A new study in the European Heart Journal has investigated the impact of (statistically) replacing sitting with standing or walking. The abstract:
Aims While excessive sitting time is related adversely to cardio-metabolic health, it is unknown whether standing is a suitable replacement activity or whether ambulatory movement is required. Using isotemporal substitution analyses, we modelled cross-sectional associations with cardio-metabolic risk biomarkers of reallocating time (2 h/day) from sitting to standing or to stepping.
Methods and results A subsample of participants from the 2011/12 Australian Diabetes, Obesity, and Lifestyle Study wore the posture-based activPAL3 monitor [36–80 years (mean 57.9, SD 9.9 years); 57% women; n = 698 with data]. Associations of activPAL3-derived mean daily time sitting/lying (sitting), standing and stepping with body mass index (BMI), waist circumference, blood pressure, HbA1c, fasting glucose and lipids (high-density lipoprotein-, HDL, and low-density lipoprotein-cholesterol, total/HDL-cholesterol ratio, and triglycerides), and 2-h plasma glucose were examined. Adjusted for relevant confounders, sitting-to-standing reallocations were only significantly (P < 0.05) associated with approximately 2% lower fasting plasma glucose, 11% lower triglycerides, 6% lower total/HDL-cholesterol ratio, and 0.06 mmol/L higher HDL-cholesterol per 2 h/day. Sitting-to-stepping reallocations were only significantly associated with approximately 11% lower BMI, 7.5 cm lower waist circumference, 11% lower 2-h plasma glucose, 14% lower triglycerides, and 0.10 mmol/L higher HDL-cholesterol per 2 h/ day, while standing-to-stepping reallocations were only significantly associated with ∼10% lower BMI, 7 cm lower waist circumference, and 11% lower 2-h plasma glucose.
Conclusion Findings suggested that sitting-reduction strategies targeting increased standing, stepping, or both, may benefit cardio-metabolic health. Standing is a simple alternative to sitting, and requires further examination in prospective and intervention studies.
The full paper is available for free via the European Heart Journal website.
A systematic review exploring the link between sedentary behaviour and anxiety was published recently in the journal BMC Public Health.
Previous research has linked sedentary behaviour (SB) to adverse physical health outcomes in adults and youth. Although evidence for the relationship between SB and mental health outcomes (e.g., depression) is emerging, little is known regarding risk of anxiety.
A systematic search for original research investigating the association between SB and risk of anxiety was performed using numerous electronic databases. A total of nine observational studies (seven cross-sectional and two longitudinal) were identified. Methodological quality of studies was assessed and a best-evidence synthesis was conducted.
One cross-sectional study demonstrated a strong methodological quality, five cross-sectional studies demonstrated a moderate methodological quality and three studies (two cross-sectional one longitudinal) received a weak methodological quality rating. Overall, there was moderate evidence for a positive relationship between total SB and anxiety risk as well as for a positive relationship between sitting time and anxiety risk. There was inconsistent evidence for the relationship between screen time, television viewing time, computer use, and anxiety risk.
Limited evidence is available on the association between SB and risk of anxiety. However, our findings suggest a positive association (i.e. anxiety risk increases as SB time increases) may exist (particularly between sitting time and risk of anxiety). Further high-quality longitudinal/interventional research is needed to confirm findings and determine the direction of these relationships.
The full review is available for free via the BMC Public Health website.
Last week an Expert Statement commissioned by Active Working CIC and Public Health England was published in the British Journal of Sports Medicine titled “The Sedentary Office: a growing case for change towards better health and productivity” (available here).
From the Get Britain Standing website:
Based on the current evidence Active Working recommends:
- 2 hours daily of standing and light activity (light walking) during working hours, eventually progressing to a total of 4 hours for all office workers whose jobs are predominantly desk based
- Regularly breaking up seated based work with standing based work, with the use of adjustable sit-stand desks/work stations
- Avoidance of prolonged static standing, which may be as harmful as prolonged sitting
- Altering posture/light walking to alleviate possible musculoskeletal pain and fatigue as part of the adaptive process
- As well as encouraging staff to embrace other healthy behaviours, such as cutting down on drinking and smoking, eating a nutritious diet, and alleviating stress, employers should also warn their staff about the potential dangers of too much time spent sitting down either at work or at home
The full Expert Statement is available here.
This is one of the questions that will be addressed at the upcoming, Loch Lomond Lectures – Context is Key: Unlocking Physical Behaviour Data.
