Criterion and concurrent validity of the activPAL (TM) professional physical activity monitor in adolescent females

peer-reviewedBackground: The activPAL has been identified as an accurate and reliable measure of sedentary behaviour. However, only limited information is available on the accuracy of the activPAL activity count function as a measure of physical activity, while no unit calibration of the activPAL has been completed to date. This study aimed to investigate the criterion validity of the activPAL, examine the concurrent validity of the activPAL, and perform and validate a value calibration of the activPAL in an adolescent female population. The performance of the activPAL in estimating posture was also compared with sedentary thresholds used with the ActiGraph accelerometer.Methodologies: Thirty adolescent females (15 developmental; 15 cross-validation) aged 15-18 years performed 5 activities while wearing the activPAL, ActiGraph GT3X, and the Cosmed K4B2. A random coefficient statistics model examined the relationship between metabolic equivalent (MET) values and activPAL counts. Receiver operating characteristic analysis was used to determine activity thresholds and for cross-validation. The random coefficient statistics model showed a concordance correlation coefficient of 0.93 (standard error of the estimate = 1.13). An optimal moderate threshold of 2997 was determined using mixed regression, while an optimal vigorous threshold of 8229 was determined using receiver operating statistics. The activPAL count function demonstrated very high concurrent validity (r = 0.96, pPUBLISHEDpeer-reviewe

Study design and protocol for a mixed methods evaluation of an intervention to reduce and break up sitting time in primary school classrooms in the UK: the CLASS PAL (Physically Active Learning) Programme

Introduction: Children engage in a high volume of sitting in school, particularly in the classroom. A number of strategies, such as physically active lessons (termed movement integration (MI)), have been developed to integrate physical activity into this learning environment; however, no single approach is likely to meet the needs of all pupils and teachers. This protocol outlines an implementation study of a primary school-based MI intervention: CLASS PAL (Physically Active Learning) programme. This study aims to (A) determine the degree of implementation of CLASS PAL, (B) identify processes by which teachers and schools implement CLASS PAL and (C) investigate individual (pupil and teacher) level and school-level characteristics associated with implementation of CLASS PAL. Methods and analysis: The intervention will provide teachers with a professional development workshop and a bespoke teaching resources website. The study will use a single group before-and-after design, strengthened by multiple interim measurements. Six state-funded primary schools will be recruited within Leicestershire, UK. Evaluation data will be collected prior to implementation and at four discrete time points during implementation: At measurement 0 (October 2016), school, teacher and pupil characteristics will be collected. At measurements 0 and 3 (June-July 2017), accelerometry, cognitive functioning, self-reported sitting and classroom engagement data will be collected. At measurements 1(December 2016-March 2017) and 3, teacher interviews (also at measurement 4; September-October 2017) and pupil focus groups will be conducted, and at measurements 1 and 2 (April-May 2017), classroom observations. Implementation will be captured through website analytics and ongoing teacher completed logs. Ethics and dissemination: Ethical approval was obtained through the Loughborough University Human Participants Ethics Sub-Committee (Reference number: R16-P115). Findings will be disseminated via practitioner and/or research journals and to relevant regional and national stakeholders through print and online media and dissemination event(s)

Moderate-to-vigorous intensity physical activity during school hours in a representative sample of 10–11-year-olds in Scotland

Objectives: Growing concern about children and adolescent physical inactivity has made the promotion of physical activity a public health priority. International recommendations suggest children should accumulate at least 30 min of moderate-to-vigorous physical activity (MVPA) during school hours. This study assessed levels of objectively-measured MVPA in a large nationally representative sample of Scottish children aged 10–11. Risk factors for not meeting the school-hours MVPA recommendation were examined. Design: Cross-sectional. Methods: Mean time spent in MVPA during school hours across five weekdays was measured using Actigraph accelerometry (May 2015–May 2016). Binary logistic regression, presented as odds ratio (O.R.) and confidence intervals (C.I.), explored associations between meeting/not meeting the recommendation by sex, socioeconomic status (SES), season, and urban/rural residence in 2022. Results: Valid data were obtained from 773 children (53.9% girls, 46.1% boys) from 471 schools. Mean daily school-hours MVPA was 29 (SD 11) minutes; 42.7% of children reached the recommendation. The odds of girls (O.R. 0.43; C.I. 0.32, 0.57) meeting the recommendation was significantly lower (p < 0.001) compared to boys. Children living in rural areas had higher odds (O.R. 1.49; C.I. 1.04, 2.15) of meeting the recommendation compared with those in urban areas (p = 0.032). No significant differences in meeting the recommendation by SES (p = 0.700). The overall trend for season was significant (p < 0.001), with lower odds of meeting the recommendation in winter compared to summer. Conclusions: Most Scottish children aged 10–11 did not meet the 30 minute MVPA recommendation. Interventions to increase MVPA during school hours are essential to promote public health

