Changes in Physical Activity Behaviour and Psychosocial Correlates Unique to the Transition from Primary to Secondary Schooling in Adolescent Females: A Longitudinal Cohort Study.

Few studies have investigated physical activity changes over the transition from primary to secondary school. This study assessed change in physical activity and the psychosocial correlates across 12 months in two cohorts of adolescent girls, who were either in primary school in year 1, moving to secondary school in year 2 (Transition cohort) or an older cohort (Secondary cohort) who remained in early secondary school. Female adolescents (n = 191; 38% response rate) in South Australia self-reported physical activity and psychosocial correlates of physical activity. Changes between baseline and 12-month follow-up were assessed using paired t-tests. Multiple regression modelling identified psychosocial predictors of physical activity change. Physical activity declined in the transition but not the secondary cohort. The decline was most pronounced during school break times. Independent predictors of physical activity change were: change in enjoyment in the transition cohort; and changes in enjoyment, perceived outcomes, and friend encouragement in the secondary cohort. Transitioning from primary to secondary school is a critical period during which physical activity typically declines, particularly among females. Effective physical activity promotion in this vulnerable group will depend on a deeper understanding of the sociocultural, curricular and environmental influences on physical activity that are unique to each school context.

A source of systematic bias in self-reported physical activity: The cutpoint bias hypothesis.

OBJECTIVES: Estimates of adults' moderate-to-vigorous physical activity (MVPA) based on self-report are generally higher than estimates derived from criterion measures. This study examines a possible explanation for part of this discrepancy: the cutpoint bias hypothesis. This hypothesis proposes that inter- and intra-individual variability in energy expenditure, combined with the fact that adults perform a high proportion of daily activities at or just above the traditional 3 MET cutpoint, result in systematic over-estimates of MVPA. DESIGN: Cross-sectional. METHODS: Time-use recalls (n = 6862) were collected using the Multimedia Activity Recall for Children and Adults from 2210 adults (1215 female, age 16-93 years) from 16 studies conducted in Australia and New Zealand between 2008-2017. Minutes spent in MVPA were estimated using models with varying levels of intra- and inter-individual (total variability) Unadjusted (0% total variability), Low (11.9%), Best Guess (20.7%), and High (30.0%). RESULTS: In the Unadjusted model, participants accumulated an average of 129 (standard deviation 127) min/day of MVPA. Estimated MVPA was 98 (110), 99 (107) and 108 (107) min/day in the Low, Best Guess and High variability models, respectively, with intra-class correlation coefficients with the Unadjusted model ranging from 0.78 to 0.83. CONCLUSIONS: These findings support the hypothesis of a cutpoint bias, which probably contributes to the large disparities seen between self-reported and criterion measures of MVPA. Future studies are needed to confirm these findings using other self-report instruments and in other populations.

Utility of the Youth Compendium of Physical Activities.

PURPOSE: The purposes of this article are to: (a) describe the rationale and development of the Youth Compendium of Physical Activities (Youth Compendium); and (b) discuss the utility of the Youth Compendium for audiences in research, education, community, health care, public health, and the private sector. METHODS: The Youth Compendium provides a list of 196 physical activities (PA) categorized by activity types, specific activities, and metabolic costs (youth metabolic equivalents of task [METy]) as measured by indirect calorimetry. The utility of the Youth Compendium was assessed by describing ways in which it can be used by a variety of audiences. RESULTS: Researchers can use METy values to estimate PA levels and determine changes in PA in intervention studies. Educators can ask students to complete PA records to determine time spent in physical activities and to identify health-enhancing activities for classroom PA breaks. Community leaders, parents, and health care professionals can identify activity types that promote healthful behaviors. Public health agencies can use the METy values for surveillance and as a resource to inform progress toward meeting national physical activity guidelines. Applications for the private sector include the use of METy in PA trackers and other applications. CONCLUSION: The National Collaborative on Childhood Obesity Research Web site presents the Youth Compendium and related materials to facilitate measurement of the energy cost of nearly 200 physical activities in children and youth. The Youth Compendium provides a way to standardize energy costs in children and youth and has application for a wide variety of audiences.

Children's physical activity levels during organised sports practices.

