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Background: Research on physically active learning (PAL) has mainly been investigated experimentally, where interventions have been introduced to study effects on, for example, physical activity (PA) levels. This might undermine real-world contexts and realistic PA levels when teachers have sustained PAL in their regular teaching practice for several years. The purpose of this study was to observe and describe the organization and content of a variety of teaching where PAL was enacted by experienced teachers and to describe the corresponding PA levels and PA intensity in real-world practices., Methods: Fifty-eight pupils and four teachers from one primary school and one secondary school were enrolled across the first, sixth, and eighth grades. The pupils' physical activity (PA) levels were assessed during 37 enacted physically active learning (PAL) segments within longer teaching lessons using waist-worn triaxial accelerometers. Evenson cut-off points were employed to define PA intensities. All enacted PAL were passively observed by the same observer regarding primary bodily movement, duration, subject, location, collaborative or individual work, and task orientation., Results: On average, PAL consisted of 57.8% ± 15.7% sedentary time, 22.9% ± 7.5% light intensity PA, and 19.3% ± 10.8% moderate-to-vigorous intensity PA, displaying a large variety in different PAL segments. More intensive and higher volumes of PA were evident when PAL was facilitated outdoors, in gyms, or in large stairways, while lower PA volumes and intensity were assessed when PAL was enacted inside the classroom. The primary movement in PAL was mainly running and/or walking (78.3%), while the PAL activity was mainly organized as group work (83.7%) in non-competitive tasks (97.3%)., Conclusions: This study provides novel insights by being the first to investigate the organization and content of PAL enacted by experienced teachers in their teaching and the corresponding PA levels in their real-world practices. The results displayed a large diversity in PA levels and intensities and may serve as a starting point to further investigate the coherency of PA levels and PAL content in schools with sustained PAL teaching., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2025 Johansen, Mandelid, Reinboth, Resaland and Bratland-Sanda.)

Background: Teachers are recognized as 'key agents' for the delivery of physical activity programs and policies in schools. The aim of our study was to develop and evaluate a tool to assess teachers' capability, opportunity, and motivation to deliver school-based physical activity interventions., Methods: The development and evaluation of the Capability, Opportunity, and Motivation to deliver Physical Activity in School Scale (COM-PASS) involved three phases. In Phase 1, we invited academic experts to participate in a Delphi study to rate, provide recommendations, and achieve consensus on questionnaire items that were based on the Capability, Opportunity, and Motivation Behavior (COM-B) model. Each item was ranked on the degree to which it matched the content of the COM-B model, using a 5-point scale ranging from '1 = Poor match' to '5 = Excellent match'. In Phase 2, we interviewed primary and secondary school teachers using a 'think-aloud' approach to assess their understanding of the items. In Phase 3, teachers (n = 196) completed the COM-PASS to assess structural validity using confirmatory factor analysis (CFA)., Results: Thirty-eight academic experts from 14 countries completed three rounds of the Delphi study. In the first round, items had an average rating score of 4.04, in the second round 4.51, and in the third (final) round 4.78. The final tool included 14 items, which related to the six constructs of the COM-B model: physical capability, psychological capability, physical opportunity, social opportunity, reflective motivation, and automatic motivation. In Phase 2, ten teachers shared their interpretation of COM-PASS via a 20-min interview, which resulted in minor changes. In Phase 3, CFA of the 3-factor model (i.e., capability, opportunity, and motivation) revealed an adequate fit to the data (χ 2  = 122.6, p < .001, CFI = .945, TLI = .924, RMSEA = .066). The internal consistencies of the three subscale scores were acceptable (i.e., capability: α = .75, opportunity: α = .75, motivation: α = .81)., Conclusion: COM-PASS is a valid and reliable tool for assessing teachers' capability, opportunity, and motivation to deliver physical activity interventions in schools. Further studies examining additional psychometric properties of the COM-PASS are warranted., (© 2024. The Author(s).)

Background: Previous research has suggested that school-based physical activity (PA) interventions may have a positive impact on academic performance. However, existing literature on school-based interventions encompasses various forms of PA, spanning from vigorous intensity PA outside the academic classes to light intensity PA and movement integrated into academic learning tasks, and results on academic performance are inconclusive. ACTIVE SCHOOL will implement two different PA interventions for one school year and assess the effects on the pupils' academic performance, with math performance as the primary outcome., Methods/design: The ACTIVE SCHOOL project consists of two phases: 1) Development phase and 2) Randomized Controlled Trial (RCT). In phase one, two interventions were developed in collaboration with school staff. The two interventions were tested in an 8-weeks feasibility study. In phase two, a RCT-study with three arms will be conducted in 9-10-year-old children for one school year. The RCT-study will be carried out in two intervention rounds during the school years 2023/2024 and 2024/2025. Schools will be randomized to one of two interventions or control;1) Run, Jump & Fun intervention (4 × 30 min/week of moderate-to-vigorous physical activity; 2) Move & Learn intervention (4 × 30 min/week focusing on embodied learning in math and Danish lessons); or 3) a control condition, consisting of normal teaching practices. Outcome measures include academic performance, PA level, cognitive functions, cardiorespiratory fitness, anthropometry, well-being and school motivation (collected before, during and after the intervention period). A process evaluation will be conducted to assess implementation., Discussion: The ACTIVE SCHOOL study will expand knowledge regarding the impact of PA on academic performance. The study will have the potential to significantly contribute to future research, as well as the scientific and educational debate on the best way to implement PA to support education and learning., Trial Registration: The study was registered on the 25th of October 2022 in ClinicalTrials.gov, NCT05602948., (© 2024. The Author(s).)

Background: Active travel and school settings are considered ideal for promoting physical activity. However, previous research suggests limited effect of school-based interventions on overall physical activity levels among adolescents. The relationship between physical activity in different domains remains inconclusive. In this study, we examined the effects of adding two weekly hours of school-based physical activity on active travel rates., Method: We analyzed data from 1370 pupils in the 9th-grade participating in the cluster RCT; the School In Motion (ScIM) project. Intervention schools (n = 19) implemented 120 min of class-scheduled physical activity and physical education, in addition to the normal 2 hours of weekly physical education in the control schools (n = 9), for 9 months. Active travel was defined as pupils who reported walking or cycling to school, while motorized travel was defined as pupils who commuted by bus or car, during the spring/summer half of the year (April-September), or autumn/winter (October-February). The participants were categorized based on their travel mode from pretest to posttest as; maintained active or motorized travel ("No change"), changing to active travel (motorized-active), or changing to motorized travel (active-motorized). Multilevel logistic regression was used to analyze the intervention effect on travel mode., Results: During the intervention period, most participants maintained their travel habits. In total, 91% of pupils maintained their travel mode to school. Only 6% of pupils switched to motorized travel and 3% switched to active travel, with small variations according to season and trip direction. The intervention did not seem to influence the likelihood of changing travel mode. The odds ratios for changing travel habits in spring/summer season were from active to motorized travel 1.19 [95%CI: 0.53-2.15] and changing from motorized to active travel 1.18 [0.30-2.62], compared to the "No change" group. These findings were consistent to and from school, and for the autumn/winter season., Conclusion: The extra school-based physical activity does not seem to affect rates of active travel among adolescents in the ScIM project., Trial Registration: Clinicaltrials.gov ID nr: NCT03817047. Registered 01/25/2019' retrospectively registered'., (© 2023. The Author(s).)

