SBRN members Sebastien Chastin and colleagues have recently published the results of the first round of their Sedentary Behaviour Taxonomy project.
The abstract (via PLOS ONE):
Over the last decade, sedentary behaviors have emerged as a distinctive behavioral paradigm with deleterious effects on health independent of physical activity. The next phase of research is to establish dose response between sedentary behaviors and health outcomes and improve understanding of context and determinants of these behaviors. Establishing a common taxonomy of these behaviors is a necessary step in this process.
The Sedentary behavior International Taxonomy project was developed to establish a classification of sedentary behaviors by use of a formal consensus process.
The study follows a Delphi process in three Rounds. A preparatory stage informed the development of terms of reference documents. In Round 1, experts were asked to make statements about the taxonomy; 1) its purpose and use ; 2) the domains, categories or facets that should be consider and include; 3) the structure/architecture to arrange and link these domains and facets. In Round 2 experts will be presented with a draft taxonomy emerging from Round 1 and invited to comment and propose alterations. The taxonomy will then be finalised at the outset of this stage.
Results of Round 1 are reported here. There is a general consensus that a taxonomy will help advances in research by facilitating systematic and standardised: 1) investigation and analysis; 2) reporting and communication; 3) data pooling, comparison and meta-analysis; 4) development of measurement tools; 4) data descriptions, leading to higher quality in data querying and facilitate discoveries. There is also a consensus that such a taxonomy should be flexible to accommodate diverse purposes of use, and future advances in the field and yet provide a cross-disciplinary common language. A consensual taxonomy structure emerged with nine primary facets (Purpose, Environment, Posture, Social, Measurement, Associated behavior, Status, Time, Type) and the draft structure presented here for Round 2.
The full paper is available for free via the journal PLOS ONE.
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.
Today’s post comes from Dr Dylan Cliff, a National Heart Foundation Postdoctoral Research Fellow at the University of Wollongong (Australia).
Many people interested in young people’s development are now aware that sedentary behaviours, particularly too much television viewing, can be harmful to health during childhood and adolescence. There are, however, currently a wide variety of approaches being used to measure sedentary behaviours in young people. This can make things confusing for those who are new to sedentary behaviour research such as clinicians, health promoters, educators, and researchers from different fields. It is important that researchers, practitioners and policy makers understand the strengths and weaknesses of different methods of assessing sedentary behaviours among young people, and have easy access to information about the most appropriate instruments to suit their needs.
With this in mind, members of the Physical Activity and Sedentary Behaviour Stream of the Australasian Child and Adolescent Obesity Research Network (ACAORN) have recently developed an online Method Selection Guide and published an accompanying ‘Hitchhiker’s Guide‘ to assist users in choosing instruments to measure sedentary behaviours among children and adolescents. This followed on from a systematic review conducted by the Stream to summarise the evidence on the validity and reliability of available measures of sedentary behaviours.
For the Method Selection Guides, Stream members developed decision flow charts to assist users in selecting an appropriate measure, identified attributes of each method and described five case scenarios to illustrate considerations associated with the selection of each method of measurement. The scenarios included a screen time intervention among preschoolers, a school-based intervention to reduce sitting during class-time among children, a treatment program for overweight/obese school children focused on reducing sedentary time, the primary prevention of adolescent screen time in a clinical setting, and an observational study to estimate the population prevalence of screen time among adolescents. In developing the Method Selection Guides, ACAORN’s Physical Activity and Sedentary Behaviour Stream aim to assist researchers and practitioners interested in understanding more about the measurement of sedentary behaviours in children and adolescents.
You can access the Method Selection Guide for free at http://www.acaorn.org.au/streams/activity/method-selection/sedentary.php.
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.
Measuring Muscle Visco-Elasticity in Horizontal Bed Rest Model for Better Understanding of Sedentary Life Style
R. Viir, Institute of Exercise Biology and Physiotherapy, University of Tartu, TartuEstonia
RehabCenter, RheumatismFoundationHospital, Heinola, Finland
M. Pääsuke, Institute of Exercise Biology and Physiotherapy, University of Tartu, TartuEstonia
K. Rajaleid, Center for Health Equity Studies, StockholmUniversity/ Karolinska Institutet, Stockholm, Sweden
*Note: The source for this paper is the 2008 ISU 12th Annual Symposium – ‘Space Solutions to Earth’s Global Challenges’
The aim of this study was to use the upper trapezius muscle as a representative of the musculoskeletal support system to determine the effect on muscle tension due changing from upright position to a lying position and whether this change could be useful in the prevention of musculoskeletal disorders. Twenty two female subjects participated in this study. Myometric measurements of the upper trapezius muscle on both sides of the body were recorded in a standing, sitting and supine position. Changing from upright positions to a supine position reduced the upper trapezius muscle support function by up to one fifth as characterized with diminishing of muscle tone and stiffness. The change in tone and stiffness of the trapezius muscle is of significance to the well being of sedentary workers. Introducing regular brief breaks of simple unchallenging movements while being in a supine position should enhance recovery from prolonged sitting.
Prevention magazine recently featured a list of 100 ways to break up your sedentary time on. From their website:
1. Hide your remote. If you must watch TV, at least stand up to change the channel.
2. When cooking or baking, ditch the hand mixer and use a wooden spoon instead.
3. Take each family member’s laundry upstairs separately.
4. When tidying up, put things away in multiple small trips rather than one big haul.
5. Chop fresh vegetables instead of buying frozen ones.
6. Invest in quality pots and pans; the heavier they are, the more energy it’ll take to use them.
7. Paint, hang curtains, or finish any other home-improvement task on your to-do list.
8. Stand up and march during your favorite TV shows. (Try our Couch-Potato Workout.)
9. Rather than yell toward family members in other rooms, walk over to talk.
10. Stand while styling your hair and putting on makeup.
11. Walk around your home, yard, or neighborhood while on the phone.
12. Hand-wash dishes instead of using the dishwasher.
13. Wash your car instead of taking it through the car wash.
14. Put most-used items on top or bottom shelves so you have to reach for them.
15. Leave your cell phone in one location, so when you need it, you must go to it.
16. Start a compost pile in your yard.
17. Help your kids clean their rooms.
18. Organize a closet.
19. Rake the leaves as a family.
20. Give the delivery guy a break; when you order food in, pick it up yourself.
21. Take a shower instead of a bath.
22. Walk to the mailbox instead of checking the mail from your car.
23. Plant or weed a garden or care for indoor plants.
24. Ask for the paper to be left at the end of your driveway instead of by your front door.
25. Give your dog a bath instead of paying someone else to do it.
26. Instead of sitting and reading, listen to books on tape as you walk, clean, or garden.
27. Preset the timer on your TV to turn off after an hour to remind you to do something more active.
28. Slide a small trampoline under your couch and pull it out for Real Housewives marathons.
29. Put up more Christmas lights.
30. The next time it snows, up your karma and shovel your neighbor’s sidewalk too.
31. Turn on tunes and dance while cooking.