Active Smarter Kids (ASK): Rationale and design of a cluster-randomized controlled trial investigating the effects of daily physical activity on children's academic performance and risk factors for non-communicable diseases

An approach to determine the net predictive multivariate association pattern between cardiorespiratory fitness and a high-resolution physical activity spectrum in the presence of multicollinear covariates

Multivariate pattern analysis was recently extended with covariate projections to solve the challenging task of modelling and interpreting associations in the presence of linear dependent multivariate covariates. Within a joint model, this approach allows quantification of the net association pattern between the outcome and the explanatory variables and between the individual covariates and these variables. The aim of this paper is to apply this methodology to establish the net multivariate association pattern between cardiorespiratory fitness (CRF) and a high-resolution linear dependent physical activity (PA) intensity descriptor derived from accelerometry in children and to validate the crucial sub-regions in the PA spectrum predicting CRF. We applied the Andersen test as a measure of CRF, a PA descriptor with 23 PA intensities, and included age, sex, and three nearly linear dependent measures of adiposity as covariates. Net predictive association patterns are calculated for unadjusted and adjusted data. The explained variance in CRF was reduced from 25% for unadjusted data to 7.2% for adjusted data, but the association pattern was robust and dominated by vigorous PA across models. Models of sub-regions of the PA spectrum validated the association pattern for the full model and the crucial influence of vigorous PA.

Device-measured physical activity and sedentary time in the Nordic countries: A scoping review of population-based studies

PURPOSE

The purpose of this scoping review was to summarize and describe the methodology and results from population-based studies of physical activity and sedentary time measured with devices in the Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) and published in 2000 or later.

METHODS

A systematic search was carried out in PubMed and Web of Science in June 2023 using predefined search terms.

RESULTS

Fourteen unique research projects or surveillance studies were identified. Additionally, 2 surveillance studies published by national agencies were included, resulting in a total of 16 studies for inclusion. National surveillance systems exist in Finland and Norway, with regular survey waves in school-aged children/adolescents and adults. In Denmark, recent nationally representative data have been collected in school children only. So far, Sweden has no regular national surveillance system using device-based data collection. No studies were found from Iceland. The first study was conducted in 2001 and the most recent in 2022, with most data collected from 2016 to date. Five studies included children/adolescents 6-18 years, no study included preschoolers. In total 11 studies included adults, of which 8 also covered older adults. No study focused specifically on older adults. The analytical sample size ranged from 205 to 27,890. Detailed methodology is presented, such as information on sampling strategy, device type and placement, wear protocols, and physical activity classification schemes. Levels of physical activity and sedentary time in children/adolescents, adults, and older adults across the Nordic countries are presented.

CONCLUSION

A growing implementation of device-based population surveillance of physical activity and sedentary behavior in the Nordic countries has been identified. The variety of devices, placement, and data procedures both within and between the Nordic countries highlights the challenges when it comes to comparing study outcomes as well as the need for more standardized data collection.

Study protocol for the ACTIVE SCHOOL study investigating two different strategies of physical activity to improve academic performance in Schoolchildren

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.

Multivariate pattern analysis: a method and software to reveal, quantify, and visualize predictive association patterns in multicollinear data

BACKGROUND

Strongly multicollinear covariates, such as those typically represented in metabolomics applications, represent a challenge for multivariate regression analysis. These challenges are commonly circumvented by reducing the number of covariates to a subset of linearly independent variables, but this strategy may lead to loss of resolution and thus produce models with poorer interpretative potential. The aim of this work was to implement and illustrate a method, multivariate pattern analysis (MVPA), which can handle multivariate covariates without compromising resolution or model quality.