This event is a small, informal and participative retreat style meeting hosted by Malcolm Granat, Professor of Health and Rehabilitation Sciences, School of Health Science, University of Salford, and featuring several renowned international speakers.
When: 7 & 8 June 2015
Location: Loch Lomond, Scotland
March 23-29 is Unplug and Play Week in Canada. From ParticipACTION:
Turn off the screens. Turn up the play.
Now that our electronics are only ever a finger’s reach away, the average Canadian child spends close to 8hrs a day in front of a screen. So let’s help our children by leading by example. Let’s put our electronics down for at least 60 minutes a day and get outside for some physical activity. To help, here’s an Unplug & Play Checklist with a week’s worth of ideas. You’ll also find a customizable certificate to award your little ones if they stay active for all 7 days.
The site also offers a screen time log to track screen time. Happy Unplug and Play Week!
There will be an event titled ‘Physical activity & sedentary behaviour surveillance & assessment – maximizing Europe’s resources” at the EXPO in Milan on 14 May.
Please see the program attached or check the registration website:
A pdf providing an overview of the workshop can be found below.
Author Summary of “Sedentary Time and Its Association with Risk for Disease Incidence, Mortality, and Hospitalization in Adults” paper, Published in the Annals of Internal Medicine (2015: 162:123-132)
Today’s post is a summary of a fascinating new paper published in Annals of Internal Medicine on the relationship between sedentary behaviour and premature mortality (available here). The summary is written by lead author Avi Biswas; you can find more on Avi at the bottom of this post. This post is also available at PLoS Blogs.
In a similar vein to other reviews that have examined the association between sedentary time and various health outcomes, our study sought to not only update the sedentary behavior literature but also focus exclusively on studies that adjusted for physical activity in order to assess the independent effects of sedentary time. This differentiated our meta-analysis from two others which had previously reported independent risks (Wilmot et al., 2012 and Schmid and Leitzmann, 2014), as investigating the independent effects of sedentary time (by reporting the effects from studies that at least adjusted for physical activity) was our core focus rather than among a limited subgroup of available studies. Additionally, our study examined the extent to which levels of physical activity may potentially modify the associations between sedentary time and outcomes, which to the best of our knowledge has not been systematically quantified in other reviews.
What we did
We devised a comprehensive, systematic search strategy of studies that assessed sedentary behavior in adults as a predictor variable and correlated to at least one health outcome. We also focused on direct clinical outcomes (death, disease incidence and health service use) rather than indirect surrogate outcomes such as quality of life, insulin sensitivity and weight gain) as we believed the later type would present inconsistent end points and cutoffs. We then collected the statistical effects associated with the longest reported sedentary time (vs. a baseline of the lowest sedentary time) and that adjusted for physical activity. These were used to pool the analysis of the overall effect for each outcome.
When examining whether physical activity modifies the effects associated with sedentary time, we reanalyzed all available studies that met our selection criteria to see if they reported statistical effects of the longest period of sedentary time with the highest duration and intensity of physical activity.
What we found
Our study found that long periods of sedentary time was positively associated with an increased risk for dying (from all-causes, cancer and cardiovascular diseases) and increasing the risk for certain forms of cancer (specifically breast, colon, colorectal, endometrial, and epithelial ovarian cancer), cardiovascular disease and type 2 diabetes. Our meta-analysis found that the largest association was with type 2 diabetes (91% increased risk).
Of the limited studies that reported the joint effects of physical activity and sedentary time (only quantified for dying from all-causes), our pooled analysis found that the risk of dying from all-causes due to long sedentary time was 30% greater in those who spent little to no time in regular physical activity than those who at least met their physical activity recommendations of 30 minutes/day. While the pooled effect corresponding to high levels of physical activity and long sedentary time were found not to be statistically significant, we believe the consistent and strong effects associated across all-cause mortality-assessed studies (and to a lesser degree, cardiovascular disease and mortality) suggests that there is a strong likelihood that physical activity alone does not completely reduce the negative effects from long sitting time. We believe more work needs to be done to tease out whether there is such an association.
Take home message
Our study provides the strongest evidence as so far, to suggest that long periods of sitting is associated with various health outcomes. Furthermore, while regular or high levels of physical activity seems to have protective effects on reducing sedentary time-associated risks, we believe there is sufficient evidence to suggest that a focus on promoting regular exercise AND reducing sitting time to be a better public health message.