Background: Physically active learning (PAL) has emerged as a promising way of eliciting health and education-based outcomes for pupils. Concurrently, research suggests large variability in how PAL is perceived, operationalized, and prioritized in practice across Europe. Therefore, this study aimed to co-develop a framework for action to support the adoption and implementation of PAL., Methods: Adopting a design thinking approach, 40 international stakeholders representing 13 countries engaged in an idea generation workshop during a two-day PAL international conference. Participants included professionals from research (n = 20), practice (n = 4) and policy (n = 1) or a combination (n = 15). Their experience with PAL ranged from none to 19 years (with an average of 3.9 years). Participants were allocated into one of six heterogeneous and multidisciplinary groups and led through interactive tasks to identify: the landscape for PAL across Europe, barriers to the adoption and implementation of PAL, and key objectives for research, policy and practice to improve the adoption and implementation of PAL. All discussions were audio recorded and prioritized objectives were transcribed verbatim and analysed using inductive qualitative content analysis., Results: Five interlinked and mutually reinforcing themes were identified: (1) Integration of the health and education paradigms (2) Coherent national policy and decision making (3) Building confident and competent teachers (4) Adopting a whole school approach for PAL (5) Strengthening the evidence base for PAL., Conclusions: The priority action framework identifies five key areas for action to facilitate PAL adoption and implementation across Europe. Central to the success of border uptake of PAL is the integration of the health and education paradigms. To achieve this aim, reframing PAL as movement-centered pedagogy would provide a more holistic and inclusive perspective., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: While there have been several school-based physical activity (PA) interventions targeting improvement in cardiovascular disease (CVD) risk factors, few have assessed long-term effects. The aim of this paper was therefore to determine intervention effects on CVD risk factors 5 years after cessation., Methods: Two schools were assigned to intervention (n = 125) or control (n = 134). The intervention school offered 210 min/week more PA than the control school over two consecutive years (fourth and fifth grades). Follow-up assessment was conducted 5-year post-intervention (10th grade) where 180-210 (73%-85%) children provided valid data. Outcomes were CVD risk factors: triglyceride, total-to-high-density-lipoprotein-cholesterol ratio (TC:HDL ratio), insulin resistance, blood pressure (BP), waist circumference, and cardiorespiratory fitness (VO 2peak ). Variables were analyzed individually and as a composite score through linear mixed models, including random intercepts for children., Results: Analyses revealed significant sustained 5-year intervention effects for HDL (effect sizes [ES] = 0.22), diastolic BP (ES = 0.48), VO 2peak (ES = 0.29), and composite risk score (ES = 0.38). These effects were similar to the immediate results following the intervention. In contrast, while TC:HDL ratio initially decreased post-intervention (ES = 0.27), this decrease was not maintained at 5-year follow-up (ES = 0.09), whereas WC was initially unchanged post-intervention (ES = 0.02), but decreased at 5-year follow-up (ES = 0.44)., Conclusion: The significant effects of a 2-year school-based PA intervention remained for CVD risk factors 5 years after cessation of the intervention. As cardiometabolic health can be maintained long-term after school-based PA, this paper demonstrates the sustainability and potential of schools in the primary prevention of future CVD risk in children., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aims: This cross-sectional study investigated the association between health-related quality of life (HRQoL), cardiorespiratory fitness (CRF) and muscular fitness in 14-year-old adolescents., Methods: Norwegian adolescents (N = 1985) carried out a 10-min running test to assess cardiorespiratory fitness and three different muscular fitness tests (handgrip, sit-ups, and standing broad jump) and answered the KIDSCREEN-27 questionnaire to provide HRQoL data. Linear-mixed effect models were applied to detect relationships among the variables., Results: Running-test results were positively associated with higher scores in the following KIDSCREEN domains: physical well-being, psychological well-being, autonomy and parent relationships, and school environment (β = 0.01-0.04; p < .01 for all). Performance in sit-ups test was positively associated with higher scores in three out of five KIDSCREEN domains: physical well-being (β = 0.31; p < .001), social support and peers (β = 0.16; p = .023), and school environment scores (β = 0.19; p = .006). An inverse association was found between the handgrip test results and the score on psychological well-being domain (β = - 0.10; p = .013)., Conclusions: The associations between HRQoL and physical fitness were trivial (abdominal strength and handgrip strength) to small (CRF) but confirmed that earlier findings from children also are applied to adolescents. Explosive strength in the lower body showed no association with HRQoL. Further research should investigate the direction of causality., Trial Registration: Clinicaltrials.gov ID nr: NCT03817047. Registered 01/25/2019 'retrospectively registered'., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Introduction/purpose: Recess represents a prime opportunity for physical activity during the school day. However, evidence is mixed with regard to factors associated with activity during recess., Methods: Data were collected as a part of the Texas Initiative for Children's Activity and Nutrition (I-CAN!) program from 14 elementary schools and 1,049 4 th -grade students. Percent of time in moderate-to-vigorous physical activity (MVPA) and sedentary behavior during recess was measured using GT3X+ accelerometers. Students' demographics, aerobic fitness, and body mass index (BMI) were collected from school records and FITNESSGRAM® data. Aspects of the playground environment supporting activity (e.g. soccer goals) or sedentary behavior (e.g. benches) were calculated following the procedures of the System for Observing Play and Leisure Activity in Youth (SOPLAY), with recess spatial area calculated via the polygon measurement tool in Google™ Earth Pro software. Recess time was collected from school data. Weather during recess was determined using time-stamped archived weather data from Weather Underground. Two-level, linear mixed model regression examined associations between individual- and school-level characteristics and percent time in MVPA., Results: At the student-level, boys were more active than girls (effect size (ES)=0.50) and percent time in MVPA was directly associated with aerobic fitness (ES=0.35). At the school-level, recess infrastructure was associated with percent time in MVPA (ES=1.45), except for factors related to sedentary behavior, which were indirectly associated with percent time in MVPA (ES=-1.98). Patterns for sedentary behavior mirrored these effects., Conclusions: This is one of the few studies to test the associations of fitness and sedentary upgrades to play areas with MVPA and sedentary behavior. The results suggest that recess is most likely to support MVPA in boys and those who are already most fit (i.e., those who would not be the target of intervention). This is not surprising because the focus of recess is on free choice of play, and thus recess might be supported more for social and emotional benefits than the impact on physical activity., Competing Interests: Conflict of Interest (COI) The authors report no conflicts of interest.

