Blog: Sedentary Behavior - How Sitting Is Killing Us

Caitlin DeClercq

Core Researcher

                               Victor Villalobos

Graduate Student Researcher

Sedentary Behavior - How Sitting Is Killing Us

June 29, 2018

Revised July 12, 2018 

A library on campus recently advertised their new standing-height workstations with a catchy sign proclaiming that “sitting is the new sugar.” Like sugar, sitting may not be bad for your health in small doses, but too much can be a bad thing. The sentiment this example conveys points to a burgeoning literature linking prolonged sitting to a range of deleterious health outcomes and the need to promote movement and change in posture. In fact, recent studies have linked prolonged total sedentary time with obesity, diabetes, cancer, back pain, and psychological distress. Simply put, sedentary behaviors might be killing us. What can we do? First, let’s define sedentary behavior and then we’ll introduce some findings from our research.  

What is Sedentary Behavior?

Derived from the Latin sedens, meaning “to sit,” the word sedentary can mean either insufficient physical activity or excessive sitting. Yet to conflate these two ideas is to overlook the unique consequences each poses to human health.  An estimated two-thirds of adults fail to obtain adequate exercise, so physical inactivity is a health risk that pertains to a large portion of the American population. But even if we met physical activity guidelines, the benefits of such exercise could be “undone” if the rest of our waking hours are spent sitting down (Hamilton et al., 2008).  Good health depends on limiting sedentary time as well.

Sedentary behavior is generally defined as energy expenditure less than or equal to 1.5 metabolic equivalents while in a sitting, reclining, or lying posture.  By this definition, almost any seated activity, including computer work, watching TV, or even riding in a car, is considered sedentary behavior. The average person spends upwards of 8-10 hours sitting each day--likely more than they spend sleeping.  Why do we sit so much? Neville Owen suggests that sedentary behaviors are likely “determined more strongly by the situations people are in than by their individual characteristics” (Owen, 2017; see also Mullane et al., 2017). Indeed, routines and habits depend more on the context than do single, unique behaviors.  Therefore, the workplace context might play a key role to reduce sitting.

What Can We Do?

Each hour of daily sitting has significant implications for health.  One study estimated that for every additional hour of TV a person watched (a proxy for sedentary time), the risk of all-cause mortality increased by 11% (Dunstan et al., 2010).  Another study found that punctuating long periods of seated time with brief periods of standing, stretching, or moving reverses some of the deleterious impacts of sedentary behavior (Healy et al., 2008).  Thus, finding ways to interrupt or limit sedentary behavior by even modest amounts can have positive effects on health. In fact, for highly sedentary workers with metabolic disorders, such diabetes or hypertension, the short term benefits of reducing sitting time can be measured within days.  So, stand up, stretch, move, and adopt a variety of postures throughout the day--at home and work: these activities not only help reduce the deleterious health consequences of prolonged sitting, but also promote creativity, cognition, and reflection (Cranz, 2000; Jensen, 2005).

 

Any one posture--sitting or standing--can damage the body over time; epidemiological evidence highly suggests that postural variation is what we should strive for, both at work and at home.  Given the benefits afforded by movement and postural variation, these activities would ideally be designed into modern work and workplaces. Supportive interventions could include offering options for movement, fidgeting, stretching, and postural variation in conference rooms and other workplace settings, and integrating walking or standing meetings into workplace routines (Carlson & Sallis, 2017).  However, there is a note of caution. There is not so much evidence to support if this will affect long-term outcomes, such as cardiovascular disease events. Thus, there is insufficient epidemiological evidence to support the recommendation of sit/stand desks as a means to promote cardiovascular health, for example (Rempel & Krause, in press). Perhaps we will discover that, like sugar, too much is harmful, but that there is a time and place to sit and eat a nice piece of cake.

 

We at HealthyWorkplaces are taking on this issue of sedentary behavior as part of our Center’s broader interest in the physiological effects of working conditions. Last semester, with the help of undergraduate student Natalie Mutch, we began examining literature to understand what is currently known about the causes and effects of prolonged sitting, and how these insights might inform how we think about worker well-being both in and beyond the workplace.  We are now conducting a systematic literature review to get at those questions.