RESULTS

MVPA has been implemented in an open-source R package of the same name, mvpa. To facilitate the usage and interpretation of complex association patterns, mvpa has also been integrated into an R shiny app, mvpaShiny, which can be accessed on www.mvpashiny.org . MVPA utilizes a general projection algorithm that embraces a diversity of possible models. The method handles multicollinear and even linear dependent covariates. MVPA separates the variance in the data into orthogonal parts within the frame of a single joint model: one part describing the relations between covariates, outcome, and explanatory variables and another part describing the "net" predictive association pattern between outcome and explanatory variables. These patterns are visualized and interpreted in variance plots and plots for pattern analysis and ranking according to variable importance. Adjustment for a linear dependent covariate is performed in three steps. First, partial least squares regression with repeated Monte Carlo resampling is used to determine the number of predictive PLS components for a model relating the covariate to the outcome. Second, postprocessing of this PLS model by target projection provided a single component expressing the predictive association pattern between the outcome and the covariate. Third, the outcome and the explanatory variables were adjusted for the covariate by using the target score in the projection algorithm to obtain "net" data. We illustrate the main features of MVPA by investigating the partial mediation of a linearly dependent metabolomics descriptor on the association pattern between a measure of insulin resistance and lifestyle-related factors.

CONCLUSIONS

Our method and implementation in R extend the range of possible analyses and visualizations that can be performed for complex multivariate data structures. The R packages are available on github.com/liningtonlab/mvpa and github.com/liningtonlab/mvpaShiny.

Classroom-Based Physical Activity as a Means to Improve Self-Efficacy and Academic Achievement among Normal-Weight and Overweight Youth

Although physical activity has positive physical and mental health outcomes, particularly among adolescents, a significant percentage of young people maintain a largely sedentary lifestyle. Considering that the youths spend the greater part of the day at school, this is considered an ideal setting to foster active and healthy living. Consequently, this study is intended to investigate the connection between physical activity, self-efficacy and academic achievement in normal-weight and overweight adolescents. In total, 100 students (aged 14-15) from a public high school placed in the south of Italy were enrolled. They participated either in a 12-week classroom-based physical activity break program performed during science classes (60'/2 days per week) in which a nutritional educational program was carried out or in regular science lessons (60'/2 days per week). At the beginning and end of the intervention programs, a set of standardized motor evaluation tests (standing long jump test, Harvard step test, push up, sit and reach test), the scholastic self-efficacy test and the Amos 8-15 were administered. As a result, a meaningful Time × Group interaction for the self-efficacy variable and Amos 8-15 was observed in the intervention group. Specifically, they reported significant improvement in study skills, motivational factors, concentration and self-efficacy, as well as a decrease in anxiety and BMI (p < 0.001). No significant change was observed in the control group. The conclusions of this research underpin the notion that classroom-based physical activity break is a successful approach for enhancing students' psycho-physical well-being, as well as academic achievement.

An approach to assess and adjust for the influence of multicollinear covariates on metabolomics association patterns-applied to a study of the associations between a comprehensive lipoprotein profile and the homeostatic model assessment of insulin resistance

INTRODUCTION

Comprehensive lipoprotein profiling using proton nuclear magnetic resonance (NMR) spectroscopy of serum represents an alternative to the homeostatic model assessment of insulin resistance (HOMA-IR). Both adiposity and physical (in)activity associate to insulin resistance, but quantification of the influence of these two lifestyle related factors on the association pattern of HOMA-IR to lipoproteins suffers from lack of appropriate methods to handle multicollinear covariates.

OBJECTIVES

We aimed at (i) developing an approach for assessment and adjustment of the influence of multicollinear and even linear dependent covariates on regression models, and (ii) to use this approach to examine the influence of adiposity and physical activity on the association pattern between HOMA-IR and the lipoprotein profile.

METHODS

For 841 children, lipoprotein profiles were obtained from serum proton NMR and physical activity (PA) intensity profiles from accelerometry. Adiposity was measured as body mass index, the ratio of waist circumference to height, and skinfold thickness. Target projections were used to assess and isolate the influence of adiposity and PA on the association pattern of HOMA-IR to the lipoproteins.

RESULTS

Adiposity explained just over 50% of the association pattern of HOMA-IR to the lipoproteins with strongest influence on high-density lipoprotein features. The influence of PA was mainly attributed to a strong inverse association between adiposity and moderate and high-intensity physical activity.

