Issues related to measuring and interpreting objectively measured sedentary behavior data

The use of objective measures of sedentary behavior has increased over the past decade; however, as is the case for objectively measured physical activity, methodological decisions before and after data collection are likely to influence the outcomes. The aim of this article is to review the evidence on different methodological decisions made by researchers when examining sedentary behavior. The different issues researchers may encounter when measuring sedentary behavior have been divided into (a) activity monitor placement; (b) epochs, cut points, and non-wear time definitions; (c) criteria for sedentary behavior bouts and breaks; and (d) combining motion and posture data. This article recommends that (a) activity monitors should be placed on the thigh and combined with a data reduction approach that estimates inclination, especially in children and adults; and (b) researchers should clearly report their data processing decisions to enhance the ability to evaluate and compare studies in the future. However, the article also highlights a dearth of methodological evidence to inform the use of objective measures of sedentary behavior. Based on the gaps in the literature, research recommendations, which require addressing to develop a best practice protocol when measuring sedentary behavior objectively, have been made

Impact assessment effectiveness in Otago Regional and District Councils

The Resource Management Act (RMA, 1991) has been in place for over 28 years. Section 88 of the RMA (1991) requires ‘impact assessment’, under the name ‘Assessment of Environmental Effects’ (AEE) in accordance with Schedule 4 of the Act. There is a requirement for all resource consents, large and small, to have an accompanying AEE. There are a wide range of different forms of AEE that arise from different authorship. From a mother and father wanting to build a garage to multimillion-dollar infrastructure projects, all require an AEE. The wide scale of AEE presents challenges for planners. What is an effective AEE at these different scales? This research looks to answer this question through the perspective of planners working in a range of councils in the Otago region of the South Island of New Zealand. Effectiveness, as a component of impact assessment, is of growing academic interest. Several theories of how to interpret effectiveness exist. The most prominent theory evaluates impact assessment in relation to Procedural, Substantive, Transactive and Normative effectiveness. Interviews with planners working in councils, to understand their views of effectiveness, were the primary sources of information for this research. Processing planners from the Otago Regional Council, Dunedin City Council, Waitaki District Council, and Clutha District Council were interviewed. Other sources of information include the National Monitoring System data, which collects data related to RMA matters from councils around New Zealand, and a case study. These sources of data supported one another and helped to provide a greater level of certainty in the results of the research. This research compared the results of interviews, NMS data, and the case study to Procedural, Substantive, Transactive and Normative effectiveness. In general, impact assessment was found to be procedurally, substantively, and transactively effective, though specific problems were mentioned, particularly with regard to normative effectiveness. Procedurally, AEE adequately assess environmental effects. Substantively, planners were aware of the objectives of the legislation and were able to achieve substantive effectiveness throughout the AEE assessment process. Tools, such as non-formal communication, enabled a high level of transactive effectiveness. Normative effectiveness was the least well-attested with respondents recognising that barriers existed preventing AEE from being normatively effective. A common theme in the literature is to develop a general framework and then adapt it to the specific local conditions. There are a range of categorisations of effectiveness. Each framework assesses achievement of impact assessment in each category. This research sought to adopt a framework for effectiveness in New Zealand. The research showed that substantive matters are the primary form of effectiveness in New Zealand. All other forms of effectiveness are subservient to substantive aims of the RMA. There is a close relationship between substantive, procedural and transactive effectiveness. Normative effectiveness was less well attested, though there was recognition of systematic barriers preventing normative effectiveness from becoming more prominent in New Zealand

Appropriateness of the definition of 'sedentary' in young children : whole-room calorimetry study

The present study aimed to measure the energy cost of three common sedentary activities in young children to test whether energy expended was consistent with the recent consensus definition of 'sedentary' as 'any behaviour conducted in a sitting or reclining posture and with an energy cost ≤1.5 metabolic equivalents (METs)' (Sedentary Behaviour Research Network, 2012).  This was an observational study