OBJECTIVES: This study measured the physical activity levels of children during practice sessions of four popular organised sports in Australia. DESIGN: Cross-sectional observational design. METHODS: Participants comprised children from four local organised sports clubs in suburban Adelaide, South Australia. The sports examined were Australian Rules Football (AFL), girls' netball, boys' soccer and girls' soccer. Each participant wore a waist-mounted GT3X or GT3X+Actigraph accelerometer in either one or two of the practice sessions. RESULTS: Participants typically spent 40-50% of each sport practice session in moderate to vigorous physical activity (MVPA). Participants in the boys' soccer teams spent significantly greater time in MVPA (mean=47% of practice time, 95% CI=37%, 57%) than participants in the girls' netball teams (mean=40%, 95% CI=30%, 50%), participants in the girls' soccer teams (mean=38%, 95% CI=28%, 48%) and participants in the boys' AFL teams (mean=40%, 95% CI=36%, 44%). The practice sessions contributed approximately half of the 60min of MVPA per day recommended by physical activity guidelines for children and young people. CONCLUSIONS: The results suggested that organised sports provide a supportive environment for physical activity accrual; however, one practice session is insufficient for children to reach the amount of MVPA recommended in daily physical activity guidelines.

A Youth Compendium of Physical Activities: Activity Codes and Metabolic Intensities.

PURPOSE: A Youth Compendium of Physical Activities (Youth Compendium) was developed to estimate the energy costs of physical activities using data on youth only. METHODS: On the basis of a literature search and pooled data of energy expenditure measurements in youth, the energy costs of 196 activities were compiled in 16 activity categories to form a Youth Compendium of Physical Activities. To estimate the intensity of each activity, measured oxygen consumption (V˙O2) was divided by basal metabolic rate (Schofield age-, sex-, and mass-specific equations) to produce a youth MET (METy). A mixed linear model was developed for each activity category to impute missing values for age ranges with no observations for a specific activity. RESULTS: This Youth Compendium consists of METy values for 196 specific activities classified into 16 major categories for four age-groups, 6-9, 10-12, 13-15, and 16-18 yr. METy values in this Youth Compendium were measured (51%) or imputed (49%) from youth data. CONCLUSION: This Youth Compendium of Physical Activities uses pediatric data exclusively, addresses the age dependency of METy, and imputes missing METy values and thus represents advancement in physical activity research and practice. This Youth Compendium will be a valuable resource for stakeholders interested in evaluating interventions, programs, and policies designed to assess and encourage physical activity in youth.

Criterion validity of the activPAL™ and ActiGraph for assessing children's sitting and standing time in a school classroom setting.

BACKGROUND: Few studies have investigated the accuracy of the ActiGraph (AG) GTX3 accelerometer for assessing children's sitting and standing time. The activPAL (aP) has an inclinometer function that enables it to distinguish between sitting/lying and standing; however, its accuracy for assessing sitting and standing in older children is unknown. This study validated the accuracy of these devices for estimating sitting and standing time in a school classroom against a criterion measure of direct observation (DO). FINDINGS: Forty children in grades 5-7 wore both devices while being video recorded during two school lessons. AG and aP data were simultaneously collected in 15-s epochs. Individual participant DO and aP data were recorded as total time spent sitting/lying, standing and stepping. AG data were converted into time spent sitting and standing using previously established cut-points. Compared with DO, the aP underestimated sitting time (mean bias = -1.9 min, 95 % LoA = -8.9 to 5.2 min) and overestimated standing time (mean bias = 1.8 min, 95% LoA = -9.6 to 13.3 min). The best-performing AG cut-point across both sitting and standing (<75 counts/15 s) was more accurate than the aP, underestimating sitting time (mean bias = -0.8 min, 95 % LoA = -10.5 to 9.9 min) and standing time (mean bias = -0.4 min, 95% LoA = -9.8 to 9.1 min), but was less precise as evidenced by wider LoAs and poorer correlations with DO (sitting r = 0.86 aP vs 0.80 AG; standing r = 0.78 aP vs 0.60 AG). CONCLUSIONS: The aP demonstrated good accuracy and precision for assessing free-living sitting and standing time in classroom settings. The AG was most accurate using a cut-point of < 75 counts/15 s. Further studies should validate the monitors in settings with greater inter- and intra-individual variation in movement patterns.

Energy Cost of Free-Play Activities in 10- to 11-Year-Old Children.

