Worldwide consensus on the terminology that supports research into sedentary behavior

A worldwide network of scientists examining the links between sedentary lifestyles and health problems such as obesity and cardiovascular disease today announced a new dictionary of terms to support research into sedentary behaviour.

18 jun 2017--The results of the 'terminology consensus project' led by the Children's Hospital of Eastern Ontario Research Institute's (CHEO RI) Sedentary Behaviour Research Network (SBRN) are published today in the International Journal of Behavioral Nutrition and Physical Activity in a paper co-authored by 84 scientists from 20 countries.
"This is the world's most extensive agreement to date on consensus definitions for researchers examining sedentary behaviour, an emerging global public health priority," said lead author Dr. Mark Tremblay, director of the CHEO RI's Healthy Active Living and Obesity Research Group (HALO) and a professor at the University of Ottawa. "There is an urgent need for clear, common and accepted terminology worldwide to facilitate the interpretation and comparison of research. We have made tremendous progress by defining terms such as physical inactivity, stationary behaviour, sedentary behaviour, and screen time. These terms have already been translated into several languages for rapid global uptake."
The paper, entitled "Sedentary Behaviour Research Network: Terminology Consensus Project Process and Outcome", provides refined definitions to suit all age groups, including babies, young children and people with chronic disease or mobility impairment. It also describes how bouts, breaks and interruptions should be defined and measured in the context of assessing sedentary behaviour and in relation to health outcomes.
The conceptual framework described in the paper also illustrates how both energy expenditure and posture are important components and how the terms relate to movement behaviours throughout a 24-hour period, including physical activity and sleep. Examples provided distinguish between active and passive sitting, active and passive standing, sedentary and stationary behaviour, screen time and non-screen-based sedentary time. Sedentary behaviour for a baby, for example, includes sitting in a car seat with minimal movement and, for a toddler, watching TV while sitting, reclining or lying down.
The 84 SBRN co-authors, which include researchers, trainees, graduate students, health practitioners and government employees, agree that standardization of the terminology is crucial to advancing future research, especially since this rapidly growing field of health science involves multi-disciplinary researchers, practitioners and industries.
"These consensus definitions will help scientists and practitioners navigate and understand the rapidly evolving field of sedentary behaviour research, allowing for more consistent and robust exploration of behaviours across 24 hours - sleep, sedentary behaviours and various intensities of physical activity - and may facilitate future research exploring ways to alter behaviours to improve health," Dr. Tremblay said. "Our hope is that these will reduce confusion and advance research related to sedentary behaviour and, ultimately, promote healthy active living."
Dr. Tremblay will chair a discussion of the project's findings at a workshop today at the International Society of Behavioral Nutrition and Physical Activity annual meeting in Victoria, British Columbia. Consensus definitions have been translated into French, Spanish, Portuguese, Dutch, Korean, German, Greek, Traditional Chinese, and Japanese.


Provided by Children's Hospital of Eastern Ontario Research Institute

A Little Brisk Walking Gives Benefits to the Sedentary

BELFAST, Ireland, Aug. 14 -- Sedentary adults who took a brisk half-hour walk on only three days a week lost weight and were rewarded with improved fitness and cardiovascular benefits, researchers reported.
The three-day walking program produced a significant reduction in systolic blood pressure, weight, and an increase in functional capacity after 12 weeks, Mark A. Tully, Ph.D., of Queen's University in Belfast, and colleagues, reported in the Journal of Epidemiology and Community Health.
Few meet the current minimum exercise recommendation of 30 minutes of exercise five days a week, citing lack of time, the investigators noted. But the unsupervised three-month home-based program of brisk walking for 30 minutes three days a week demonstrated that less may be better than nothing.
Those who walked five days a week, the current recommended level, improved in these measures as well, and also had a decrease in diastolic blood pressure, the researchers reported.
To determine the short-term effects of walking at and below the current recommended exercise levels, the researchers randomized 106 healthy, sedentary men and women, ages 40 to 61, to a three-month walking program.
There were 44 participants taking a brisk walk for 30 minutes three days a week, 42 doing so five days a week, and 20 in a sedentary control group.
Participants could choose to walk in bouts of at least 10 minutes, and used pedometers to record the number of steps taken.
Blood samples were analyzed for lipid levels, while waist and hip circumferences were measured with standard procedures.
Functional capacity was measured by a 10-meter shuttle walk test. Participants walked between two cones in response to a series of beeps of increasing frequency until they could no longer achieve the pace set.
Of the 106 participants, 93 completed the study, the researchers wrote.
Systolic blood pressure and waist and hip circumferences fell significantly both in the three-day group (5 mm Hg, 2.6 cm, and 2.4 cm, respectively) and in the five day group (6 mm Hg, 2.5 cm, and 2.2 cm) (P<0.05).
Weight (-0.97 kg) and BMI (-0.32 kg/m2) also decreased for the three-day walkers but, strangely, not for the five-day walkers.
Total cholesterol-to-HDL ratio also decreased significantly in the three-day group, although at baseline, these individuals had a larger waist circumference and a higher total cholesterol-HDL ratio.
Unlike three-day walkers, five-day walkers also recorded a decrease in diastolic blood pressure of 3.4 mm Hg (P<0.05).
Functional capacity, a substitute measure for fitness, increased in both groups (15%; 11%).
Finally, no changes occurred in the non-walking control group, the researchers reported.
To determine whether the significant changes in weight and BMI seen in the three-day group, but not in the five-day group, were a result of sex imbalance within the groups, the researchers did an analysis and found no significant differences.
Analysis of the food frequency diaries also showed no changes in any of the groups. Future studies, the researchers said, might use stratification by sex to avoid potential confounding effects.
Also, no significant changes in waist-hip ratios, associated with a risk of myocardial infarction, were found, possibly because of lack of powering in an insufficient sample size.
The reductions in systolic and diastolic blood pressure in the five-day group are similar to those reported in a meta-analysis of 16 studies, the researchers wrote.
The findings from this study, they added, indicate that the reduction in systolic blood pressure (6 mm Hg in the five-day group, and 4.5 mm Hg in the three-day group) are in themselves clinically significant in reducing the risk of vascular mortality.
Study limitations included the fact that walking was self-reported and the pace was self-selected. It was also possible that the three-day group did more exercise than they reported as the study design did not include an objective measure of all activity undertaken during the study, and this would require further exploration.
The walkers' motivation to demonstrate improvement may also have influenced their performance, the researchers said.
The results of this study may encourage people who feel they do not have time to exercise five days a week to consider a lower weekly target of exercise, or of taking an opportunity for short bouts of physical activity.
Further studies are needed of the longer effects of low levels of exercise and of unsupervised home-based walking for a wider community and should be large enough to allow detection of meaningful changes in a spectrum of cardiovascular risk factors, the researcher wrote.
No financial conflicts were reported. Dr. Tully was supported by funding from the Department of Education and Learning NI.Primary source: Journal of Epidemiology and Community HealthSource reference: Tully MA, et al "Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults" J Epidemiol Community Health 2007; 61:778-783.