CONCLUSION

The presented covariate projection approach to obtain net association patterns, made it possible to quantify and interpret the influence of adiposity and physical (in)activity on the association pattern of HOMA-IR to the lipoprotein features.

Evaluation of feasibility, effectiveness, and sustainability of school-based physical activity "active break" interventions in pre-adolescent and adolescent students: a systematic review

Objective

The present systematic review aimed to investigate the impact of school-based physical activity (PA) interventions of “active breaks” on PA levels, classroom behaviour, cognitive functions, and well-being in pre-adolescents and adolescents attending secondary and high school.

Methods

In March 2021, we performed a systematic research in CINAHL, Cochrane Library, Embase, MedLine, and PsycINFO databases and through grey literature. Quality assessment was performed in accordance with the Cochrane Tool for Quality Assessment for RCTs and the STROBE tool for observational studies. We included studies that investigated classroom PA interventions led by teachers such as active breaks or physically active lessons on PA levels, classroom behaviour, cognitive function, and quality of life in pre-adolescent and adolescent population attending secondary and high school.

Synthesis

Three studies met the inclusion criteria. Two studies showed a positive effect of active breaks on students’ classroom behaviour and quality of life. One study registered a positive effect in the increase in school PA levels; unfortunately, this effect was not found in the overall levels of PA or in the reduction of sedentary behaviour. All three studies showed the feasibility and acceptability of active breaks intervention in secondary and high school settings.

Conclusion

This systematic review suggests the potential benefit of this type of intervention integrated in the secondary and high school curriculum on classroom behaviour, school PA levels, and well-being.

Supplementary Information

The online version contains supplementary material available at 10.17269/s41997-022-00652-6.

Health and Academic Performance With Happy Children: A Controlled Longitudinal Study Based on the HOPP Project

Background

Overweight/obesity in children and adolescents, largely arising due to increased food intake and reduced physical activity, is a major health concern. Physical activity (PA) integrated into learning has been shown to not only lead to improved health outcomes and wellbeing but also positively affect academic performance. The Health and Academic Performance with Happy Children (HAPHC) project aims at enhancing health and academic performance in elementary school children via implementation of a daily unit of Physical Activity Across the Curriculum (PAAC), which is carried out within the school setting. In this project, PA as an integrated part of learning will be evaluated and the learning material adapted for a large scale implementation across several European countries.

Methods

In three European countries (Austria, Slovenia, and Belgium), 12 primary schools in total will be recruited to act as either intervention or control school in a large intervention study, which applies the PAAC pedagogy during lectures. It is estimated that, at least 3,000+ children across the three countries will be recruited in this study. All teachers of intervention schools will receive training and materials/teaching equipment that will allow them to integrate a daily PA unit of 45 min over 3 years across the curriculum. In response to the daily PA intervention, the following primary outcomes will be assessed: changes in health related physiological factors, academic achievement, psycho-social aspects and wellbeing.

Impact of Project

The HAPHC project aims at promoting public health by increasing PA at an early age within the school setting and therewith preventing the increasing risk of non-communicable diseases across Europe. HAPHC project aims to develop knowledge and materials, which will ensure that the PAAC can be scalable to other European countries.

Trial Registration Number

ClinicalTrials.gov, identifier: NCT04956003.

Equalisation of Children's Various Levels of Physical Activity Using Increased Physical Activity at School Among Ninth Graders

The purpose of this study was to examine whether 60 min of physical activity implemented during school hours, would have an impact on 15-year-olds' MVPA (moderate to vigorous physical activity) throughout the school day, and what effect it would have on low-, average-, and high- physically-active students. The intervention study included a sample of every 93 students in the ninth grade from a school in Trøndelag, Norway. Data on the students' physical activity levels during schooltime were measured using accelerometers and analyzed using the Actilife program. A significant higher change in MVPA was found in the intervention group compared to the control group, with an average increase of 25 min in MVPA in the pre-test to 42 min in post-test. Further analyses showed that the that both the low-active and the high-active had a significant increase in MVPA, taking the results of the control group into consideration. However, the low-active participants had the largest increase, with a 123% increase in MVPA during schooltime. The implication of the study is that PA interventions in school have the largest percentage effect among the low-active students in the study, which indicates that school-based interventions can be important in bridging social differences in MVPA among adolescents.