OBJECTIVE: This study sought to ascertain the energy expenditure (EE) associated with different sedentary and physically active free-play activities in primary school-aged children. METHODS: Twenty-eight children (13 boys; 11.4 ± 0.3 years; 1.45 ± 0.09 m; 20.0 ± 4.7 kg∙m-2) from 1 primary school in Northwest England engaged in 6 activities representative of children's play for 10 minutes (drawing, watching a DVD, playground games and free-choice) and 5 minutes (self-paced walking and jogging), with 5 minutes rest between each activity. Gas exchange variables were measured throughout. Resting energy expenditure was measured during 15 minutes of supine rest. RESULTS: Child (Schofield-predicted) MET values for watching a DVD, self-paced jogging and playing reaction ball were significantly higher for girls (P < .05). CONCLUSION: Utilizing a field-based protocol to examine children's free-living behaviors, these data contribute to the scarcity of information concerning children's EE during play to update the Compendium of Energy Expenditures for Youth.

The Energy Cost of Household Chores, Rollerblading, and Riding Scooters in 9- to 14-Year-Old Children.

BACKGROUND: To improve the scope of the Youth Compendium of Energy Expenditures, a range of everyday activities of varying intensity should be measured. This study measures the energy cost of children undertaking common household chores, rollerblading and riding a foot-propelled scooter. METHODS: Participants were 9- to 14-year-old children. A metabolic cart was used to measure oxygen cost (VO2) of a variety of household chores. A Cosmed K4b2 portable oxygen analyzer was used to measure VO2 during rollerblading and riding a scooter at self-selected speeds. Energy costs for each participant were calculated as child METs. RESULTS: Mean child MET costs for the household chores ranged from 1.3 to 3.6 METs. Rollerblading and riding a scooter yielded mean child MET costs of 6.5 and 6.3 METs respectively. CONCLUSIONS: Household chores were found to be of light to moderate intensity, while rollerblading and riding a scooter were vigorous activities.

Physical activity and sedentary behaviour among Asian and Anglo-Australian adolescents.

ISSUE ADDRESSED: Evidence suggests that physical activity (PA) and sedentary behaviour (SB) participation varies among culturally and linguistically diverse (CALD) adolescents. The present study examined differences in PA and SB among a CALD sample of Chinese Australian, South-east Asian and Anglo-Australian adolescents. METHODS: Data from 286 adolescents aged 12-16 years involved in the Chinese and Australian Adolescent Health Survey in metropolitan Melbourne, Australia, were analysed. Accelerometry outcomes included median activity counts per minute (counts x min(-1)) and minutes per day (min x day(-1)) spent in light-intensity PA (LPA), moderate-to-vigorous-intensity PA (MVPA) and sedentary time (ST). Kruskal-Wallis one-way analysis of variance and sequential multiple hierarchical linear regressions were used to examine CALD differences in PA and ST. RESULTS: Multivariate analyses of accelerometry data found Chinese Australian and South-east Asian adolescents engaged in significantly less daily MVPA (5-8 min x day(-1)) and LPA (50-58 min x day(-1); P < 0.05), but greater daily ST (40-41 min x day(-1)), than Anglo-Australian adolescents, after adjusting for age, gender and socioeconomic category. CONCLUSION: The results demonstrate lower engagement in daily MVPA and LPA and greater engagement in ST using accelerometry among Chinese Australian and South-east Asian adolescents compared with Anglo-Australian adolescents. These findings have important public health implications in furthering our understanding of CALD differences in PA and SB. SO WHAT? An understanding of the CALD differences in physical activity and sedentary behaviour among Australian adolescents has important implications for intervention planning and delivery as well as the wider health implications of these behaviours. This article furthers the current understanding of CALD adolescents' participation in physical activity and sedentary behaviour, of which limited information is available.

Development and psychometric properties of the Y-PASS questionnaire to assess correlates of lunchtime and after-school physical activity in children.

