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

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

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

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 )

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

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

Effects of integrated physical exercises and gestures on preschool children’s foreign language vocabulary learning

Research suggests that integrating human movement into a cognitive learning task can be effective for learning due to its cognitive and physiological effects. In this study, the learning effects of enacting words through whole-body movements (i.e., physical exercise) and part-body movements (i.e., gestures) were investigated in a foreign language vocabulary task. Participants were 111 preschool children of 15 childcare centers, who were randomly assigned to one of four conditions. Participants had to learn 14 Italian words in a 4-week teaching program. They were tested on their memory for the words during, directly after, and 6 weeks after the program. In the integrated physical exercise condition, children enacted the actions indicated by the words to be learned in physical exercises. In the non-integrated physical exercise condition children performed physical exercises at the same intensity, but unrelated to the learning task. In the gesturing condition, children enacted the actions indicated by the words to be learned by gesturing while remaining seated. In the conventional condition, children verbally repeated the words while remaining seated. Results confirmed the main hypothesis, indicating that children in the integrated physical exercise condition achieved the highest learning outcomes. Implications of integrated physical exercise programs for preschool children’s cognition and health are discussed

Energy cost of physical activities and sedentary behaviors in young children

Background: This study reports energy expenditure (EE) data for lifestyle and ambulatory activities in young children. Methods: Eleven children aged 3 to 6 years (mean age = 4.8 ± 0.9; 55% boys) completed 12 semistructured activities including sedentary behaviors (SB), light (LPA), and moderate-to-vigorous physical activities (MVPA) over 2 laboratory visits while wearing a portable metabolic system to measure EE. Results: Mean EE values for SB (TV, reading, tablet and toy play) were between 0.9 to 1.1 kcal/min. Standing art had an energy cost that was 1.5 times that of SB (mean = 1.4 kcal/min), whereas bike riding (mean = 2.5 kcal/min) was similar to LPA (cleaning-up, treasure hunt and walking) (mean = 2.3 to 2.5 kcal/min), which had EE that were 2.5 times SB. EE for MVPA (running, active games and obstacle course) was 4.2 times SB (mean = 3.8 to 3.9 kcal/ min). Conclusion: EE values reported in this study can contribute to the limited available data on the energy cost of lifestyle and ambulatory activities in young children