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Diabetes Prevention
‘Too Much Sitting’ and Metabolic Risk—
Has Modern Technology Caught Up with Us?
David W Dunstan, PhD,
1,2,3,4,5
Genevieve N Healy, PhD,
1,3
Takemi Sugiyama, PhD
3
and Neville Owen, PhD
3
1. Baker IDI Heart and Diabetes Institute, Melbourne; 2. Department of Epidemiology and Preventive Medicine, Monash University, Melbourne;
3. Cancer Prevention Research Centre, School of Population Health, The University of Queensland;
4. School of Exercise and Nutrition Sciences, Deakin University, Melbourne; 5. Vario Health Institute, Edith Cowan University, Perth
Abstract
Recent epidemiological evidence suggests that prolonged sitting (sedentary behavior: time spent in behaviors that have very low
energy expenditure, such as television viewing and desk-bound work) has deleterious cardiovascular and metabolic correlates, which
are present even among adults who meet physical activity and health guidelines. Further advances in communication technology and
other labor-saving innovations make it likely that the ubiquitous opportunities for sedentary behavior that currently exist will become even
more prevalent in the future. We present evidence that sedentary behavior (too much sitting) is an important stand-alone component
of the physical activity and health equation, particularly in relation to cardio-metabolic risk, and discuss whether it is now time to consider
public health and clinical guidelines on reducing prolonged sitting time that are in addition to those promoting regular participation in
physical activity.
Keywords
Sedentary behavior, sitting time, physical inactivity, cardio-metabolic risk
Disclosure: The authors have no conflicts of interest to declare.
Acknowledgments: We wish to express our thanks to Associate Professor Jo Salmon, Deakin University for her assistance in the conceptualization and production of Figure 3.
Received: May 21, 2009 Accepted: September 7, 2009
Correspondence: David W Dunstan, PhD, Baker IDI Heart and Diabetes Institute, 250 Kooyong Road, Caulfield, Victoria, Australia, 3162. E: david.dunstan@bakeridi.edu.au
There is general recognition among physicians and other health the plethora of sedentary behaviors that occupy the waking hours
professionals that regular participation in moderate- to vigorous- of most adults.
intensity physical activity (i.e. brisk walking, jogging, lap-swimming) is
one of the cornerstones of chronic disease prevention and For instance, for a person who typically sleeps eight hours per day,
management. In addition to the physical and psychological benefits, meeting the minimum public health physical activity levels of 30
there is considerable evidence that moderate- to vigorous-intensity minutes of moderate- to vigorous-intensity activity each day constitutes
activity has a positive influence on cardio-metabolic risk factors.
1
As a only a small proportion of the remaining 16 hours in his or her day (see
consequence, public health campaigns and recommendations Figure 1). Indeed, recent studies that have used accelerometers to
regarding advice that may be provided by health professionals have objectively measure daily physical activity among Australian adults have
typically focused on this intensity of physical activity, with current identified that, on average, the majority of adults’ non-sleeping hours
recommendations supporting the accumulation of at least 30 minutes (up to 60%) is spent in sedentary time, with the remainder being
of moderate to vigorous activity on at least five days of the week.
1
disproportionally distributed to light-intensity (incidental movement)
(35%), and only a small fraction of time to moderate to vigorous physical
While there has been some success with these public health activities (usually less than 5%; see
3
Figure 2).
campaigns, evident through the population-wide increases in leisure-
time physical activity being observed in some countries over the past Sedentary time, derived from the Latin word ‘sedere’ meaning ‘to sit’,
10 years, this success has also coincided with a rapid rise in the represents the time that individuals spend in various behaviors that
prevalence of overweight and obesity in several countries over the require low energy expenditure such as working on the computer,
same period.
2
Several factors may explain this apparent paradox. The watching television, or driving a car. Sedentary behavior, often used
most plausible explanation is the sole focus on an important, but interchangeably with sedentary time, is the term now used to
limited, element of the overall physical activity spectrum: moderate- collectively characterise those behaviors that people encounter at
to vigorous-intensity activities. Focusing on this single component home, at work, and during leisure and transportation that involve
does not address the health consequences of participation in prolonged sitting rather than ambulatory movement.
4–6
© TOUCH BRIEFINGS 2009 29
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