BACKGROUND: To frame interventions, it is useful to understand context- and time-specific correlates of children's physical activity. To do this, we need accurate assessment of these correlates. There are currently no measures that assess correlates at all levels of the social ecological model, contain items that are specifically worded for the lunchtime and/or after-school time periods, and assess correlates that have been conceptualised and defined by children. The aim of this study was to develop and evaluate the psychometric properties of the lunchtime and after-school Youth Physical Activity Survey for Specific Settings (Y-PASS) questionnaires. METHODS: The Y-PASS questionnaire was administered to 264 South Australian children (146 boys, 118 girls; mean age = 11.7 ± 0.93 years). Factorial structure and internal consistency of the intrapersonal, sociocultural and physical environmental/policy lunchtime and after-school subscales were examined through an exploratory factor analysis. The test-retest reliability of the Y-PASS subscales was assessed over a one-week period on a subsample of children (lunchtime Y-PASS: n = 12 boys, 12 girls, mean age of 11.6 ± 0.8 years; after-school Y-PASS: n = 9 boys, 13 girls; mean age = 11.4 ± 0.9 years). RESULTS: For the lunchtime Y-PASS, three factors were identified under each of the intrapersonal, sociocultural and physical environmental/policy subscales. For the after-school Y-PASS, six factors were identified in the intrapersonal subscale, four factors in the sociocultural subscale and seven factors in the physical environmental/policy subscale. Following item reduction, all subscales demonstrated acceptable internal consistency (Cronbach alpha = 0.78-0.85), except for the lunchtime sociocultural subscale (Cronbach alpha = 0.55). The factors and items demonstrated fair to very high test-retest reliability (ICC = 0.26-0.93). CONCLUSION: The preliminary reliability and factorial structure evidence suggests the Y-PASS correlate questionnaires are robust tools for measuring correlates of context-specific physical activity in children. The multi-dimensional factor structure provides justification for exploring physical activity correlates from a social ecological perspective and demonstrates the importance of developing items that are context specific. Further development and refinement of the Y-PASS questionnaires is recommended, including a confirmatory factor analysis and exploring the inclusion of additional items.

Increasing specificity of correlate research: exploring correlates of children's lunchtime and after-school physical activity.

BACKGROUND: The lunchtime and after-school contexts are critical windows in a school day for children to be physically active. While numerous studies have investigated correlates of children's habitual physical activity, few have explored correlates of physical activity occurring at lunchtime and after-school from a social-ecological perspective. Exploring correlates that influence physical activity occurring in specific contexts can potentially improve the prediction and understanding of physical activity. Using a context-specific approach, this study investigated correlates of children's lunchtime and after-school physical activity. METHODS: Cross-sectional data were collected from 423 South Australian children aged 10.0-13.9 years (200 boys; 223 girls) attending 10 different schools. Lunchtime and after-school physical activity was assessed using accelerometers. Correlates were assessed using purposely developed context-specific questionnaires. Correlated Component Regression analysis was conducted to derive correlates of context-specific physical activity and determine the variance explained by prediction equations. RESULTS: The model of boys' lunchtime physical activity contained 6 correlates and explained 25% of the variance. For girls, the model explained 17% variance from 9 correlates. Enjoyment of walking during lunchtime was the strongest correlate for both boys and girls. Boys' and girls' after-school physical activity models explained 20% variance from 14 correlates and 7% variance from the single item correlate, "I do an organised sport or activity after-school because it gets you fit", respectively. CONCLUSIONS: Increasing specificity of correlate research has enabled the identification of unique features of, and a more in-depth interpretation of, lunchtime and after-school physical activity behaviour and is a potential strategy for advancing the physical activity correlate research field. The findings of this study could be used to inform and tailor gender-specific public health messages and interventions for promoting lunchtime and after-school physical activity in children.

Reliability and validity of the modified Child and Adolescent Physical Activity and Nutrition Survey (CAPANS-C) questionnaire examining potential correlates of physical activity participation among Chinese-Australian youth.