Practical utility and reliability of whole-room calorimetry in young children

The use of whole-room calorimetry (WRC) in young children can increase our understanding of children's energy balance. However, studies using WRC in young children are rare due to concerns about its feasibility. To assess the feasibility of WRC in young children, forty children, aged 4-6 years, were asked to follow a graded activity protocol while in a WRC. In addition, six children participated in two additional resting protocols to examine the effect of diet-induced thermogenesis on resting energy expenditure (REE) measures and the reliability of REE measurement. Refusals to participate and data loss were quantified as measures of practical utility, and REE measured after an overnight fast and after a 90-min fast were compared. In addition, both were compared to predicted BMR values using the Schofield equation. Our results showed that thirty (78·9 %) participants had acceptable data for all intensities of the activity protocol. The REE values measured after a 90-min fast (5·07 (sd 1·04) MJ/d) and an overnight fast (4·73 (sd 0·61) MJ/d) were not significantly different from each other (P = 0·472). However, both REE after an overnight fast and a 90-min fast were significantly higher than predicted BMR (3·96 (sd 0·18) MJ/d) using the Schofield equation (P = 0·024 and 0·042, respectively). We conclude that, with a developmentally sensitive approach, WRC is feasible and can be standardised adequately even in 4- to 6-year-old children. In addition, the effect of a small standardised breakfast, approximately 90 min before REE measurements, is likely to be small

Predictive validity and classification accuracy of actigraph energy expenditure equations and cut-points in young children

Objectives: Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers. Methods: Forty children aged 4–6 years (5.3±1.0 years) completed a ~150-min room calorimeter protocol involving age-appropriate sedentary, light and moderate-to vigorous-intensity physical activities. Children wore an ActiGraph GT3X on the right mid-axillary line of the hip. Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods. Energy expenditure was predicted using Pate and Puyau equations. Physical activity intensity was classified using Evenson, Sirard, Van Cauwenberghe, Pate, Puyau, and Reilly, ActiGraph cut-points. Results: The Pate equation significantly overestimated VO2 during sedentary behaviors, light physical activities and total VO2 (P<0.001). No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities (P = 0.072). The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities, light-intensity physical activities and total activity energy expenditure (P<0.0125). However, no overestimation of activity energy expenditure during sedentary behavior was found. The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others. Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others. Conclusion: Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers. Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities, respectively, are recommended

Associations between sports participation, adiposity and obesity-related health behaviors in Australian adolescents

Background The purpose of this study was to examine the relationship between organized sports participation, weight status, physical activity, screen time, and important food habits in a large nationally representative sample of Australian adolescents. Methods Nationally representative cross-sectional study of 12,188 adolescents from 238 secondary schools aged between 12 and 17 years (14.47 ± 1.25 y, 53% male, 23% overweight/obese). Participation in organized sports, compliance with national physical activity, screen time, and fruit and vegetable consumption guidelines, and consumption of sugar-sweetened beverages and high-fat foods were self-reported. Weight status and adiposity (BMI, waist circumference) were measured. Results Organized sports participation was higher among males and those residing in rural/remote areas. Underweight adolescents reported the lowest levels of participation. Higher levels of participation were associated with an increased likelihood of complying with national physical activity (OR = 2.07 [1.67-2.58]), screen time (OR = 1.48 [1.19-1.84]), and fruit and vegetable consumption guidelines (OR = 1.32 [1.05-1.67]). There was no association between organized sport participation and weight status, adiposity, consumption of sugar-sweetened beverages or high-fat foods. Conclusions Participation in organized sports was associated with a greater likelihood to engage in a cluster of health behaviors, including meeting physical activity guidelines, electronic screen time recommendations, and fruit and vegetable consumption guidelines. However, participation in organized sports was not associated with unhealthy dietary behaviors including the consumption of sugar-sweetened beverages and high-fat foods. There is no association between participation in organized sports and likelihood to be overweight or obese. The role of sports in promoting healthy weight and energy balance is unclear