Giving Ideas Some Legs or Legs Some Ideas? Children's Motor Creativity Is Enhanced by Physical Activity Enrichment: Direct and Mediated Paths

Approaches to foster motor creativity differ according to whether creative movements are assumed to be enacted creative ideas, or solutions to emerging motor problems that arise from task and environmental constraints. The twofold aim of the current study was to investigate whether (1) an enriched physical education (PE) intervention delivered with a joint constraints-led and cognitive stimulation approach fosters motor creativity, and the responsiveness to the intervention is moderated by baseline motor and cognitive skills and sex; (2) the intervention may benefit motor creativity through gains in motor coordination, executive function, and creative thinking. Ninety-five children, aged 6-9 years, participated in a 6-month group randomized trial with specialist-led enriched PE vs. generalist-led conventional PE. Before and after the intervention, Bertsch's Test of Motor Creativity, Movement Assessment Battery for Children, Random Number Generation task and Torrance Test of Creative Thinking were administered. Linear mixed models were run accounting for the random effects of data clusters. Multiple mediation analysis was performed to assess whether motor coordination, executive function and creative thinking mediated any improvement of motor creativity. Results showed that (1) specialist-led enriched PE, compared to generalist-led conventional practice, elicited a more pronounced improvement in all motor creativity dimensions (fluency, flexibility, and originality) independently of baseline levels of motor and cognitive skills and sex; and (2) improved motor creativity was partially mediated by improved motor coordination and, as regards motor flexibility, also by improved inhibitory ability. In conclusion, enriching PE with tailored manipulations of constraints and variability may enhance the ability to create multiple and original task-pertinent movements both directly and through indirect paths. The results are discussed extending to motor creativity a theoretical framework that distinguishes different creativity modes. The intervention may have fostered the generation of creative movements directly through the exposure to variation in constraints, activating the sensorimotor 'flow' mode of creativity that bypasses higher-order cognition, but also indirectly through a systematic and conscious convergence on solutions, activating the 'deliberate' mode of creativity that relies on inhibition to reject common or task-inappropriate movement categories.

Influence of adiposity and physical activity on the cardiometabolic association pattern of lipoprotein subclasses to aerobic fitness in prepubertal children

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.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

Physical activity among children and adolescents is associated with lower adiposity, improved cardio-metabolic health, and improved fitness. Worldwide, fewer than 30% of children and adolescents meet global physical activity recommendations of at least 60 minutes of moderate to vigorous physical activity per day. Schools may be ideal sites for interventions given that children and adolescents in most parts of the world spend a substantial amount of time in transit to and from school or attending school.

OBJECTIVES

The purpose of this review update is to summarise the evidence on effectiveness of school-based interventions in increasing moderate to vigorous physical activity and improving fitness among children and adolescents 6 to 18 years of age. Specific objectives are: • to evaluate the effects of school-based interventions on increasing physical activity and improving fitness among children and adolescents; • to evaluate the effects of school-based interventions on improving body composition; and • to determine whether certain combinations or components (or both) of school-based interventions are more effective than others in promoting physical activity and fitness in this target population.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, BIOSIS, SPORTDiscus, and Sociological Abstracts to 1 June 2020, without language restrictions. We screened reference lists of included articles and relevant systematic reviews. We contacted primary authors of studies to ask for additional information.