BACKGROUND: To date, few questionnaires examining psychosocial influences of physical activity (PA) participation have been psychometrically tested among Culturally and Linguistically Diverse (CALD) youth. An understanding of these influences may help explain the observed differences in PA among CALD youth. Therefore, this study examined the reliability and predictive validity of a brief self-report questionnaire examining potential psychological and social correlates of physical activity among a sample of Chinese-Australian youth. METHODS: Two Chinese-weekend cultural schools from eastern metropolitan Melbourne consented to participate in this study. In total, 505 students aged 11 to 16 years were eligible for inclusion in the present study, and of these, 106 students agreed to participate (21% response rate). Participants completed at 37-item self-report questionnaire examining perceived psychological and social influences on physical activity participation twice, with a test-retest interval of 7 days. Predictive validity, internal consistency and test-retest reliability were evaluated using exploratory factor analyses, Cronbach's α coefficient, and the intraclass correlation coefficient (ICC) respectively. Predictive validity was assessed by correlating responses against duration spent in self-reported moderate-to-vigorous physical activity (MVPA). RESULTS: The exploratory factor analysis revealed a nine factor structure, with the majority of factors exhibiting high internal consistency (α ≥ 0.6). In addition, four of the nine factors had an ICC ≥ 0.6. Spearman rank-order correlations coefficients between the nine factors and self-reported minutes spent in MVPA ranged from -0.5 to 0.3 for all participants. CONCLUSION: This is the first study to examine the psychometric properties of a potential psychological and social correlates questionnaire among Chinese-Australian youth. The questionnaire was found to provide reliable estimates on a range of psychological and social influences on physical activity and evidence of predictive validity on a limited number of factors. More research is required to improve the reliability and validity of the questionnaire.

Validating the multimedia activity recall for children and adolescents in a large New Zealand sample.

The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10-18 years) recalled 3-4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate-vigorous physical activity. Association and agreement between methods for light physical activity and moderate-vigorous physical activity was assessed using correlations and Bland-Altman plots respectively, and paired t-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38, P < 0.0001). The correlation between methods was -0.14 for light physical activity and 0.28 for moderate-vigorous physical activity (P < 0.0001). The MARCA overestimated moderate-vigorous physical activity compared with accelerometry (120 min, P < 0.0001), which increased as moderate-vigorous physical activity time increased. Some sex and ethnicity (Maori [indigenous] versus non-Maori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate-vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research.

Presleep activities and time of sleep onset in children.

OBJECTIVE: Presleep activities have been implicated in the declining sleep duration of young people. A use-of-time approach may be used to describe the presleep period. The study aims were to describe the activities undertaken 90 minutes before sleep onset and to examine the association between activities and time of sleep onset in New Zealand young people. METHODS: Participants (N = 2017; 5-18 years) self-reported their time use as part of a national survey. All activities reported in the 90 minutes before sleep were extracted. The top 20 activities were grouped into 3 behavioral sets: screen sedentary time, nonscreen sedentary time, and self-care. An adjusted regression model was used to estimate presleep time spent in each behavioral set for 4 distinct categories of sleep onset (very early, early, late, or very late), and the differences between sleep onset categories were tested. RESULTS: In the entire sample, television watching was the most commonly reported activity, and screen sedentary time accounted for ∼30 minutes of the 90-minute presleep period. Participants with a later sleep onset had significantly greater engagement in screen time than those with an earlier sleep onset. Conversely, those with an earlier sleep onset spent significantly greater time in nonscreen sedentary activities and self-care. CONCLUSIONS: Screen sedentary time dominated the presleep period in this sample and was associated with a later sleep onset. The development of interventions to reduce screen-based behaviors in the presleep period may promote earlier sleep onset and ultimately improved sleep duration in young people.

Doubly labeled water validation of a computerized use-of-time recall in active young people.

OBJECTIVE: Low levels of daily energy expenditure (insufficient physical activity and increased sedentary time) have been associated with adverse health outcomes in young people. The Multimedia Activity Recall for Children and Adolescents (MARCA) is a computerized, self-report, use-of-time tool that can assess daily energy expenditure. The study aim was to validate the MARCA for the estimation of energy expenditure in young people, using the criterion standard doubly labeled water. MATERIALS/METHODS: Over a 15 day assessment period, 32 participants (10-18 years) completed the MARCA and underwent a doubly labeled water protocol. Indirect calorimetry was used to assess resting metabolic rate. Total daily energy expenditure (TEE) and activity-related energy expenditure (AEE) were estimated from both the MARCA and doubly labeled water. Association and agreement between methods for TEE and AEE were assessed using Spearman correlations and Bland-Altman plots, respectively. RESULTS: Compared to doubly labeled water, the MARCA over-estimated TEE by an average of 50 kcal/day (limits of agreement -1 589 to 1 490 kcal/day) and under-estimated AEE 105 kcal/day (limits of agreement -1 404 to 1 614 kcal/day). The MARCA showed strong correlation with doubly labeled water for TEE (rho=0.70, p<0.0001) and moderate correlation for AEE (rho=0.56, p=0.0009). CONCLUSIONS: Overall, the MARCA indicated moderate validity for the assessment of daily TEE and AEE. The wide limits of agreement indicate the MARCA has greater utility for group-level rather than individual-level estimates.