Background: Our understanding of the mechanisms through which physical activity might benefit lipoprotein metabolism is inadequate. Here we characterise the continuous associations between physical activity of different intensities, sedentary time, and a comprehensive lipoprotein particle profile., Methods: Our cohort included 762 fifth grade (mean [SD] age = 10.0 [0.3] y) Norwegian schoolchildren (49.6% girls) measured on two separate occasions across one school year. We used targeted proton nuclear magnetic resonance ( 1 H NMR) spectroscopy to produce 57 lipoprotein measures from fasted blood serum samples. The children wore accelerometers for seven consecutive days to record time spent in light-, moderate-, and vigorous-intensity physical activity, and sedentary time. We used separate multivariable linear regression models to analyse associations between the device-measured activity variables-modelled both prospectively (baseline value) and as change scores (follow-up minus baseline value)-and each lipoprotein measure at follow-up., Results: Higher baseline levels of moderate-intensity and vigorous-intensity physical activity were associated with a favourable lipoprotein particle profile at follow-up. The strongest associations were with the larger subclasses of triglyceride-rich lipoproteins. Sedentary time was associated with an unfavourable lipoprotein particle profile, the pattern of associations being the inverse of those in the moderate-intensity and vigorous-intensity physical activity analyses. The associations with light-intensity physical activity were more modest; those of the change models were weak., Conclusion: We provide evidence of a prospective association between time spent active or sedentary and lipoprotein metabolism in schoolchildren. Change in activity levels across the school year is of limited influence in our young, healthy cohort., Trial Registration: ClinicalTrials.gov , # NCT02132494 . Registered 7th April 2014., (© 2022. The Author(s).)

Little information exists on the mechanism of how physical activity interventions effects academic performance. We examined whether the effects of a school-based physical activity intervention on academic performance were mediated by aerobic fitness. The School in Motion study was a nine-month cluster randomized controlled trial between September 2017 and June 2018. Students from 30 Norwegian lower secondary schools ( N  = 2,084, mean age [ SD ] = 14 [0.3] years) were randomly assigned into three groups: the Physically Active Learning (PAL) intervention ( n  = 10), the Don't Worry-Be Happy (DWBH) intervention ( n  = 10), or control ( n  = 10). Aerobic fitness was assessed by the Andersen test and academic performance by national tests in reading and numeracy. Mediation was assessed according to the causal steps approach using linear mixed models. In the PAL intervention, aerobic fitness partially mediated the intervention effect on numeracy by 28% from a total effect of 1.73 points (95% CI: 1.13 to 2.33) to a natural direct effect of 1.24 points (95% CI: 0.58 to 1.91), and fully mediated the intervention effect on reading, with the total effect of 0.89 points (95% CI: 0.15 to 1.62) reduced to the natural direct effect of 0.40 points (95% CI: -0.48 to 1.28). Aerobic fitness did not mediate the effects on academic performance in the DWBH intervention. As aerobic fitness mediated the intervention effect on academic performance in one intervention, physical activity of an intensity that increases aerobic fitness is one strategy to improve academic performance among adolescents., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)

Background: Physically active learning (PAL) - integration of movement within delivery of academic content - is a core component of many whole-of-school physical activity approaches. Yet, PAL intervention methods and strategies vary and frequently are not sustained beyond formal programmes. To improve PAL training, a more comprehensive understanding of the behavioural and psychological processes that influence teachers' adoption and implementation of PAL is required. To address this, we conducted a meta-synthesis to synthesise key stakeholders' knowledge of facilitators and barriers to teachers' implementing PAL in schools to improve teacher-focussed PAL interventions in primary (elementary) schools., Methodology: We conducted a meta-synthesis using a five-stage thematic synthesis approach to; develop a research purpose and aim, identify relevant articles, appraise studies for quality, develop descriptive themes and interpret and synthesise the literature. In the final stage, 14 domains from the Theoretical Domain Framework (TDF) were then aligned to the final analytical themes and subthemes., Results: We identified seven themes and 31 sub-themes from 25 eligible papers. Four themes summarised teacher-level factors: PAL benefits, teachers' beliefs about own capabilities, PAL teacher training, PAL delivery. One theme encompassed teacher and school-level factors: resources. Two themes reflected school and external factors that influence teachers' PAL behaviour: whole-school approach, external factors. Ten (of 14) TDF domains aligned with main themes and sub-themes: Knowledge, Skills, Social/Professional Role and Identity, Beliefs about Capabilities, Beliefs about Consequences, Reinforcement, Goals, Environmental Context and Resources, Social influences and Emotion., Conclusions: Our synthesis illustrates the inherent complexity required to change and sustain teachers' PAL behaviours. Initially, teachers must receive the training, resources and support to develop the capability to implement and adapt PAL. The PAL training programme should progress as teachers' build their experience and capability; content should be 'refreshed' and become more challenging over time. Subsequently, it is imperative to engage all levels of the school community for PAL to be fully integrated into a broader school system. Adequate resources, strong leadership and governance, an engaged activated community and political will are necessary to achieve this, and may not currently exist in most schools., (© 2021. The Author(s).)

Aerobic fitness (AF) and lipoprotein subclasses associate to each other and to cardiovascular health. Adiposity and physical activity (PA) influence the association pattern of AF to lipoproteins almost inversely making it difficult to assess their independent and joint influence on the association pattern. This study, including 841 children (50% boys) 10.2 ± 0.3 years old with BMI 18.0 ± 3.0 kg/m2 from rural Western Norway, aimed at examining the association pattern of AF to the lipoprotein subclasses and to estimate the independent and joint influence of PA and adiposity on this pattern. We used multivariate analysis to determine the association pattern of a profile of 26 lipoprotein features to AF with and without adjustment for three measures of adiposity and a high-resolution PA descriptor of 23 intensity intervals derived from accelerometry. For data not adjusted for adiposity or PA, we observed a cardioprotective lipoprotein pattern associating to AF. This pattern withstood adjustment for PA, but the strength of association to AF was reduced by 58%, while adjustment for adiposity weakened the association of AF to the lipoproteins by 85% and with strongest changes in the associations to a cardioprotective high-density lipoprotein subclass pattern. When adjusted for both adiposity and PA, the cardioprotective lipoprotein pattern still associated to AF, but the strength of association was reduced by 90%. Our results imply that the (negative) influence of adiposity on the cardioprotective association pattern of lipoproteins to AF is considerably stronger than the (positive) contribution of PA to this pattern. However, our analysis shows that PA contributes also indirectly through a strong inverse association to adiposity. The trial was registered 7 May, 2014 in clinicaltrials.gov with trial reg. no.: NCT02132494 and the URL is https://clinicaltrials.gov/ct2/results?term=NCT02132494&cntry=NO., Competing Interests: The authors have declared that no competing interests exist.

There is an adverse cross-sectional association between sedentary time, physical activity (PA) and adiposity, but weak and inconsistent estimates raise question to the direction of associations. The present study aims to examine whether the prospective association between sedentary time, different PA intensities and indicators of adiposity is bi-directional. The Active Smarter Kids Study obtained data from 869 ten-year-old children with valid measurements for sedentary time, PA, and adiposity at baseline and follow-up. Time spent sedentary and PA was measured by accelerometry, adiposity was assessed by three different measures: body mass index (BMI), waist circumference (WC) and sum of four skinfolds (S4SF). Neither overall PA nor time spent sedentary predicted lower BMI or WC at follow-up, but the time spent in moderate-and-vigorous PA (MVPA) and vigorous PA (VPA) predicted lower S4SF at follow-up among boys (MVPA β  - 0.066 [95% CI -0.105, -0.027]  p = 0.001). Baseline BMI and WC predicted less overall PA, MVPA and VPA in boys. All adiposity measures predicted more time spent sedentary at follow-up in boys. The results suggest that overall PA and sedentary time do not predict future adiposity. Baseline adiposity may rather predict more sedentary time and less higher intensity activity.