SELECTION CRITERIA

Eligible interventions were relevant to public health practice (i.e. were not delivered by a clinician), were implemented in the school setting, and aimed to increase physical activity among all school-attending children and adolescents (aged 6 to 18) for at least 12 weeks. The review was limited to randomised controlled trials. For this update, we have added two new criteria: the primary aim of the study was to increase physical activity or fitness, and the study used an objective measure of physical activity or fitness. Primary outcomes included proportion of participants meeting physical activity guidelines and duration of moderate to vigorous physical activity and sedentary time (new to this update). Secondary outcomes included measured body mass index (BMI), physical fitness, health-related quality of life (new to this update), and adverse events (new to this update). Television viewing time, blood cholesterol, and blood pressure have been removed from this update.  DATA COLLECTION AND ANALYSIS: Two independent review authors used standardised forms to assess each study for relevance, to extract data, and to assess risk of bias. When discrepancies existed, discussion occurred until consensus was reached. Certainty of evidence was assessed according to GRADE. A random-effects meta-analysis based on the inverse variance method was conducted with participants stratified by age (children versus adolescents) when sufficient data were reported. Subgroup analyses explored effects by intervention type.

MAIN RESULTS

Based on the three new inclusion criteria, we excluded 16 of the 44 studies included in the previous version of this review. We screened an additional 9968 titles (search October 2011 to June 2020), of which 978 unique studies were potentially relevant and 61 met all criteria for this update. We included a total of 89 studies representing complete data for 66,752 study participants. Most studies included children only (n = 56), followed by adolescents only (n = 22), and both (n = 10); one study did not report student age. Multi-component interventions were most common (n = 40), followed by schooltime physical activity (n = 19), enhanced physical education (n = 15), and before and after school programmes (n = 14); one study explored both enhanced physical education and an after school programme. Lack of blinding of participants, personnel, and outcome assessors and loss to follow-up were the most common sources of bias.  Results show that school-based physical activity interventions probably result in little to no increase in time engaged in moderate to vigorous physical activity (mean difference (MD) 0.73 minutes/d, 95% confidence interval (CI) 0.16 to 1.30; 33 studies; moderate-certainty evidence) and may lead to little to no decrease in sedentary time (MD -3.78 minutes/d, 95% CI -7.80 to 0.24; 16 studies; low-certainty evidence). School-based physical activity interventions may improve physical fitness reported as maximal oxygen uptake (VO₂max) (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82; 13 studies; low-certainty evidence). School-based physical activity interventions may result in a very small decrease in BMI z-scores (MD -0.06, 95% CI -0.09 to -0.02; 21 studies; low-certainty evidence) and may not impact BMI expressed as kg/m² (MD -0.07, 95% CI -0.15 to 0.01; 50 studies; low-certainty evidence). We are very uncertain whether school-based physical activity interventions impact health-related quality of life or adverse events.

AUTHORS' CONCLUSIONS

Given the variability of results and the overall small effects, school staff and public health professionals must give the matter considerable thought before implementing school-based physical activity interventions. Given the heterogeneity of effects, the risk of bias, and findings that the magnitude of effect is generally small, results should be interpreted cautiously.

Cardiometabolic Associations between Physical Activity, Adiposity, and Lipoprotein Subclasses in Prepubertal Norwegian Children

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.

Bi-directional prospective associations between sedentary time, physical activity and adiposity in 10-year old Norwegian children

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.

Food environment intervention improves food knowledge, wellbeing and dietary habits in primary school children: Project Daire, a randomised-controlled, factorial design cluster trial

Background

Evidence suggests that dietary intake of UK children is suboptimal. As schools provide an ideal natural environment for public health interventions, effective and sustainable methods of improving food knowledge and dietary habits in this population must be identified. Project Daire aimed to improve children’s health-related quality of life, wellbeing, food knowledge and dietary habits via two multi-component interventions.

Methods

Daire was a randomised-controlled, factorial design trial evaluating two interventions across four arms. Primary schools in Northern Ireland were randomised to one of four 6-month intervention arms: i) ‘Nourish’, ii) ‘Engage’, iii) ‘Nourish’ and ‘Engage’ and iv) Control (Delayed). ‘Nourish’ was an intervention aiming to alter the whole-school food environment, provide food-related experiences and exposure to locally produced foods. ‘Engage’ was an age-appropriate, cross-curricular educational intervention on food, agriculture, nutrition science and related careers. Primary outcomes were emotional and behavioural wellbeing and health-related quality of life. A number of secondary outcomes, including dietary intake, cooking competence and food-related knowledge, were also measured.

