The Heart Foundation of Australia has created a series of excellent workplace wellness posters targeting sedentary behaviour that can be printed off from their website.
Sit-Less PostersA range of four posters that act as a visual cue to prompt workers to stand or move more frequently in a workplace setting. These posters also provide imagery on ways that people can reduce extended sitting throughout the day.
Download your copies :
More workplace wellness resources are available via the Heart Foundation website.
Earlier this week we posted the abstract of a study concluding that sedentary behaviour may not have health effects independent of physical activity. David Dunstan and colleagues have responded with a comment on the article, available via PLOS ONE.
From the comment:
Maher and colleagues report findings from a secondary analysis of accelerometer data collected as part of the US National Health and Nutrition Examination Survey (NHANES). They found no associations of sedentary time with cardiometabolic risk biomarkers, when controlling for a measure of “total physical activity” that was composed of time spent in both moderate- to vigorous-intensity and light-intensity physical activity (that is, all non-sedentary time), weighted by intensity (accelerometer counts). On this basis, they concluded that sedentary time may not have health effects independent of physical activity. Leaving aside legitimate concerns with interpreting null results in this fashion, a broader conclusion that might be drawn is that there is limited (or no) merit in searching for “independent” effects of behaviours that are unavoidably “interdependent”.
Both the full article and the full comment are available via PLOS ONE.
New study suggests that prolonged sitting is linked to excess mortality. From Stone Hearth Newsletter:
Led by Cornell University nutritional scientist Rebecca Seguin, a new study of 93,000 postmenopausal American women found those with the highest amounts of sedentary time – defined as sitting and resting, excluding sleeping – died earlier than their most active peers. The association remained even when controlling for physical mobility and function, chronic disease status, demographic factors and overall fitness – meaning that even habitual exercisers are at risk if they have high amounts of idle time.
The full article is available via Stone Hearth Newsletter.
SBRN members have recently compiled a list of 12 different validated sedentary behaviour questionnaires, which are now available on the SBRN website. The questionnaires have been validated in age groups ranging from adolescence to the elderly, and in both population-based and clinical studies. If you have a questionnaire to add to the list (or a comment/correction) please email saunders (dot) travis (at) gmail (dot) com.
The full list is available here.
On October 28 the American Academy of Pediatrics updated their media/screentime recommendations for children and youth, published in the journal Pediatrics. The paper includes recommendations for healthcare providers, schools, and parents.
Recommendations for parents:
- Limit the amount of total entertainment screen time to < 1 to 2 hours per day.
- Discourage screen media exposure for children < 2 years of age.
- Keep the TV set and Internet-connected electronic devices out of the child ’ s bedroom.
- Monitor what media their children are using and accessing, including any Web sites they are visiting and social media sites they may be using.
- Co-view TV, movies, and videos with children and teenagers, and use this as a way of discussing important family values.
- Model active parenting by establishing a family home use plan for all media. As part of the plan, enforce
a mealtime and bedtime “ curfew ” for media devices, including cell phones. Establish reasonable but
ﬁrm rules about cell phones, texting, Internet, and social media use.
The full set of recommendations are available in the journal Pediatrics.
From the American Journal of Preventive Medicine:
Associations of sitting-time and physical activity with depression are unclear.
To examine concurrent and prospective associations between both sitting-time and physical activity with prevalent depressive symptoms in mid-aged Australian women.
Data were from 8950 women, aged 50-55 years in 2001, who completed mail surveys in 2001, 2004, 2007, and 2010. Depressive symptoms were assessed using the Center for Epidemiological Studies Depression questionnaire. Associations between sitting-time (≤4 hours/day, >4-7 hours/day, >7 hours/day) and physical activity (none, some, meeting guidelines) with depressive symptoms (symptoms/no symptoms) were examined in 2011 in concurrent and lagged mixed-effect logistic modeling. Both main effects and interaction models were developed.
In main effects modeling, women who sat >7 hours/day (OR=1.47, 95% CI=1.29, 1.67) and women who did no physical activity (OR=1.99, 95% CI=1.75, 2.27) were more likely to have depressive symptoms than women who sat ≤4 hours/day and who met physical activity guidelines, respectively. In interaction modeling, the likelihood of depressive symptoms in women who sat >7 hours/day and did no physical activity was triple that of women who sat ≤4 hours/day and met physical activity guidelines (OR 2.96, 95% CI=2.37, 3.69). In prospective main effects and interaction modeling, sitting-time was not associated with depressive symptoms, but women who did no physical activity were more likely than those who met physical activity guidelines to have future depressive symptoms (OR=1.26, 95% CI=1.08, 1.47).