Lipoprotein subclasses possess crucial cardiometabolic information. Due to strong multicollinearity among variables, little is known about the strength of influence of physical activity (PA) and adiposity upon this cardiometabolic pattern. Using a novel approach to adjust for covariates, we aimed at determining the "net" patterns and strength for PA and adiposity to the lipoprotein profile. Principal component and multivariate pattern analysis were used for the analysis of 841 prepubertal children characterized by 26 lipoprotein features determined by proton nuclear magnetic resonance spectroscopy, a high-resolution PA descriptor derived from accelerometry, and three adiposity measures: body mass index, waist circumference to height, and skinfold thickness. Our approach focuses on revealing and validating the underlying predictive association patterns in the metabolic, anthropologic, and PA data to acknowledge the inherent multicollinear nature of such data. PA associates to a favorable cardiometabolic pattern of increased high-density lipoproteins (HDL), very large and large HDL particles, and large size of HDL particles, and decreasedtriglyceride, chylomicrons, very low-density lipoproteins (VLDL), and their subclasses, and to low size of VLDL particles. Although weakened in strength, this pattern resists adjustment for adiposity. Adiposity is inversely associated to this pattern and exhibits unfavorable associations to low-density lipoprotein (LDL) features, including atherogenic small and very small LDL particles. The observed associations are still strong after adjustment for PA. Thus, lipoproteins explain 26.0% in adiposity after adjustment for PA compared to 2.3% in PA after adjustment for adiposity.

Objectives: The aim was to determine the independent associations of muscular fitness (MF), cardiorespiratory fitness (CRF) and waist circumference (WC) with blood pressure (BP) levels over 2 years in children and adolescents., Methods: 1089 children (517 females) and 787 adolescents (378 females) with complete data on fitness, WC and BP (systolic [SBP] and diastolic [DBP]) were included. Upper MF was assessed through the handgrip strength test, and lower MF using the standing long jump test. The 20-m shuttle run test was used to assess CRF. WC was obtained following standardized methods. Different regression models were fitted by introducing fitness and WC at baseline and their changes as exposures and BP at follow-up and their changes as outcomes., Results: WC at baseline was positively and independently associated with each BP variable at follow-up in children and adolescents (β=0.094-0.260; p≤0.05), and CRF was negatively associated with DBP in adolescents (β=-0.096; p=0.034). WC changes were associated with BP variables 2 years later in children (β=0.121-0.142; p<0.01). In adolescents, changes in upper MF (β=-0.116; p=0.001) and WC (β=0.080-0.098; p<0.05) were associated with SBP at follow-up. WC changes were independently associated with changes in each BP variable in children (β=0.111-0.145; all p<0.05) and SBP changes in adolescents (β=0.103 to 0.117; all p<0.01)., Conclusions: WC, but neither MF nor CRF, is independently associated with BP and its changes over 2 years. The attainment or maintenance of optimal fatness levels in the pediatric population should be highly encouraged for the prevention of future hypertension., (Copyright © 2021 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Background: School-based physical activity interventions evaluating the effect on academic performance usually includes children. We aimed to investigate the effect of a nine-month, school-based physical activity intervention titled School in Motion (ScIM) on academic performance in adolescents., Methods: Thirty secondary schools in Norway were cluster-randomized into three groups: the Physically active learning (PAL) group (n = 10), the Don't worry - Be Happy (DWBH) group (n = 10) or control (n = 10). Target dose in both intervention groups was 120 min/week of additional PA during school hours. Parental consent was obtained from 2084 adolescent students (76%). Standardized national tests in reading and numeracy was conducted at baseline and at the end of the intervention. We used linear mixed model to test intervention effects. We found significant intervention effects in numeracy and reading among students in both interventions when compared with controls., Results: The mean difference in change in numeracy was 1.7 (95% CI: 0.9 to 2.5; Cohen's d = 0.12) and 2.0 (95% CI: 1.4 to 2.7; Cohen's d = 0.23) points in favour of students in the PAL and DWBH intervention, respectively. Similar results were found for reading, where the mean difference in change was 0.9 (95% CI 0.2 to 1.6; Cohen's d = 0.06) and 1.1 (95% CI 0.3 to 1.9; Cohen's d = 0.18) points in favour of students in the PAL and DWBH intervention, respectively. When conducting intention to treat analysis with imputed data the estimates were attenuated and some no longer significant., Conclusion: The ScIM study demonstrates that two different school-based PA interventions providing approximately 120 min of additional PA weekly over nine months, significantly improved numeracy and reading performance in 14-year old students compared with controls. However, the results should be interpreted with caution as the effect sizes reported were very small or small and the estimates were attenuated when conducting intention to treat analysis. Despite this, our results are still positive and suggest that PA interventions are viable models to increase academic performance among adolescents., Trial Registration: Retrospectively registered (25/01/2019): NCT03817047 .

Background and Aims: The associations between aerobic fitness and traditional measures of lipid metabolism in children are uncertain. We investigated whether higher levels of aerobic fitness benefit lipoprotein metabolism by exploring associations with a comprehensive lipoprotein particle profile., Methods: In our prospective cohort study, we used targeted proton nuclear magnetic resonance ( 1 H NMR) spectroscopy to profile 57 measures of lipoprotein metabolism from fasting serum samples of 858 fifth-grade Norwegian schoolchildren (49.0% girls; mean age 10.0 years). Aerobic fitness was measured using an intermittent shuttle run aerobic fitness test. We used multiple linear regression adjusted for potential confounders to examine cross-sectional and prospective associations between aerobic fitness and lipoprotein particle profile., Results: Higher levels of aerobic fitness were associated with a favourable lipoprotein particle profile in the cross-sectional analysis, which included inverse associations with all measures of very low-density lipoprotein (VLDL) particles (e.g., -0.06 mmol·L -1 or -0.23 SD units; 95% CI = -0.31, -0.16 for VLDL cholesterol concentration). In the prospective analysis, the favourable pattern of associations persisted, though the individual associations tended to be more consistent with those of the cross-sectional analysis for the VLDL subclass measures compared to the low-density lipoproteins and high-density lipoproteins. Adjustment for adiposity attenuated the associations in both cross-sectional and prospective models. Nevertheless, an independent effect of aerobic fitness remained for some measures., Conclusions: Improving children's aerobic fitness levels should benefit lipoprotein metabolism, though a concomitant reduction in adiposity would likely potentiate this effect., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: A large majority of primary school pupils fail to achieve 30-min of daily, in-school moderate-to-vigorous physical activity (MVPA). The aim of this study was to investigate MVPA accumulation and subject frequency during academic lesson segments and the broader segmented school day., Methods: 122 children (42.6% boys; 9.9 ± 0.3 years) from six primary schools in North East England, wore uniaxial accelerometers for eight consecutive days. Subject frequency was assessed by teacher diaries. Multilevel models (children nested within schools) examined significant predictors of MVPA across each school-day segment (lesson one, break, lesson two, lunch, lesson three)., Results: Pupils averaged 18.33 ± 8.34 min of in-school MVPA, and 90.2% failed to achieve the in-school 30-min MVPA threshold. Across all school-day segments, MVPA accumulation was typically influenced at the individual level. Lessons one and two-dominated by maths and English-were less active than lesson three. Break and lunch were the most active segments., Conclusion: This study breaks new ground, revealing that MVPA accumulation and subject frequency varies greatly during different academic lessons. Morning lessons were dominated by the inactive delivery of maths and English, whereas afternoon lessons involved a greater array of subject delivery that resulted in marginally higher levels of MVPA.