Results

Fifteen schools from areas of varying socio-economic status participated in the randomised trial. A total of 903 (n = 445 aged 6–7 years and n = 458 aged 10–11 years) primary school pupils took part. Total Difficulties Score improved in all pupils (6–7 and 10–11 year old pupils) who received the ‘Nourish’ intervention compared with those that did not (adjusted difference in mean = − 0.82; 95% CI -1.46, − 0.17; P < 0.02). No statistically significant difference in Health-Related Quality of Life was observed. The ‘Nourish’ intervention also produced some changes in school-based dietary behaviour, which were most apparent in the 10–11 year old pupils. The ‘Nourish’ intervention also produced improvements in understanding of food labels (adjusted difference in mean = 0.15; 95% CI 0.05, 0.25; P < 0.01) and knowledge of vegetables in season (adjusted difference in mean = 0.29; 95% CI 0.01,0.56; P = 0.04) whilst an increased willingness to try new foods and improved perceived cooking competence was also observed.

Conclusions

Improvements in childhood emotional and behavioural wellbeing, dietary intake, knowledge about food, cooking skills and willingness to try new foods were associated with the ‘Nourish’ whole-school food environment intervention. Exploration of the sustainability and long-term effectiveness of such whole-school food interventions should be conducted.

Trial registration

National Institute of Health (NIH) U.S. National Library of Medicine Clinical Trials.gov (ID: NCT04277312).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01086-y.

Birth weight, cardiometabolic risk factors and effect modification of physical activity in children and adolescents: pooled data from 12 international studies

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.

Changes in Physical Activity, Physical Fitness and Well-Being Following a School-Based Health Promotion Program in a Norwegian Region with a Poor Public Health Profile: A Non-Randomized Controlled Study in Early Adolescents

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.

Effects of the Active Smarter Kids (ASK) physical activity intervention on cardiometabolic risk factors in children: A cluster-randomized controlled trial

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.

Implementing physically active learning: Future directions for research, policy, and practice

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).

Accelerometer epoch setting is decisive for associations between physical activity and metabolic health in children

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.

Multicollinear physical activity accelerometry data and associations to cardiometabolic health: challenges, pitfalls, and potential solutions

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.

Electronic supplementary material

The online version of this article (10.1186/s12966-019-0836-z) contains supplementary material, which is available to authorized users.

How Lifestyle Factors Affect Cognitive and Executive Function and the Ability to Learn in Children

In today's research environment, children's diet, physical activity, and other lifestyle factors are commonly studied in the context of health, independent of their effect on cognition and learning. Moreover, there is little overlap between the two literatures, although it is reasonable to expect that the lifestyle factors explored in the health-focused research are intertwined with cognition and learning processes. This thematic review provides an overview of knowledge connecting the selected lifestyle factors of diet, physical activity, and sleep hygiene to children's cognition and learning. Research from studies of diet and nutrition, physical activity and fitness, sleep, and broader influences of cultural and socioeconomic factors related to health and learning, were summarized to offer examples of research that integrate lifestyle factors and cognition with learning. The literature review demonstrates that the associations and causal relationships between these factors are vastly understudied. As a result, current knowledge on predictors of optimal cognition and learning is incomplete, and likely lacks understanding of many critical facts and relationships, their interactions, and the nature of their relationships, such as there being mediating or confounding factors that could provide important knowledge to increase the efficacy of learning-focused interventions. This review provides information focused on studies in children. Although basic research in cells or animal studies are available and indicate a number of possible physiological pathways, inclusion of those data would distract from the fact that there is a significant gap in knowledge on lifestyle factors and optimal learning in children. In a climate where childcare and school feeding policies are continuously discussed, this thematic review aims to provide an impulse for discussion and a call for more holistic approaches to support child development.

