Category: In The News
A new review in the journal Mental Health and Physical Activity looks at the potential impact of sedentary behaviour on mental health:
It is generally understood that regular moderate to vigorous physical activity (MVPA) promotes good health from head to toe. Evidence also supports the notion that too much sitting can increase all-cause mortality and risk of chronic diseases such as diabetes. Moreover, there is evidence that daily MVPA may not offset negative effects of sedentary behavior on systemic risk factors. We extend the discussion to brain structure and function and argue that while MVPA is recognized as a protective behavior against age-related dementia, sedentary behavior may also be an important contributor to brain health and even counteract the benefits of MVPA due to overlapping or interacting mechanistic pathways. Thus, the goals of this review are (1) to outline evidence linking both PA and sedentary behavior to neurobiological systems that are known to influence behavioral outcomes such as cognitive aging and (2) to propose productive areas of future research.
The full article is now available via the journal Mental Health and Physical Activity.
Dr Meredith Peddie of the University of Otago (New Zealand) is currently looking for a PhD/MSc student to investigate the energy expenditure and possible dietary compensation associated with prolonged sitting, continuous physical activity, and regular activity breaks.
The full posting can be found below:
University of Otago Scholarships to undertake a PhD are available to those candidates with an excellent academic record.
A new study published in PLOS ONE suggests that sedentary behavior may not be associated with health independent of total physical activity. From the abstract:
Recent literature has posed sedentary behaviour as an independent entity to physical inactivity. This study investigated whether associations between sedentary behaviour and cardio-metabolic biomarkers remain when analyses are adjusted for total physical activity.
Cross-sectional analyses were undertaken on 4,618 adults from the 2003/04 and 2005/06 U.S. National Health and Nutrition Examination Survey. Minutes of sedentary behaviour and moderate-to-vigorous physical activity (MVPA), and total physical activity (total daily accelerometer counts minus counts accrued during sedentary minutes) were determined from accelerometry. Associations between sedentary behaviour and cardio-metabolic biomarkers were examined using linear regression.
Results showed that sedentary behaviour was detrimentally associated with 8/11 cardio-metabolic biomarkers when adjusted for MVPA. However, when adjusted for total physical activity, the associations effectively disappeared, except for C-reactive protein, which showed a very small, favourable association (β = −0.06) and triglycerides, which showed a very small, detrimental association (β = 0.04). Standardised betas suggested that total physical activity was consistently, favourably associated with cardio-metabolic biomarkers (9/11 biomarkers, standardized β = 0.08–0.30) while sedentary behaviour was detrimentally associated with just 1 biomarker (standardized β = 0.12).
There is virtually no association between sedentary behaviour and cardio-metabolic biomarkers once analyses are adjusted for total physical activity. This suggests that sedentary behaviour may not have health effects independent of physical activity.
The full study is available via the journal PLOS ONE.
New paper published in the American Journal of Preventive Medicine. The abstract:
Desk-based office employees sit for most of their working day. To address excessive sitting as a newly identified health risk, best practice frameworks suggest a multi-component approach. However, these approaches are resource intensive and knowledge about their impact is limited.
To compare the efficacy of a multi-component intervention to reduce workplace sitting time, to a height-adjustable workstations-only intervention, and to a comparison group (usual practice).
Three-arm quasi-randomized controlled trial in three separate administrative units of the University of Queensland, Brisbane, Australia. Data were collected between January and June 2012 and analyzed the same year.
Desk-based office workers aged 20-65 (multi-component intervention, n=16; workstations-only, n=14; comparison, n=14).
The multi-component intervention comprised installation of height-adjustable workstations and organizational-level (management consultation, staff education, manager e-mails to staff) and individual-level (face-to-face coaching, telephone support) elements.
MAIN OUTCOME MEASURES:
Workplace sitting time (minutes/8-hour workday) assessed objectively via activPAL3 devices worn for 7 days at baseline and 3 months (end-of-intervention).
At baseline, the mean proportion of workplace sitting time was approximately 77% across all groups (multi-component group 366 minutes/8 hours [SD=49]; workstations-only group 373 minutes/8 hours [SD=36], comparison 365 minutes/8 hours [SD=54]). Following intervention and relative to the comparison group, workplace sitting time in the multi-component group was reduced by 89 minutes/8-hour workday (95% CI=-130, -47 minutes; p<0.001) and 33 minutes in theworkstations-only group (95% CI=-74, 7 minutes, p=0.285).
A multi-component intervention was successful in reducing workplace sitting. These findings may have important practical and financial implications for workplaces targeting sitting time reductions.
The full study is available via the American Journal of Preventive Medicine.
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.
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.
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.
More Discussion Around SBRN’s Proposed Definition of Sedentary Behaviours Published in Applied Physiology, Nutrition and Metabolism
Earlier this year, SBRN published an updated definition of the terms “sedentary” and “sedentary behaviour” in response to confusion around the use of the terms in the published literature.
Recently, a letter to the editor by Ragnar Viir and Alar Veraksitš was published in Applied Physiology, Nutrition and Metabolism where concern with SBRN’s proposed definition of sedentary behaviour was expressed. The letter can be read in full here.
Dr. Mark Tremblay, a founding member of SBRN, has responded to this letter and his response can be read in full here.