Background: Physical activity (PA) declines throughout adolescence, therefore PA promotion during this period is important. We analyzed the effect of two school-based PA interventions on daily PA levels, cardiorespiratory fitness (CRF) and muscle strength among adolescents., Methods: For the nine-month School in Motion intervention study (ScIM), we cluster-randomized 30 Norwegian secondary schools (N = 2084, mean age [SD] = 14 [0.3] years) to one of three study arms. The physically active learning (PAL) intervention included 30 min physically active learning, 30 min PA and a 60 min physical education (PE) lesson per week. The Don't worry-Be happy (DWBH) intervention included a 60 min PA lesson and a 60 min PE lesson per week, both tailored to promote friendships and wellbeing. Both intervention arms were designed to engage the adolescents in 120 min of PA per week in addition to recess and mandatory PE lessons. The control group continued as per usual, including the standard amount of mandatory PE. PA (main outcome) was assessed by accelerometers, CRF and muscle strength (secondary outcomes) were assessed by an intermittent running test and selected tests from the Eurofit test battery., Results: Daily PA and time spent in moderate- to vigorous-intensity PA (MVPA) decreased in all groups throughout the intervention. The mean difference in PA level and MVPA for participants in the PAL-intervention arm was 34.7 cpm (95% CI: 4.1, 65.3) and 4.7 min/day (95% CI: 0.6, 8.8) higher, respectively, compared to the control arm. There were no significant intervention effects on daily PA level, MVPA or time spent sedentary for adolescents in the DWBH-intervention arm. Adolescents in the PAL-intervention arm increased distance covered in the running test compared to controls (19.8 m, 95% CI: 10.4, 29.1), whilst a negative intervention effect was observed among adolescents in the DWBH-intervention arm (- 11.6 m, 95% CI: - 22.0, - 1.1)., Conclusion: The PAL-intervention resulted in a significantly smaller decrease in daily PA level, time spent in MVPA, and increased CRF compared to controls. Our results indicate that a teacher-led intervention, including three unique intervention components, is effective in curbing the decline in PA observed across our cohort and improving CRF., Trial Registration: ClinicalTrials.gov ID nr: NCT03817047 . Registered 01/25/2019 'retrospectively registered'.

Objectives: Low and high birth weight is associated with higher levels of cardiometabolic risk factors and adiposity in children and adolescents, and increases the risk of cardiovascular diseases, obesity, and early mortality later in life. Moderate-to-vigorous physical activity (MVPA) is associated with lower cardiometabolic risk factors and may mitigate the detrimental consequences of high or low birth weight. Thus, we examined whether MVPA modified the associations between birth weight and cardiometabolic risk factors in children and adolescents., Methods: We used pooled individual data from 12 cohort- or cross-sectional studies including 9,100 children and adolescents. Birth weight was measured at birth or maternally reported retrospectively. Device-measured physical activity (PA) and cardiometabolic risk factors were measured in childhood or adolescence. We tested for associations between birth weight, MVPA, and cardiometabolic risk factors using multilevel linear regression, including study as a random factor. We tested for interaction between birth weight and MVPA by introducing the interaction term in the models (birth weight x MVPA)., Results: Most of the associations between birth weight (kg) and cardiometabolic risk factors were not modified by MVPA (min/day), except between birth weight and waist circumference (cm) in children (p = 0.005) and HDL-cholesterol (mmol/l) in adolescents (p = 0.040). Sensitivity analyses suggested that some of the associations were modified by VPA, i.e., the associations between birth weight and diastolic blood pressure (mmHg) in children (p = 0.009) and LDL- cholesterol (mmol/l) (p = 0.009) and triglycerides (mmol/l) in adolescents (p = 0.028)., Conclusion: MVPA appears not to consistently modify the associations between low birth weight and cardiometabolic risk. In contrast, MVPA may mitigate the association between higher birth weight and higher waist circumference in children. MVPA is consistently associated with a lower cardiometabolic risk across the birth weight spectrum. Optimal prenatal growth and subsequent PA are both important in relation to cardiometabolic health in children and adolescents.

Introduction: There is a dearth of high-quality evidence on effective, sustainable, and scalable interventions to increase physical activity (PA) and concomitant outcomes in preschoolers. Specifically, there is a need to better understand how the preschool context can be used to increase various types of physically active play to promote holistic child development. The implementation of such interventions requires highly competent preschool staffs, however, the competence in promoting PA is often low. The main aim of the ACTNOW study is therefore to investigate the effects of professional development for preschool staffs on child PA and developmental outcomes., Methods: The study will be conducted in Norway 2019-2022 and is designed as a two-arm (intervention, control) cluster randomized controlled trial (RCT) with 7- and 18-months follow-ups. We aim to recruit 60 preschools and 1,200 3- to 5-years-old children to provide sufficient power to detect effect sizes (ESs) between 0.20 and 0.30. The intervention is nested within two levels: the preschool and the child. Central to the ACTNOW intervention are opportunities for children to engage in a variety of "enriched," meaningful, and enjoyable physically active play that supports the development of the whole child. To this end, the main intervention is a 7-month professional development/education module for preschool staff, aimed to provide them with the necessary capacity to deliver four core PA components to the children (moderate-to-vigorous PA, motor-challenging PA, cognitively engaging play, and physically active learning). We will include a range of child-level outcomes, including PA, physical fitness, adiposity, motor skills, socioemotional health, self-regulation, executive function, and learning. At the preschool level, we will describe implementation and adaptation processes using quantitative and qualitative data., Discussion: Professional development of staff and a whole-child approach that integrates PA with cognitively engaging play and learning activities in the preschool setting may provide a feasible vehicle to enhance both physical and cognitive development in young children. ACTNOW is designed to test this hypothesis to provide a sustainable way to build human capital and provide an early solution to lifelong public health and developmental challenges., Clinical Trial Registration: www.ClinicalTrials.gov identifier NCT04048967., (Copyright © 2020 Aadland, Tjomsland, Johannessen, Nilsen, Resaland, Glosvik, Lykkebø, Stokke, Andersen, Anderssen, Pfeiffer, Tomporowski, Størksen, Bartholomew, Ommundsen, Howard, Okely and Aadland.)