Cardiometabolic risk factor levels in Norwegian children compared to international reference values: The ASK study

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.

Interpretation of Multivariate Association Patterns between Multicollinear Physical Activity Accelerometry Data and Cardiometabolic Health in Children-A Tutorial

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.

Associations of physical activity and sedentary time with lipoprotein subclasses in Norwegian schoolchildren: The Active Smarter Kids (ASK) study

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.

The ActiGraph counts processing and the assessment of vigorous activity

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.

Physical activity preferences of 10-year-old children and identified activities with positive and negative associations to cardiorespiratory fitness

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.

Effects of a physical activity intervention on schoolchildren's health-related quality of life: The active smarter kids (ASK) cluster-randomized controlled trial

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.

Associations of volumes and patterns of physical activity with metabolic health in children: A multivariate pattern analysis approach

Physical activity (PA) favorably affects metabolic health in children, but it is unclear how total volumes versus patterns (bouts and breaks) of PA relate to health. By means of multivariate pattern analysis that can handle collinear variables, we determined the associations of PA volumes and patterns with children's metabolic health using different epoch settings. A sample of 841 Norwegian children (age 10.2 ± 0.3 years) provided in 2014 data on accelerometry (ActiGraph GT3X+), using epoch settings of 1, 10, and 60 s and several indices of metabolic health used to create a composite metabolic health score. We created 355 PA indices covering the whole intensity and bout duration spectrum, and used multivariate pattern analysis to analyze the data. Findings showed that bouts of PA added information about childhood health beyond total volumes of PA for all epoch settings. Yet, associations of PA patterns with metabolic health were completely dependent on the epoch settings used. Vigorous PA was strongly associated with metabolic health, while associations of light and moderate PA were weak to moderate, and associations of sedentary time with metabolic health was non-existing. Short intermittent bursts of PA were favorably associated with children's metabolic health, whereas associations of prolonged bouts were weak. This study is the first to determine the multivariate physical activity association pattern related to metabolic health in children across the whole PA intensity and bout duration spectrum. The findings challenge our understanding of PA patterns, and are of major importance for the analysis of accelerometry data.

The multivariate physical activity signature associated with metabolic health in children

Background

Physical activity is a cornerstone for promoting good metabolic health in children, but it is heavily debated which intensities (including sedentary time) are most influential. A fundamental limitation to current evidence for this relationship is the reliance on analytic approaches that cannot handle collinear variables. The aim of the present study was to determine the physical activity signature related to metabolic health in children, by investigating the association pattern for the whole spectrum of physical activity intensities using multivariate pattern analysis.

Methods

We used a sample of 841 children (age 10.2 ± 0.3 years; BMI 18.0 ± 3.0; 50% boys) from the Active Smarter Kids study, who provided 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 16 physical activity variables covering the whole intensity spectrum (from 0–100 to ≥ 8000 counts per minute) and used multivariate pattern analysis to analyze the data.

Results

Physical activity intensities in the vigorous range (5000–7000 counts per minute) were most strongly associated with metabolic health. Moderate intensity physical activity was weakly related to health, and sedentary time and light physical activity were not related to health.

Conclusions

This study is the first to determine the multivariate physical activity signature related to metabolic health in children across the whole intensity spectrum. This novel approach shows that vigorous physical activity is strongest related to metabolic health. We recommend future studies adapt a multivariate analytic approach to further develop the field of physical activity epidemiology.

Trial registration

The study was registered in Clinicaltrials.gov (www.clinicaltrials.gov) 7th of April 2014 with identification number NCT02132494.

Reproducibility of domain-specific physical activity over two seasons in children

BACKGROUND

Knowledge of the reproducibility of domain-specific accelerometer-determined physical activity (PA) estimates are a prerequisite to conduct high-quality epidemiological studies. The aim of this study was to determine the reproducibility of objectively measured PA level in children during school hours, afternoon hours, weekdays, weekend days, and total leisure time over two different seasons.