About the Authors
Avi is a PhD candidate at the Institute of Health Policy, Management and Evaluation, University of Toronto and the Toronto Rehabilitation Institute. Along with this meta-analysis study, his PhD work is focused on understanding the risks of sedentary behaviour among exercise-engaged cardiac rehabilitation patients, in lieu of developing non-sedentary interventions.
Dr. Alter is a Senior Scientist at the Institute of Clinical Evaluative Sciences and research director of the Toronto Rehabilitation Institute’s Cardiovascular Prevention and Rehabilitation program. Dr. Alter’s research spans across many disciplines including cardiovascular health services and outcomes, clinical epidemiology and social determinants, cardiac rehabilitation and more recently, music and medicine. He has published over 125 scholarly peer reviewed papers in prestigious journals such as the New England Journal of Medicine and the Journal of the American Medical Association. Dr. Alter has also received funding from various agencies including the Heart and Stroke Foundation of Ontario.
Today’s post comes from PhD Candidate Justin Lang. For media requests or further information on the study, please contact Justin directly at jlang
In recent years there has been an accumulation of evidence indicating that sedentary behaviors (i.e., sitting) are associated with negative health outcomes, such as cardiovascular disease, diabetes, and premature mortality. In light of this evidence, researchers are trying to develop creative interventions to reduce sedentary behaviors – one of which being point-of-decision prompts (PODP). PODPs are used to inform individuals about the health benefits associated with a specific behavior. For instance, PODP are used in the workplace to remind people to stand throughout the day; they are also used to encourage individuals to use the stairs rather than the elevator.
We were interested in testing PODPs as an intervention to encourage standing during the Global Summit on the Physical Activity of Children and Youth conference (Toronto, Ontario, May 2015). Conferences are an excellent venue for sedentary behavior research as they typically involve periods of uninterrupted sitting, especially during oral presentation. Thus, the purpose of our study was to determine if a PODP would influence the proportion of attendees standing during oral presentations.
What did we do?
We selected 12 of 16 oral presentation sessions that took place during the conference. Each presentation session included 4 different, 15 minute, oral presentations on various topics related to physical activity. We then randomly assigned 6 presentation sessions to the intervention group and the remaining 6 presentation sessions to the control group.
During the intervention group sessions we asked the facilitators to read the prompt (see below) at the beginning (before the first presenter) and middle (after the second presenter) of the session.
Prolonged sitting is associated with increased health risks. We encourage you to reduce and/or interrupt your sedentary time while attending the Global Summit on the Physical Activity of Children. Please feel free to stand during this presentation session.
Facilitators for the control group sessions were asked not to address sitting and/or standing, and to not mention the existence of the study.
During all 12 sessions, researchers counted the number of participants at the beginning (first 10 min), middle (30-40 min), and end (50-60 min) of the session. Each count consisted of (a) the number of individuals in the room and (b) the number of standing individuals at any time during the count period.
What did we find?
The results of this study indicated that individuals were significantly more likely to stand during presentation sessions that included the PODP (see Figure 1). Roughly 60% more participants stood during the sessions with the PODP, when compared to the control group.
Our study suggests that frequent prompts and/or permission to stand results in a great proportion of people choosing to do so. This is an exciting finding because it supports the versatility of PODPs. Prompts represent an equitable population health intervention. In other words, they have the potential to influence a large group of individuals equally. In addition, PODPs have little to no cost associated with their implementation.
About the author:
Justin Lang is a PhD candidate in the Population Health program at the University of Ottawa and holds a research assistantship with the Healthy Active Living and Obesity Research Group at CHEO. His PhD research focus is on the geographic variation of physical fitness in children and it’s relationship with childhood obesity. Justin also holds a Mitacs internship which provides him with the opportunity to further explore physical fitness in the Ottawa community.
Lang, J. J., McNeil, J., Tremblay, M. S., & Saunders, T. J. (2015). Sit less, stand more: A randomized point-of-decision prompt intervention to reduce sedentary time. Preventive Medicine. Available here.
A systematic review and meta-analysis on the link between sedentary time and health outcomes in adults that was published today is receiving significant attention in the media. The title of the paper is, “Sedentary Time and Its Association With Risk for Disease Incidence, Mortality, and Hospitalization in Adults: A Systematic Review and Meta-analysis,” and was published in the Annals of Internal Medicine today. Note: several SBRN members are among the authors on the paper.
According to Dr. David Alter, lead researcher of the study and a senior scientist at the Toronto Rehabilitation Institute, “More than one half of an average person’s day is spent being sedentary — sitting, watching television or working at a computer. Our study finds that despite the health-enhancing benefits of physical activity, this alone may not be enough to reduce the risk for disease.”
