthier, longer lives,” said Ken Smith, director of academic and research support at the Center on Longevity.


Standing room only at Stanford sitting risks event
The Associated Press, July 15, 2010