Background: UK and global policies recommend whole-school approaches to improve childrens' inadequate physical activity (PA) levels. Yet, recent meta-analyses establish current interventions as ineffective due to suboptimal implementation rates and poor sustainability. To create effective interventions, which recognise schools as complex adaptive sub-systems, multi-stakeholder input is necessary. Further, to ensure 'systems' change, a framework is required that identifies all components of a whole-school PA approach. The study's aim was to co-develop a whole-school PA framework using the double diamond design approach (DDDA)., Methodology: Fifty stakeholders engaged in a six-phase DDDA workshop undertaking tasks within same stakeholder (n = 9; UK researchers, public health specialists, active schools coordinators, headteachers, teachers, active partner schools specialists, national organisations, Sport England local delivery pilot representatives and international researchers) and mixed (n = 6) stakeholder groupings. Six draft frameworks were created before stakeholders voted for one 'initial' framework. Next, stakeholders reviewed the 'initial' framework, proposing modifications. Following the workshop, stakeholders voted on eight modifications using an online questionnaire., Results: Following voting, the Creating Active Schools Framework (CAS) was designed. At the centre, ethos and practice drive school policy and vision, creating the physical and social environments in which five key stakeholder groups operate to deliver PA through seven opportunities both within and beyond school. At the top of the model, initial and in-service teacher training foster teachers' capability, opportunity and motivation (COM-B) to deliver whole-school PA. National policy and organisations drive top-down initiatives that support or hinder whole-school PA. To the authors' knowledge, this is the first time practitioners, policymakers and researchers have co-designed a whole-school PA framework from initial conception. The novelty of CAS resides in identifying the multitude of interconnecting components of a whole-school adaptive sub-system; exposing the complexity required to create systems change. The framework can be used to shape future policy, research and practice to embed sustainable PA interventions within schools. To enact such change, CAS presents a potential paradigm shift, providing a map and method to guide future co-production by multiple experts of PA initiatives 'with' schools, while abandoning outdated traditional approaches of implementing interventions 'on' schools.

When analysing physical activity (PA) levels using accelerometry, the epoch setting is critical to capture intensity-specific PA correctly. The aim of the present study was to investigate the PA intensity signatures related to metabolic health in children using different epoch settings. A sample of 841 Norwegian children (age 10.2 ± 0.3 years; BMI 18.0 ± 3.0; 50% boys) provided data on accelerometry (ActiGraph GT3X+) and several indices of metabolic health (aerobic fitness, abdominal fatness, insulin sensitivity, lipid metabolism, blood pressure) that were used to create a composite metabolic health score. We created intensity spectra from 0-99 to ≥ 10000 counts per minute (cpm) for files aggregated using 1, 10, and 60-second epoch periods and used multivariate pattern analysis to analyse the data. The association patterns with metabolic health differed substantially between epoch settings. The intensity intervals most strongly associated with metabolic health were 7000-8000 cpm for data analysed using 1-second epoch, 5500-6500 cpm for data analysed using 10-second epoch, and 4000-5000 cpm analysed using 60-second epoch. Aggregation of data over different epoch periods has a clear impact on how PA intensities in the moderate and vigorous range are associated with childhood metabolic health.

The purpose of this study was to examine the changes in physical activity (PA), physical fitness and psychosocial well-being in early adolescents following implementation of a school-based health promotion program in secondary schools., Methods: Six municipalities in Telemark County, Norway, were recruited into intervention (6 schools) or control groups (9 schools). A total of 644 pupils participated in the study (response rate: 79%). The schools in the intervention group implemented the Active and Healthy Kids program, where the PA component consisted of (1) 120 min/week of physically active learning (PAL) and (2) 25 min/week of physical active breaks. Furthermore, both the intervention and control schools carried out 135 min/week of physical education. The primary outcome was PA. Secondary outcomes were sedentary time, physical fitness, subjective vitality and health-related quality of life (HRQoL) in five domains: physical health, psychological well-being, parent, peers and school., Results: There was a group x time effect on school-based PA ( p < 0.05), but not total PA, as well as on physical fitness ( p < 0.05) and vitality (p < 0.01). In girls, there also was a group x time effect on three out of the five domains on HRQoL ( p < 0.05)., Conclusions: A multi-component, school-based health-promotion program with emphasis on the use of PAL led to positive changes in school-based PA levels. Furthermore, positive changes were seen in physical fitness, vitality and HRQoL among early adolescents in a county with a poor public health profile. This might have implications for the development and promotion in schools of general health and well-being throughout adolescence., Competing Interests: The authors declare no conflict of interest.

The onset of cardiometabolic diseases are recognized to occur in childhood. We aimed to investigate the effect of a school-based cluster-randomized controlled trial of physical activity (PA) on single and clustered cardiometabolic risk factors. We included 1129 fifth-grade children from 57 schools (≥seven children in each class) in Sogn and Fjordane County, Norway, randomized to 28 intervention schools and 29 control schools. The PA intervention was conducted between November 2014 and June 2015. Cardiometabolic risk factors were waist circumference (WC), systolic blood pressure (SBP), total cholesterol (TC):high-density lipoprotein (HDL)-ratio, triglycerides (TG), homeostatic model assessment (HOMA)-score, and cardiorespiratory fitness (CRF). PA was measured by accelerometry. No significant intervention effects were found for single or clustered cardiometabolic risk factors. However, in children with the less favorable baseline values, beneficial effects were found for SBP (p = 0.07 for group ∗ tertile interaction), TC:HDL ratio (p = 0.03 for group ∗ tertile interaction) and the clustered cardiometabolic risk score (p = 0.01 for group ∗ tertile interaction). Compared to boys, girls had a greater effect of the intervention on WC (p = 0.03 for group ∗ sex interaction) and CRF (p < 0.001 for group ∗ sex interaction). The majority of the children had high PA levels, thus limited potential for change, and we found no effects of the PA intervention on cardiometabolic risk in the total sample. However, the intervention had a significantly enhanced effect on fatness and fitness of girls compared to boys. Furthermore, the data suggest that children with the least favorable cardiometabolic risk profile and therefore most in need of change can benefit from school-based PA interventions. Trial registration number: Clinicaltrials.gov ID no.: NCT02132494., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To identify co-produced multi-stakeholder perspectives important for successful widespread physically active learning (PAL) adoption and implementation., Methods: A total of 35 stakeholders (policymakers n  = 9; commercial education sector, n  = 8; teachers, n  = 3; researchers, n  = 15) attended a design thinking PAL workshop. Participants formed 5 multi-disciplinary groups with at least 1 representative from each stakeholder group. Each group, facilitated by a researcher, undertook 2 tasks: (1) using Post-it Notes, the following question was answered: within the school day, what are the opportunities for learning combined with movement? and (2) structured as a washing-line task, the following question was answered: how can we establish PAL as the norm? All discussions were audio-recorded and transcribed. Inductive analyses were conducted by 4 authors. After the analyses were complete, the main themes and subthemes were assigned to 4 predetermined categories: (1) PAL design and implementation, (2) priorities for practice, (3) priorities for policy, and (4) priorities for research., Results: The following were the main themes for PAL implementation: opportunities for PAL within the school day, delivery environments, learning approaches, and the intensity of PAL. The main themes for the priorities for practice included teacher confidence and competence, resources to support delivery, and community of practice. The main themes for the policy for priorities included self-governance, the Office for Standards in Education, Children's Services, and Skill, policy investment in initial teacher training, and curriculum reform. The main themes for the research priorities included establishing a strong evidence base, school-based PAL implementation, and a whole-systems approach., Conclusion: The present study is the first to identify PAL implementation factors using a combined multi-stakeholder perspective. To achieve wider PAL adoption and implementation, future interventions should be evidence based and address implementation factors at the classroom level (e.g., approaches and delivery environments), school level (e.g., communities of practice), and policy level (e.g., initial teacher training)., (© 2019 Published by Elsevier B.V. on behalf of Shanghai University of Sport.)