Instructional strategies to promote incremental beliefs in youth sport

Implicit beliefs about the nature of human abilities have significant motivational, behavioral, and affective consequences. The purpose of this article was to review the application of implicit beliefs to the youth sport context and to provide theoretically derived and evidence-based instructional strategies to promote adaptive implicit beliefs about human abilities within this context. A narrative overview of theory and a review of research pertaining to implicit beliefs in education, sport, and physical activity are undertaken. Theoretically derived and evidence-based instructional strategies are outlined, and specific coaching behaviors are suggested. Six instructional strategies to promote adaptive implicit beliefs in these contexts are suggested: focusing on effort and persistence, facilitating challenge, promoting the value of failure, defining success as effort, the promotion of learning, and providing high expectations. It is concluded that instructional strategies may be used to facilitate positive motivational, behavioral, and affective outcomes for young people within a sport context

Reducing electronic media use in 2-3 year-old children: feasibility and efficacy of the Family@play pilot randomised controlled trial

BACKGROUND: Participation in electronic media use among 2-3 year olds is high and associated with adverse health and developmental outcomes. This study sought to test the feasibility and potential efficacy of a family-based program to decrease electronic media (EM) use in 2-3-year-old children. METHODS: Family@play was a six-session pilot randomised controlled trial delivered to parents of 2-3 year-old children from August to September 2012 in a community environment in the Illawarra region of New South Wales, Australia. Development of program content was guided by Social Cognitive and Family Systems Theories. The primary outcome was children\u27s electronic media use. Secondary outcomes included children\u27s time in sitting, standing and stepping. Data collectors were blinded to group allocation. Parents completed comprehensive process evaluation measures and participated in focus group discussions following completion of the program. Regression analyses were undertaken and effect sizes calculated using principles of intention to treat. RESULTS: Twenty-two participants (n&thinsp;=&thinsp;12 intervention; n&thinsp;=&thinsp;10 control) provided complete baseline data; complete data from 16 participants (n&thinsp;=&thinsp;6 intervention; n&thinsp;=&thinsp;10 control) were available post-intervention. Process evaluation results were high, showing the acceptability of the program. Compared with children in the control group, there were greater decreases in total EM use among children in the intervention group (adjusted difference [95 % CI]&thinsp;=&thinsp;-31.2 mins/day [-71.0-8.6] Cohen\u27s d&thinsp;=&thinsp;0.70). Differences for other outcomes were in the hypothesised direction and ranged from small for postural (sitting, standing, stepping) outcomes to moderate to large for individual electronic media (e.g. TV viewing, DVD/video viewing). CONCLUSIONS: This is the first family-based study to engage families of 2-3 year old children outside the United States and target multiple EM behaviours. Family@play was shown to be a feasible and acceptable intervention to deliver to families of 2-3 year old children. Potential efficacy is evident from moderate to large effect sizes. A larger trial is warranted to test the efficacy of the program. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( ACTRN12612000470897 )

Relationship between plantar pressures, physical activity and sedentariness among preschool children

It has been speculated that high plantar pressures might cause foot pain and discomfort which, in turn, may discourage children from being physically active and result in them spending more time in sedentary activities. The purpose of this study was to determine whether plantar pressure distributions generated by preschool children were correlated with objectively measured time spent in physical activity and sedentary behaviour. Dynamic plantar pressures were measured for 33 preschool children (age = 4.3±0.6 years; height = 1.06±0.1 m; mass = 18.4±2.9 kg; 17 boys) as they walked across an emed AT-4 pressure platform. Physical activity was objectively assessed using MT ActiGraph accelerometers. Total physical activity (counts per minute), percentage of time spent in moderate-to-vigorous physical activity (MVPA), light activity and sedentary behaviour were then calculated. Peak pressures across the heel were found to significantly correlate with total physical activity (r =−0.53; p = 0.03) and time in MVPA (r =−0.47; p = 0.05) in boys. Similarly, the correlation data suggested that girls who generated higher peak pressures in the toe region spent more time in sedentary behaviour (r = 0.53; p = 0.04). As high plantar pressures appear to be a potential negative correlate of physical activity and sedentary behaviour, it is recommended that further research be conducted to design, test and evaluate the potential of interventions to reduce plantar pressures in inactive children so they can enjoy the benefits associated with participating in a more active lifestyle