Here is a preview of a couple of interesting findings from our initial research:

Those who work in private offices typically sit more than their counterparts in open offices (Mullane et al., 2017).  This finding surprised us: people in private offices typically have more control over their workspace, and by extension, more freedom to stand or move around. In fact, what we realized is that private offices may in fact function as barriers to the movement-oriented social norms, social norms, health interventions, and impromptu meetings and periodic interruptions that can encourage breaks in sedentary time.  These contextual factors--including supportive managers and co-workers and workplace norms that support movement and postural variation--are essential to supporting individual behavior change (Hadgraft et al., 2017). Yet, too many workplace interventions to reduce sedentary behavior rely solely on individual behavior change, thereby limiting their potential efficacy in ameliorating this major threat to worker health (Baum & Fisher, 2014).    

Research focused first in evaluating the physiological changes that sedentary behaviors generate in the musculoskeletal system, but sedentary behaviors could also affect the circulatory, lymphatic, endocrine and excretory systems. The question is: how much sedentary behavior would be too much for whom? We hope to bring at least a preliminary answer soon.

 

 At the ICHW we are self-experimenting with solutions to stop prolonged sitting.

We’d like to hear from you!  
What have you seen at your workplace (or elsewhere) that helps reduce sitting or promote postural variation?  What do you do to sit less throughout the day?  Email us at ichw@berkeley.edu(link sends e-mail).

 

References and Suggested Reading

Baum F. & Fisher, M. (2014). Why behavioural health promotion endures despite its failure to reduce health inequities. Sociology of Health and Illness, 36, 213-225.

Carlson, J. A. & Sallis, J. F. (2017). Environment and policy interventions. In Zhu & Owen, Sedentary Behavior and Health: Concepts, Assessments, and Interventions (pp. 285-298). Champaign, IL: Human Kinetics.

Cranz, G. (2000). The Chair: Rethinking, Culture, Body, and Design. New York: W. W. Norton & Company.

Dunstan, D. W., Barr, E. L., Shaw, J. E., Magliano, D. J., Zimmet, P. Z., Salmon, J., . . . Balkau, B. (2010). Television viewing time and mortality: The Australian diabetes, obesity, and lifestyle study (AusDiab). Circulation, 121, 384-391.

Hadgraft, N. T., Willenberg, L., Lamontagne, A. D., Malkoski, K., Dunstan, D. W., Healy, G. N., . . . Lawler, S. P. (2017). Reducing occupational sitting: Workers’ perspectives on participation in a multi-component intervention. International Journal of Behavioral Nutrition and Physical Activity, 14(73).

Hamilton, M.T., Healy, G. N., Dunstan, D. W., Zderic, T. W., & Owen, N. (2008). Too little exercise and too much sitting: Inactivity physiology and the need for new recommendations on sedentary behavior. Current Cardiovascular Risk Reports, 2(4), 292-298.

Healy, G. N., Dunstan, D. W., Salmon, J., Cerin, E., Shaw, J. E., Zimmet, P. Z., & Owen, N. (2008).  Breaks in sedentary time: Beneficial associations with metabolic risk. Diabetes Care, 31(4), 661-666. Jensen, E. (2005). Teaching with the Brain in Mind, 2nd ed. Alexandria, VA: Association for Supervision and Curriculum Development.

Jensen, E. (2005). Teaching with the Brain in Mind, 2nd ed. Alexandria, VA: Association for Supervision and Curriculum Development.

Mullane, S. L., Toledo, M. J., Rydell, S. A., Feltes, L. H., Vuong, B., Crespo, N. C., . . . Buman, M. P. (2017). Social ecological correlates of workplace sedentary behavior.  International Journal of Behavioral Nutrition and Physical Activity, 14(1).

Owen, N. (2017). Emergence of research on sedentary behavior and health. In Zhu & Owen, Sedentary Behavior and Health: Concepts, Assessments, and Interventions (pp.  3-12). Champaign, IL: Human Kinetics.

Rempel, D. & Krause, N. (in press). Do sit-stand workstations improve cardiovascular health? Journal of Occupational and Environmental Medicine. DOI: 10.1097/JOM.0000000000001351.

Saunders, T. (2011, January 06). Can sitting too much kill you Retrieved June 25, 2018, from https://blogs.scientificamerican.com/guest-blog/can-sitting-too-much-kill-you/.

 

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