Maturational timing, physical self-perceptions and physical activity in UK adolescent females: Investigation of a mediated effects model

Background: Advanced (early) biological maturation may be a risk factor for inactivity among adolescent girls. The aim of the present paper was to test the mediational effects of body attractiveness and physical self-worth on the relationship between biological maturity and accelerometer assessed moderate-to-vigorous physical activity (MVPA) in a large multi-ethnic sample of girls from the Midlands area in the UK (11-14 years). Methods: Biological maturity (predicting age at peak height velocity (APHV)); self-perceptions of body attractiveness, physical self-worth, and minutes spent in MVPA were assessed in 1062 females aged 11 to 14 years. Results: Structural equation modeling using maximum likelihood estimation and boot- strapping procedures supported the hypothesized model. Later maturation predicted higher perceptions of body attractiveness (β=.25, p<.001) which, in turn, predicted higher perceptions of physical self-worth (β=.91, p<.001) and, significantly higher MVPA (β=.22, p<.001). Examination of the bootstrap-generated bias-corrected confidence intervals suggested that perceptions of body attractiveness and physical self-worth partially mediated a positive association between predicted APHV and MVPA (β=.05, p Conclusions: Greater biological maturity (i.e. early maturity) in adolescent girls is associated with less involvement in MVPA and appears to be partly explained by lower perceptions of body attractiveness and physical self-worth. Physical activity interventions should consider girls perceptions of their pubertal related physiological changes during adolescence, particularly among early maturing girls. </p

Correlates of total sedentary time and screen time in 9-11 year-old children around the world : the international study of childhood obesity, lifestyle and the environment

Purpose: Previously, studies examining correlates of sedentary behavior have been limited by small sample size, restricted geographic area, and little socio-cultural variability. Further, few studies have examined correlates of total sedentary time (SED) and screen time (ST) in the same population. This study aimed to investigate correlates of SED and ST in children around the world. Methods: The sample included 5,844 children (45.6% boys, mean age = 10.4 years) from study sites in Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, the United Kingdom, and the United States. Child- and parent-reported behavioral, household, and neighborhood characteristics and directly measured anthropometric and accelerometer data were obtained. Twenty-one potential correlates of SED and ST were examined using multilevel models, adjusting for sex, age, and highest parental education, with school and study site as random effects. Variables that were moderately associated with SED and/or ST in univariate analyses (p<0.10) were included in the final models. Variables that remained significant in the final models (p<0.05) were considered correlates of SED and/or ST. Results: Children averaged 8.6 hours of daily SED, and 54.2% of children failed to meet ST guidelines. In all study sites, boys reported higher ST, were less likely to meet ST guidelines, and had higher BMI z-scores than girls. In 9 of 12 sites, girls engaged in significantly more SED than boys. Common correlates of higher SED and ST included poor weight status, not meeting physical activity guidelines, and having a TV or a computer in the bedroom. Conclusions: In this global sample many common correlates of SED and ST were identified, some of which are easily modifiable (e.g., removing TV from the bedroom), and others that may require more intense behavioral interventions (e.g., increasing physical activity). Future work should incorporate these findings into the development of culturally meaningful public health messages

The descriptive epidemiology of sitting among US adults, NHANES 2009/2010

Objectives: Using NHANES 2009/2010, to describe the amount of time a representative sample of the U.S. population spends sitting by age, sex, ethnicity, education, and body mass index. Design: Cross-sectional analysis. Methods: Participants (n= 5911, ≥20 years) self-reported demographic variables and the amount of time they spend sitting on a typical day. Body mass index was calculated from measured height and weight. Results: Mean self-reported sitting time was 285. min/day for males and 281. min/day for females. Mexican-Americans reported sitting less than both non-Hispanic Whites and non-Hispanic Blacks (all p <0.0001). Non-Hispanic White males reported sitting more than non-Hispanic Black males, while Non-Hispanic White females reported sitting more than Other Hispanic females (both p <0.0001). No significant differences were found between sexes in any age group. There was a trend for increased sitting time with increasing age for females (p for trend = 0.0045), for all Mexican-American and Hispanic participants and non-Hispanic Black males (all p ≤ 0.006) and with increasing education (p for trend <0.0001). At the College Graduate level, females reported sitting less than males (p < 0.0001). Obese females reported sitting more than normal weight and overweight females (p = 0.0008). There were no significant differences in sitting time by body mass index for males. Conclusions: Self-reported sitting time differed by ethnicity, age group, education and body mass index but there was no overall difference by sex. These results represent the most up to date prevalence of self-reported sitting for the US adult population. Certain groups should be targeted to reduce sitting time, for example those with higher educational attainment and obese females