Correlates of children's time-specific physical activity: a review of the literature.

Assessment of correlates of physical activity occurring at different times of the day, locations and contexts, is imperative to understanding children's physical activity behaviour. The purpose of this review was to identify the correlates of children's physical activity (aged 8-14 years) occurring during the school break time and after-school periods. A review was conducted of the peer-reviewed literature, published between 1990 and January 2011. A total of 22 studies (12 school break time studies, 10 after-school studies) were included in the review. Across the 22 studies, 17 studies were cross-sectional and five studies were interventions. In the school break time studies, 39 potential correlates were identified, of which gender and age were consistently associated with school break time physical activity in two or more studies, and family affluence, access to a gym, access to four or more physical activity programs and the condition of a playing field were all associated with school break time physical activity in only one study. Access to loose and fixed equipment, playground markings, size of and access to play space and the length of school break time were all positively associated with changes in school break time physical activity in intervention studies. Thirty-six potential correlates of after-school physical activity were identified. Gender (with boys more active), younger age, lower body mass index (for females), lower TV viewing/playing video games, and greater access to facilities were associated with higher levels of after-school physical activity in two or more studies. Parent supervision was negatively associated with females' after-school physical activity in one study. This review has revealed a relatively small number of studies investigating the school break time and after-school periods in the specified age range and only a few correlates have demonstrated a consistent association with physical activity. This highlights the infancy of this area and a need for further investigation into time-specific physical activity behaviour so that interventions designed for these specific periods can target the important correlates.

Agreement between activPAL and ActiGraph for assessing children's sedentary time.

BACKGROUND: Accelerometers have been used to determine the amount of time that children spend sedentary. However, as time spent sitting may be detrimental to health, research is needed to examine whether accelerometer sedentary cut-points reflect the amount of time children spend sitting. The aim of this study was to: a) examine agreement between ActiGraph (AG) cut-points for sedentary time and objectively-assessed periods of free-living sitting and sitting plus standing time using the activPAL (aP); and b) identify cut-points to determine time spent sitting and sitting plus standing. METHODS: Forty-eight children (54% boys) aged 8-12 years wore a waist-mounted AG and thigh-mounted aP for two consecutive school days (9-3:30 pm). AG data were analyzed using 17 cut-points between 50-850 counts·min-1 in 50 counts·min-1 increments to determine sedentary time during class-time, break time and school hours. Sitting and sitting plus standing time were obtained from the aP for these periods. Limits of agreement were computed to evaluate bias between AG50 to AG850 sedentary time and sitting and sitting plus standing time. Receiver Operator Characteristic (ROC) analyses identified AG cut-points that maximized sensitivity and specificity for sitting and sitting plus standing time. RESULTS: The smallest mean bias between aP sitting time and AG sedentary time was AG150 for class time (3.8 minutes), AG50 for break time (-0.8 minutes), and AG100 for school hours (-5.2 minutes). For sitting plus standing time, the smallest bias was observed for AG850. ROC analyses revealed an optimal cut-point of 96 counts·min-1 (AUC = 0.75) for sitting time, which had acceptable sensitivity (71.7%) and specificity (67.8%). No optimal cut-point was obtained for sitting plus standing (AUC = 0.51). CONCLUSIONS: Estimates of free-living sitting time in children during school hours can be obtained using an AG cut-point of 100 counts·min-1. Higher sedentary cut-points may capture both sitting and standing time.

Physical activity and screen time behaviour in metropolitan, regional and rural adolescents: a -sectional study of Australians aged 9-16 years.