Click on the links below to follow media coverage on this study:
- Excessive sitting linked to disease, premature death – Globe & Mail
- Sitting for too long can kill you, even if you exercise: study – CBC
- Too much sitting raises risk of death, even if you exercise – Full Time Whistle
- Sitting All Day Sitting Linked To Disease, Premature Death Even With Regular Exercise – Huffington Post
- Sitting on your butt too much may be deadly: study – Metro
- Too Much Sitting Linked to Increased All-Cause Mortality – Medscape
- Sitting too long increases risk of dying early – SMN Weekly
- Even with exercise, excessive sitting may be deadly – Missions Record
- Even with regular exercise, excessive sitting linked to disease, premature death – News 1130
- Even for the active, a long sit shortens life and erodes health – LA Times
- Exercising regularly WON’T offset the risk of sitting for long periods of time: An hour of activity a day isn’t enough to stave off heart disease, diabetes and cancer, study finds – Daily Mail UK
- It Doesn’t Matter How Much You Exercise If You Also Do This – Time
Biswas A, Oh PI, Faulkner GE, Bajaj RR, Silver MA, Mitchell MS, Alter DA. Sedentary Time and Its Association With Risk for Disease Incidence, Mortality, and Hospitalization in Adults: A Systematic Review and Meta-analysis. Ann Intern Med. 2015 Jan 20;162(2):123-132. doi: 10.7326/M14-1651.
Today’s post comes from Mai Chinapaw and Teatske Altenburg. Their lab website can be found here.
A recent commentary by Chinapaw et al. (Prev Med 2014) critically discussed the current evidence on the association between sedentary behaviour and cardiometabolic health in children. The authors conclude that in children, there is no convincing evidence yet on the association between sedentary behaviour and cardiometabolic health. One of the highlighted challenges to advance this field is improving the measurement of sedentary behaviour including total sedentary time and sedentary time accumulated in bouts. Two recent papers examined this important issue.
The first paper (Chinapaw et al., PLoS ONE 2014) aimed to establish evidence-based accelerometer data reduction criteria for assessment of sedentary behaviour patterns in children. This is the first study that examined the influence of data reduction procedures on the number or duration of sedentary bouts in children. The authors formulated the following recommendations: 1) a minimum of 60 minutes of consecutive zeros as the most realistic criterion for non-wear time; and 2) including at least six days with minimum eight valid hours to characterize children’s usual total sedentary time and sedentary time accumulated in bouts, preferably including one weekend day.
The second paper (Altenburg et al., Prev Med 2015) examined occurrence and durations of bouts based on various definitions (bouts of at least 5, 10, 20 or 30 min, allowing 0, 30 or 60 sec >100cpm) in 10-12 year old children. Estimates of sedentary time accumulated in bouts varied largely between the different bout definitions. Generally, children sat mostly in sedentary bouts of at least 5 min, while 20 min bouts were rare. For none of the operational definitions the authors found convincing evidence for a cross-sectional association with cardiometabolic health indicators in 10-12 year old children. However, more significant associations appeared when allowing no tolerance (i.e. zero sec >100cpm). Therefore, the authors recommend that no tolerance should be allowed within a sedentary bout.
Both papers emphasise the need for standardized definitions of sedentary bouts as well as a consensus regarding accelerometer data-reduction criteria to advance the field of sedentary behaviour and the potential associated health risk. Moreover, sedentary behaviour researchers cannot rely on accelerometer data reduction procedures established for assessing physical activity.
- Chinapaw MJM, Altenburg TM, Brug, J (2014). Sedentary behaviour and health in children – Evaluating the evidence. Prev Med 70: 1-2.
- Chinapaw MJM, de Niet M, Verloigne M, De Bourdeaudhuij I, Brug J, Altenburg TM (2014). From sedentary time to sedentary patterns: accelerometer data reduction decisions in youth. PLoS ONE 9(11): e111205. doi:10.1371/journal.pone.0111205.
- Altenburg TM, de Niet M, Verloigne M, De Bourdeaudhuij I, Androutsos O, Manios Y, Kovacs E, Bringolf-Isler B, Brug J, Chinapaw MJM (2015). Occurrence and duration of various operational definitions of sedentary bouts and cross-sectional associations with cardiometabolic health indicators: the ENERGY-project. Prev Med 71: 101-106.