Television, adiposity, and cardiometabolic risk in children and adolescents

Background: It is largely unknown how TV use relates to depot-specific adiposity or cardiometabolic risk in children. Purpose: To examine relationships between having a TV in the bedroom and TV viewing time with total fat mass, abdominal subcutaneous and visceral adiposity, and cardiometabolic risk in children and adolescents. Methods: A cross-sectional study of 369 children and adolescents aged 5-18 years was conducted (2010-2011; analysis 2011-2012). Waist circumference; resting blood pressure; fasting triglycerides, high-density lipoprotein cholesterol [HDL-C] and glucose; fat mass by dual-energy x-ray absorptiometry; and abdominal subcutaneous and visceral adiposity by MRI were assessed. Cardiometabolic risk was defined as three or more risk factors including adverse levels of waist circumference, blood pressure, triglycerides, HDL-C, and glucose. Logistic regression analysis was used to compute ORs of high fat mass; subcutaneous and visceral adipose tissue mass (top age-adjusted quartile); and cardiometabolic risk, based on self-reported TV present in the bedroom and TV viewing time, controlling for age, gender, ethnicity, moderate-to-vigorous physical activity level, and unhealthy diet. Results: In multivariable models, presence of a TV in the bedroom and TV viewing time were associated with (p<0.05) higher odds of high waist circumference (OR=1.9–2.1); fat mass (OR=2.0–2.5); and subcutaneous adiposity (OR=2.1–2.9), whereas viewing TV ≥5 hours/day was associated with high visceral adiposity (OR=2.0). Having a TV in the bedroom was associated with elevated cardiometabolic risk (OR=2.9) and high triglycerides (OR=2.0). Conclusions Having a bedroom TV and TV viewing time were related to high waist circumference, fat mass, and abdominal subcutaneous adiposity. TV viewing time was related to visceral adiposity, and bedroom TV was related to cardiometabolic risk in children, controlling for moderate-to-vigorous physical activity and an unhealthy diet

BMI percentiles for the identification of abdominal obesity and metabolic risk in children and adolescents : evidence in support of the CDC 95th percentile

Objectives:Body mass index (BMI) percentiles have been routinely and historically used to identify elevated adiposity. The aim of this study was to investigate the optimal Centers for Disease Control and Prevention (CDC) BMI percentile that predicts elevated visceral adipose tissue (VAT), fat mass and cardiometabolic risk in a biracial sample of children and adolescents. Participants and Methods: This cross-sectional analysis included 369 white and African-American children (5-18 years). BMI was calculated using height and weight and converted to BMI percentiles based on CDC growth charts. Receiver operating characteristic curve analysis identified the optimal (balance of sensitivity and specificity) BMI percentile to predict the upper quartile of age-adjusted VAT (measured by magnetic resonance imaging), age-adjusted fat mass (measured by dual-energy X-ray absorptiometry) and elevated cardiometabolic risk (≥2 of high glucose, triglycerides and blood pressure, and low high-density lipoprotein cholesterol) for each race-by-sex group. Results: The optimal CDC BMI percentile to predict those in the top quartile of age-adjusted VAT, age-adjusted fat mass and elevated cardiometabolic risk were the 96th, the 96th and the 94th percentiles, respectively, for the sample as a whole. Sensitivity and specificity was satisfactory (>0.70) for VAT and fat mass. Compared to VAT and fat mass, there was a lower overall accuracy of the optimal percentile in identifying those with elevated cardiometabolic risk. Conclusions: The present findings support the utility of the 95th CDC BMI percentile as a useful threshold for the prediction of elevated levels of VAT, fat mass and cardiometabolic risk in children and adolescents

Results from Ireland\u27s 2014 report card on physical activity in children and youth

Background: Physical activity (PA) levels are a key performance indicator for policy documents in Ireland. The first Ireland Report Card on Physical Activity in Children and Youth aims to set a robust baseline for future surveillance of indicators related to PA in children and youth. Methods: Data collected between 2003-2010 on more than 35,000 7- to 18-year-old children and youth were used and graded using a standardized grading system for 10 indicators. Results: Grades assigned for the indicators were as follows: overall physical activity levels, D-; sedentary behavior (TV viewing), C-; organized sport participation, C-: physical education, D-; active play, inconclusive (INC); active transportation, D; school, C-, community and the built environment, B; family, INC; and government, INC. Conclusions: PA recommendations exist in Ireland but this Report Card has shown that participation is still low. A number of promising policies, programs and services are in place but these require thorough evaluation and adequate resourcing. Agreement and implementation of a common framework for the systematic surveillance of indictors related to PA of children and youth is necessary to monitor change over time and ensure the impact of promising work is captured