OBJECTIVES: While there is consistent evidence that rural adults in Australia are less active than their urban counterparts, studies relating geographical remoteness to activity patterns in Australian adolescents have yielded inconsistent results. The aim of this study was to describe objectively and subjectively measured patterns of physical activity and sedentary behaviours across remoteness categories in a representative sample of 9-16 year old Australians. DESIGN: Cross-sectional observational study. METHODS: 2071 Australian adolescents provided self-report use of time data on four days and wore a pedometer for at least 6 days within the 2007 Australian National Children's Nutrition and Physical Activity Survey. Comparisons of activity patterns were made across four objectively-determined remoteness categories (Major City, Inner Regional, Outer Regional and Remote), adjusting for household income, parental education and age. RESULTS: Adolescents living in major cities self-reported 11-29 min less moderate to vigorous physical activity each day than their counterparts living in geographically more remote areas, and took 150-850 fewer steps each day. While there were no differences in time spent in sport or active transport, differences in free play participation were significant. Males in major cities also reported higher levels of screen time. Differences were somewhat more marked among males than among females. CONCLUSIONS: Activity levels among Australian adolescents show contrasting patterns of geographical differences to those found in Australian adults. Higher levels of free play among rural Australian adolescents may be due to more available space and less fear of traffic and stranger risks.

It's not just the television: survey analysis of sedentary behaviour in New Zealand young people.

BACKGROUND: Sedentary behaviour has been linked with adverse health outcomes in young people; however, the nature and context of being sedentary is poorly understood. Accurate quantification and description of sedentary behaviour using population-level data is required. The aim of this research was to describe sedentary behaviour among New Zealand (NZ) youth and examine whether sedentary behaviour differs by Body Mass Index (BMI) status in this population. METHODS: A national representative cross-sectional survey of young people aged 5-24 years (n = 2,503) was conducted in 2008-2009. Data from this survey, which included subjectively (recall diary; n = 1,309) and objectively (accelerometry; n = 960) measured sedentary behaviour for participants aged 10-18 years were analysed using survey weighted methods. RESULTS: Participants self-reported spending on average 521 minutes per day (standard error [SE] 5.29) in total sedentary behaviour, 181 minutes per day (SE 3.91) in screen-based sedentary activities (e.g., television and video games), and 340 minutes per day (SE 5.22) in other non-screen sedentary behaviours (e.g., school, passive transport and self-care). Accelerometer-measured total sedentary behaviour was on average 420 minutes per day (SE 4.26), or 53% (SE 0.42%) of monitored time. There were no statistically significant differences in time spent in sedentary behaviour among overweight, obese and healthy/underweight young people. CONCLUSIONS: Both subjective and objective methods indicate that NZ youth spend much of their waking time being sedentary. No relationships were found between sedentary behaviour and BMI status. These findings extend previous research by describing engagement in specific sedentary activities, as well as quantifying the behaviour using an objective method. Differences in what aspects of sedentary behaviour the two methods are capturing are discussed. This research highlights the potential for future interventions to target specific sedentary behaviours or demographic groups.

Reliability of the modified child and adolescent physical activity and nutrition survey, physical activity (CAPANS-PA) questionnaire among Chinese-Australian youth.

BACKGROUND: Evidence suggests that differences exist in physical activity (PA) participation among Culturally and Linguistically Diverse (CALD) children and adolescents. It is possible that these differences could be influenced by variations in measurement technique and instrument reliability. However, culturally sensitive instruments for examining PA behaviour among CALD populations are lacking. This study tested the reliability of the Child and Adolescent Physical Activity and Nutrition Survey (CAPANS-PA) recall questionnaire among a sample of Chinese-Australian youth. METHODS: The psychometric property of the CAPANS-PA questionnaire was examined among a sample of 77 Chinese-Australian youth (aged 11-14 y) who completed the questionnaire twice within 7 days. Test-retest reliability of individual items and scales within the CAPANS-PA questionnaire was determined using Kappa statistics for categorical variables and intraclass correlation coefficients (ICC) for continuous variables. RESULTS: The CAPANS-PA questionnaire demonstrated acceptable test-retest reliability for frequency and duration of time spent in weekly Moderate to Vigorous Physical Activity (MVPA) (ICC ≥ 0.70) for all participants. Test-retest reliability for time spent in weekly sedentary activities was acceptable for females (ICC = 0.82) and males (ICC = 0.72). CONCLUSIONS: The results suggest the CAPANS-PA questionnaire provides reliable estimates for type, frequency and duration of MVPA participation among Chinese-Australian youth. Further investigation into the reliability of the sedentary items within the CAPANS-PA is required before these items can be used with confidence. This study is novel in that the reliability of instruments among CALD groups nationally and internationally remains sparse and this study contributes to the wider body of available psychometrically tested instruments. In addition, this study is the first to our knowledge to successfully engage and investigate the basic health enhancing behaviours of Chinese-Australian adolescents.