Increasing physical activity to a level commensurate with guidelines can alleviate current depression symptoms and prevent future symptoms in mid-aged women. Reducing sitting-time may ameliorate current symptoms.
For links to other sedentary behaviour studies, please visit the SBRN Research Database.
Today’s guest post comes from PhD student Bethany Howard. You can find out more about Bethany at the bottom of this post. The study that she is discussing was recently published in MSSE, and can be found here.
I am sure by now you have all heard the messages to avoid your chair and the increased risk of premature death it may be kindly bestowing on you. Indeed there are slogans out there such as “your chair is sending you to an early grave”, “make a stand”, “sitting is the new smoking” and big corporations that promote this important rapidly evolving area of research – that is the study of the health consequences of “too much sitting”.
What do we know?
It’s important to appreciate that these messages about the hazards of sitting are not entirely new – as early as the 1950’s physicians were advocating breaks from sitting. Homans (1954) suggested that the “Such matters are important enough to suggest the advisability of making movement of the toes, feet and lower legs when one is sitting for long periods and of getting up and exercising when opportunity offers.” Such recommendations were drawn from cases of thrombosis – the formation of a blood clot that obstructs blood flow – with prolonged sitting at the theatre, whist watching TV and during travel.
Today the research initiated from such early work is now evident in the recommendations when we fly. For those of you who are avid jetsetters you will be familiar with the announcement to “get up and move around to reduce the risk of deep vein thrombosis (VT)”. There is now evidence to suggest that this increased risk extends to prolonged bus travel and prolonged workplace sitting. But the question we wanted to ask with our experimental study published recently in Medicine & Science and Sports & Exercise was:
What are the potential reasons for this increased risk?
Virchow describes three components that contribute to the risk of VT, known commonly as Virchows Triad: Impaired blood flow, Hyper-coagulation and Disturbed Endothelium. Of these, there is substantial evidence linking sitting to impaired blood flow, limited evidence on hypercoagulation and little or no evidence for possible effects on the endothelium. The majority of studies that have been conducted in this area have focused on air travel. Although high amounts of sitting are present, air travel does not provide the typical environment in which sitting accumulates in our daily lives.
What did we do?
In order to address these knowledge gaps, we used an experimental study design to examine the effects of sitting (uninterrupted) on markers of thrombosis, specifically markers that relate to clot formation (through haemostasis) and blood viscosity. We then compared these effects to interrupted sitting, to assess whether breaks involving walking were indeed effective at reducing thrombotic risk. To do this we undertook an acute randomized cross-over trial design with subjects being their own controls. The trial consisted of 3 conditions all of which lasted for 7 hours:
1) Uninterrupted sitting
2) Sitting interrupted by light-intensity walking breaks
3) Sitting interrupted by moderate-intensity walking breaks
The two different intensity activity break conditions were incorporated into the study design to determine if there is an intensity effect of the breaks. That is, for a benefit to be seen, do the breaks need to be of a higher intensity? Earlier observational work from our group using objective activity monitoring suggested that the intensity wasn’t as important – having breaks, and frequently seemed most important.
What did we find?
For the common blood viscosity markers (plasma volume, hematocrit, hemoglobin, red blood cells) breaks were beneficial irrespective of the intensity. That is, with the introduction of breaks in sitting time blood viscosity appeared to be reduced. This is likely to have improved blood flow, one of three elements of Virchows triad. Continue Reading
The American College of Sports Medicine will be hosting their annual scientific meeting in Indianapolis, USA, this week, and there is a wealth of sedentary behaviour research on the program. You can find a full list of the presentations related to sedentary behaviour here.
The below presentations will be led by members of SBRN. If you are giving a presentation related to sedentary behaviour at ACSM or another conference, send the presentation time and location to Travis Saunders at tsaunders (at) cheo (dot) on (dot) ca.