Purpose: The use of uniaxial summary measures from accelerometry (i.e., counts per minute or minutes spent in moderate-to-vigorous intensity) substantially restricts information about physical activity (PA), and is probably a result of reliance on analytic approaches that cannot handle collinear variables. In the present study, we aimed to determine the multivariate triaxial PA intensity signature related to metabolic health in children, by investigating associations of the whole spectra of PA intensities from all axes using multivariate pattern analysis., Methods: We included 841 children (age, 10.2 ± 0.3 yr; body mass index, 18.0 ± 3.0; 50% boys) from the Active Smarter Kids study conducted in Norway 2014 to 2015 providing valid data on accelerometry (ActiGraph GT3X+) and several indices of metabolic health (aerobic fitness, abdominal fatness, insulin sensitivity, lipid metabolism, blood pressure) that were used to create a composite metabolic health score. We created intensity spectra from 0 to 100 to ≥10,000 counts per minute for separate axes and used multivariate pattern analysis to analyze the data., Results: The explained variance of metabolic health was 3.2% for counts per minute from the vertical axis, 17.0% for the vertical axis intensity spectrum, and 29.5% for the full model including all axes. Thus, including full triaxial intensity spectra improved the model for metabolic health tenfold compared with using overall PA (counts per minute) from the vertical axis only. The intensity signature associated with metabolic health differed across the axes., Conclusions: Our findings show that the three different axes carry distinct information about children's PA and the relation of PA to their health and demonstrate a great potential for triaxial accelerometry and a multivariate analytic approach to advance the field of PA epidemiology.

Background and Aims: Physical activity is favourably associated with certain markers of lipid metabolism. The relationship of physical activity with lipoprotein particle profiles in children is not known. Here we examine cross-sectional associations between objectively measured physical activity and sedentary time with serum markers of lipoprotein metabolism., Methods: Our cohort included 880 children (49.0% girls, mean age 10.2 years). Physical activity intensity and time spent sedentary were measured objectively using accelerometers. 30 measures of lipoprotein metabolism were quantified using nuclear magnetic resonance spectroscopy. Multiple linear regression models adjusted for age, sex, sexual maturity and socioeconomic status were used to determine associations of physical activity and sedentary time with lipoprotein measures. Additional models were adjusted for adiposity. Isotemporal substitution models quantified theoretical associations of replacing 30 min of sedentary time with 30 min of moderate- to vigorous-intensity physical activity (MVPA)., Results: Time spent in MVPA was associated with a favourable lipoprotein profile independent of sedentary time. There were inverse associations with a number of lipoprotein measures, including most apolipoprotein B-containing lipoprotein subclasses and triglyceride measures, the ratio of total to high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol concentration. There were positive associations with larger HDL subclasses, HDL cholesterol concentration and particle size. Reallocating 30 min of sedentary time to MVPA had broadly similar associations. Sedentary time was only partly and weakly associated with an unfavourable lipoprotein profile., Conclusions: Physical activity of at least moderate-intensity is associated with a favourable lipoprotein profile in schoolchildren, independent of time spent sedentary, adiposity and other confounders., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: The analysis of associations between accelerometer-derived physical activity (PA) intensities and cardiometabolic health is a major challenge due to multicollinearity between the explanatory variables. This challenge has facilitated the application of different analytic approaches within the field. The aim of the present study was to compare association patterns of PA intensities with cardiometabolic health in children obtained from multiple linear regression, compositional data analysis, and multivariate pattern analysis., Methods: A sample of 841 children (age 10.2 ± 0.3 years; BMI 18.0 ± 3.0; 50% boys) provided valid accelerometry and cardiometabolic health data. Accelerometry (ActiGraph GT3X+) data were characterized into traditional (four PA intensity variables) and more detailed categories (23 PA intensity variables covering the intensity spectrum; 0-99 to ≥10,000 counts per minute). Several indices of cardiometabolic health were used to create a composite cardiometabolic health score. Multiple linear regression and multivariate pattern analyses were used to analyze both raw and compositional data., Results: Besides a consistent negative (favorable) association between vigorous PA and the cardiometabolic health measure using the traditional description of PA data, associations between PA intensities and cardiometabolic health differed substantially depending on the analytic approaches used. Multiple linear regression lead to instable and spurious associations, while compositional data analysis showed distorted association patterns. Multivariate pattern analysis appeared to handle the raw PA data correctly, leading to more plausible interpretations of the associations between PA intensities and cardiometabolic health., Conclusions: Future studies should consider multivariate pattern analysis without any transformation of PA data when examining relationships between PA intensity patterns and health outcomes., Trial Registration: The study was registered in Clinicaltrials.gov 7th of April 2014 with identification number NCT02132494 .

Objective: To investigate cardiometabolic risk factor levels in a group of Norwegian 10-year-old children compared to international values and examine the association between cardiorespiratory fitness (CRF) and the reference-standardized clustered risk score., Methods: 913 children (49% girls) were included from the Active Smarter Kids (ASK) study. Body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) to HDL-C ratio, triglyceride (TG), glucose, insulin, homeostatic model assessment (HOMA) score and CRF, were standardized according to international age-and sex-specific reference values., Results: The Norwegian children had significantly more favorable WC, DBP, glucose, HDL-C and CRF levels compared to the international reference values, but similar or less favorable levels of other cardiometabolic risk factors. CRF was the variable that differed the most from the international values (mean (95% CI) 1.20 (1.16 to 1.24) SD). The clustered risk score (excluding CRF) was higher in the Norwegian children, but decreased to below international levels when including CRF (mean (95% CI) - 0.08 (- 0.12 to -0.05) SD). CRF had a significant inverse association with the clustered risk score (excluding CRF) (β - 0.37 SD, 95% CI -0.43 to -0.31)., Conclusions: Norwegian children have substantially higher CRF levels than international standards, and including CRF in clustered risk scores reduces overall risk in Norwegian children below that of international levels. CRF is associated with improved cardiometabolic health in children., Competing Interests: The authors have declared that no competing interests exist.

Associations between multicollinear accelerometry-derived physical activity (PA) data and cardiometabolic health in children needs to be analyzed using an approach that can handle collinearity among the explanatory variables. The aim of this paper is to provide readers a tutorial overview of interpretation of multivariate pattern analysis models using PA accelerometry data that reveals the associations to cardiometabolic health. A total of 841 children (age 10.2 ± 0.3 years) provided valid data on accelerometry (ActiGraph GT3X+) and six indices of cardiometabolic health that were used to create a composite score. We used a high-resolution PA description including 23 intensity variables covering the intensity spectrum (from 0-99 to ≥10000 counts per minute), and multivariate pattern analysis to analyze data. We report different statistical measures of the multivariate associations between PA and cardiometabolic health and use decentile groups of PA as a basis for discussing the meaning and impact of multicollinearity. We show that for high-resolution accelerometry data; considering all explanatory variables is crucial to obtain a correct interpretation of associations to cardiometabolic health; which is otherwise strongly confounded by multicollinearity in the dataset. Thus; multivariate pattern analysis challenges the traditional interpretation of findings from linear regression models assuming independent explanatory variables.