Sedentary/active Behaviors And Cardiometabolic Risk: Protective Effects Of Sleep Duration, Nhanes 2005-2006. Matthew P. Buman, Elisabeth A. H. Winkler, Jonathan M. Kurka, Eric B. Hekler, Neville Owen, Barbara E. Ainsworth, Genevieve N. Healy, Paul A. Gardiner. Session: Thematic Poster B-18. Sedentary Behavior: Effects on Health Wednesday, May 29, 2013 1:00 – 3:00 PM
Sedentary Behaviour, Visceral Fat And Cardiometabolic Risk: 6-year Longitudinal Study From The Quebec Family Study. Travis J. Saunders, Mark S. Tremblay, Jean-Pierre Després, Claude Bouchard, Angelo Tremblay, Jean-Philippe Chaput. Session: Thematic Poster B-18. Sedentary Behavior: Effects on Health Wednesday, May 29, 2013 1:00 – 3:00 PM.
Sedentary Behavior and Cardiometabolic Risk: Emerging Experimental Evidence. SBRN members presenting during this session include Neville Owen (Chair), Sarah Kozey-Keadle (Does Reducing Sedentary Behavior Enhance the Benefits of Exercise?), Travis Saunders (The Metabolic and Behavioral Impact of One Day of Prolonged Sitting in Children and Youth) and David Dunstan (Understanding the Acute and Cumulative Metabolic Effects of Prolonged Sitting in Adults).
Objective: Sedentariness is associated with weight gain and obesity. A treadmill desk is the combination of a standing desk and a treadmill that allow employees to work while walking at low speed.
Design and Methods: The hypothesis was that a 1-year intervention with treadmill desks is associated with an increase in employee daily physical activity (summation of all activity per minute) and a decrease in daily sedentary time (zero activity). Employees (n = 36; 25 women, 11 men) with sedentary jobs (87 ± 27 kg, BMI 29 ± 7 kg/m2, n = 10 Lean BMI < 25 kg/m2, n = 15 Overweight 25 < BMI < 30 kg/m2, n = 11 Obese BMI > 30 kg/m2) volunteered to have their traditional desk replaced with a treadmill desk to promote physical activity for 1 year.
Results: Daily physical activity (using accelerometers), work performance, body composition, and blood variables were measured at Baseline and 6 and 12 months after the treadmill desk intervention. Subjects who used the treadmill desk increased daily physical activity from baseline 3,353 ± 1,802 activity units (AU)/day to, at 6 months, 4,460 ± 2,376 AU/day (P < 0.001), and at 12 months, 4,205 ± 2,238 AU/day (P < 0.001). Access to the treadmill desks was associated with significant decreases in daily sedentary time (zero activity) from at baseline 1,020 ± 75 min/day to, at 6 months, 929 ± 84 min/day (P < 0.001), and at 12 months, 978 ± 95 min/day (P < 0.001). For the whole group, weight loss averaged 1.4 ± 3.3 kg (P < 0.05). Weight loss for obese subjects was 2.3 ± 3.5 kg (P < 0.03). Access to the treadmill desks was associated with increased daily physical activity compared to traditional chair-based desks; their deployment was not associated with altered performance. For the 36 participants, fat mass did not change significantly, however, those who lost weight (n = 22) lost 3.4 ± 5.4 kg (P < 0.001) of fat mass. Weight loss was greatest in people with obesity.
Conclusions: Access to treadmill desks may improve the health of office workers without affecting work performance.
A list of other studies on the health impact of sedentary behaviour can be found in the SBRN Research Database.
The 2014 Global Summit on the Physical Activity of Children — “The Power to Move Kids” — which takes place in Toronto from May 19th-22nd, 2014, will bring together those who are working to resolve the growing childhood physical inactivity crisis. Anyone whose work touches physical activity for children, including researchers, practitioners and policy-makers, should count this among the must-attend events for 2014.
Please see below for some updates on the 2014 Summit.
Summit Registration is Now Open!
We are off and running – registration for the 2014 Global Summit on the Physical Activity of Children and Youth is now open. Secure your attendance at this must-attend event for anyone whose work touches childhood physical activity.
Call For Abstracts is Online
Share your expertise with an international audience and be part of the resolution of the global childhood inactivity crisis.
The call for abstract submissions is now open for oral presentations, promising practice workshops (sharing successes) and poster presentations with either a research or practice focus.