The purpose of this study was to investigate the effect of different band-pass filters on the measurement bias with ActiGraph counts during high speed running and for estimating free-living vigorous physical activity (VPA). Two alternative band-pass filters were designed, extending the original frequency range from 0·29 to 1·66 Hz (AG) to 0·29-4 Hz (AC4) and 0·29-10 Hz (AC10). Sixty-two subjects in three age groups participated in a structured locomotion protocol consisting of multiple walking and running speeds. The time spent in free-living VPA using the three different band-pass filters were evaluated in 1121 children. Band-pass filter specific intensity cut-points from both linear regression and ROC analysis was identified from a calibration experiment using indirect calorimetry. The ActiGraph GT3X+ device recording raw acceleration at 30 Hz was used in all experiments. The linear association between counts and running speed was negative for AG but positive for AC4 and AC10 across all age groups. The time spent in free-living VPA was similar for all band-pass filters. Considering higher frequency information in the generation of ActiGraph counts with a hip/waist worn device reduces the measurement bias with running above 10 km·h -1 . However, additional developments are required to accurately capture all VPA, including intermittent activities., (© 2019 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

The preschool environment exerts an important influence on children's behaviour, including physical activity (PA). However, information is lacking regarding where and when most of children's PA is undertaken. This study aimed to describe PA and sedentary time (SED) during preschool hours and time out-of-care, and on weekdays and weekend days, and to investigate differences in PA patterns according to sex, age, and MVPA levels. From September 2015 to June 2016, we measured PA levels of 1109 children (age range, 2.7-6.5 years; mean age 4.7 years; boys, 52%) using ActiGraph GT3X+ accelerometers for up to 14 consecutive days. We applied a linear mixed model to analyse associations and interactions between total PA (counts per minute [cpm]), light PA (LPA), moderate-to-vigorous PA (MVPA), SED, sex, age, and overall MVPA regardless of setting, during preschool hours versus time out-of-care, and on weekdays versus weekend days. Children undertook more PA and less SED on weekdays compared to weekend days (p < 0.01). For boys, MVPA levels were higher during preschool hours than during time out-of-care (p < 0.05). Differences in total PA and MVPA between preschool hours versus time out-of-care, and between weekdays and weekend days, were greater in boys, older children, and highly active children than in girls, younger children, and children with lower overall MVPA levels (p < 0.01). The preschool arena is important for children's PA. Concerning MVPA, this study showed that boys, older children, and highly active children benefit more from this environment compared to girls, younger preschoolers, and children with lower MVPA levels.

Aim: This study investigated children's physical activity (PA) preferences, as these can aid the design of school-based interventions., Methods: Data were collected in 2014 as a part of the Active Smarter Kids study and 1026 students (52% boys) from 57 Norwegian primary schools completed a questionnaire about their favourite physical activities at a mean age of 10.2 ± 0.3 years. We identified five patterns of PA and studied whether gender, cardiorespiratory fitness and abdominal adiposity were associated with these patterns., Results: Soccer and slalom skiing were the favourite activities, and the most pronounced gender differences were for activities favoured by girls, which included dancing, gymnastics, exercising to music and jumping rope (p < 0.001). When the five component patterns were analysed using linear mixed-effect models, this showed a strong female preference for dancing, gymnastics, exercising to music and climbing. Cardiovascular fitness was negatively associated with frisbee, dodgeball, baseball and floorball, and positively associated with team handball, volleyball and basketball and with slalom skiing and cross-country skiing. It was interesting that the children's preferences were not related to their abdominal adiposity., Conclusion: The results showed different gender-based PA preferences and positive and negative associations with cardiovascular fitness, but no relationship with abdominal adiposity., (©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Aerobic fitness is an apparent candidate for screening children and youth for poor cardiometabolic health and future risk of cardiovascular disease (CVD). Yet, age- and sex-specific cut points for children and youth determined using a maximal protocol and directly measured peak oxygen consumption (VO 2peak ) does not exist. We used a nationally representative sample of 1462 Norwegian children and youth (788 boys and 674 girls aged 8.7-10.4 years and 14.7-16.7 years) who in 2005-2006 performed a maximal cycle ergometer test with direct measurement of VO 2peak , along with measurement of several other risk factors for CVD (systolic blood pressure, waist circumference:height ratio, total:high-density lipoprotein cholesterol ratio, triglycerides, Homeostasis Model Assessment for Insulin Resistance). Based on the proportion of children having clustering (least favorable quartile) of 6 (1.6%), ≥5 (5.2%), and ≥4 (10.6%) CVD risk factors, we established the 2nd, 5th, and 10th percentile cut points for VO 2peak (mL/kg/min) for children and youth aged 8-18 years. Classification accuracy was determined using the Kappa coefficient (k), sensitivity, and specificity. For boys, the 2nd, 5th, and 10th percentile VO 2peak cut points were 33.6-36.4, 36.3-39.8, and 38.7-43.0 mL/kg/min, respectively. For girls, the corresponding cut points were 29.7-29.1, 32.4-31.4, and 34.8-33.5 mL/kg/min Together with BMI, but without more invasive measures of traditional risk factors for CVD, these cut points can be used to screen schoolchildren for poor cardiometabolic health with moderate discriminating ability (k ≤ 0.53)., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Sedentary time and moderate-to-vigorous physical activity (MVPA) may be uniquely related to cardiometabolic health. Excessive sedentary time is suggested as an independent cardiometabolic risk factor, while MVPA is favourably associated with cardiometabolic health. This systematic review and meta-analysis summarizes the evidence on a prospective relationship between objectively measured sedentary time, MVPA and cardiometabolic health indicators in youth. PubMed, Embase, CINAHL, PhyscINFO and SPORTDiscus were systematically searched from January 2000 until April 2018. Studies were included if sedentary time and physical activity were measured objectively and examined associations with body mass index, waist circumference, triglycerides, high-density lipoprotein, insulin, blood pressure or the clustering of these cardiometabolic risk factors. We identified 30 studies, of which 21 were of high quality. No evidence was found for an association between sedentary time and cardiometabolic outcomes. The association between MVPA and individual cardiometabolic risk factors was inconsistent. The meta-analysis for prospective studies found a small but significant effect size between MVPA at baseline and clustered cardiometabolic risk at follow-up (ES -0.014 [95% CI, -0.024 to -0.004]). We conclude that there is no prospective association between sedentary time and cardiometabolic health, while MVPA is beneficially associated with cardiometabolic health in youth., (© 2018 World Obesity Federation.)

We investigated whether a seven-month (November 2014 to June 2015), school-based cluster-randomized controlled physical activity intervention improved health-related quality of life (HRQoL) in 10-year old children. The participants ( N  = 1229) from 57 elementary schools in Sogn og Fjordane County, Norway, were cluster-randomized by school either to the intervention (I) or control (C) group. The planned intervention in the 28 I-schools was 300 min of physical activity per week, compared to 135 min in the 29C-schools. HRQoL was assessed by self-report, using the Kidscreen-27 questionnaire. Objectively measured physical activity did not differ between the I-schools and C-schools during the intervention. No effect of the intervention was found for HRQoL: Physical well-being ( P  = 0.789), Psychological well-being ( P  = 0.682), Autonomy & parents ( P  = 0.662), Social support & peers ( P  = 0.828) and School environment ( P  = 0.074). In conclusion, the ASK school-based physical activity intervention showed no significant effect on HRQoL.