METHODS

Six hundred seventy six children from the Active Smarter Kids study conducted in Sogn og Fjordane, Norway, were monitored for 7 days by accelerometry (ActiGraph GT3X+) during January-February and April-May 2015. Reproducibility was estimated week-by-week using intra-class correlation (ICC) and Bland-Altman plots with 95% limits of agreement (LoA).

RESULTS

When controlling for season, reliability (ICC) was 0.51-0.66 for a 7-day week, 0.55-0.64 for weekdays, 0.11-0.43 for weekend days, 0.57-0.63 for school hours, 0.42-0.53 for afternoon hours, and 0.42-0.61 for total leisure time. LoA across models approximated a factor of 1.3-2.5 standard deviations of the sample PA levels. 3-6 weeks of monitoring were required to achieve a reliability of 0.80 across all domains but weekend days, which required 5-32 weeks.

CONCLUSION

Reproducibility of PA during leisure time and weekend days were lower than for school hours and weekdays, and estimates were lower when analyzed using a week-by-week approach over different seasons compared to previous studies relying on a single short monitoring period. To avoid type 2-errors, researchers should consider increasing the monitoring period beyond a single 7-day period in future studies.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT021324947 . Registered on 7 April 2014.

A comparison of 10 accelerometer non-wear time criteria and logbooks in children

BACKGROUND

There are many unresolved issues regarding data reduction algorithms for accelerometry. The choice of criterion for removal of non-wear time might have a profound influence on physical activity (PA) and sedentary time (SED) estimates. The aim of the present study was to compare 10 different non-wear criteria and a log of non-wear periods in 11-year-old children.

METHODS

Children from the Active Smarter Kids study performed 7-days of hip-worn accelerometer monitoring (Actigraph GT3X+) and logged the number of non-wear periods each day, along with the approximate duration and reason for non-wear. Accelerometers were analyzed using 10 different non-wear criteria: ≥ 10, 20, 30, 45, 60, and 90 min of consecutive zero counts without allowance for interruptions, and ≥60 and 90 min with allowance for 1 and 2 min of interruptions.

RESULTS

891 children provided 5203 measurement days, and reported 1232 non-wear periods ranging from 0 to 3 periods per day: on most days children reported no non-wear periods (77.1% of days). The maximum number of non-wear periods per day was 2 for the 90-min criterion, 3 to 5 for most criteria, 7 for the 20-min criterion, and 20 for the 10-min criterion. The non-wear criteria influenced overall PA (mean values across all criteria: 591 to 649 cpm; 10% difference) and SED time (461 to 539 min/day; 17% difference) estimates, especially for the most prolonged SED bouts. Estimates were similar for time spent in intensity-specific (light, moderate, vigorous, and moderate-to-vigorous) PA, but varied 6-9% among the non-wear criteria for proportions of time spent in intensity-specific PA (% of total wear time).

CONCLUSIONS

Population level estimates of PA and SED differed between different accelerometer non-wear criteria, meaning that non-wear time algorithms should be standardized across studies to reduce confusion and improve comparability of children's PA level. Based on the numbers and reasons for non-wear periods, we suggest a 45 or 60-min consecutive zero count-criterion not allowing any interruptions to be applied in future pediatric studies, at least for children older than 10 years.

TRIAL REGISTRATION

The study is registered in Clinicaltrials.gov with identification number NCT02132494 . Registered 7 April 2014.

Physical activity, diet and other behavioural interventions for improving cognition and school achievement in children and adolescents with obesity or overweight

BACKGROUND

The global prevalence of childhood and adolescent obesity is high. Lifestyle changes towards a healthy diet, increased physical activity and reduced sedentary activities are recommended to prevent and treat obesity. Evidence suggests that changing these health behaviours can benefit cognitive function and school achievement in children and adolescents in general. There are various theoretical mechanisms that suggest that children and adolescents with excessive body fat may benefit particularly from these interventions.

OBJECTIVES

To assess whether lifestyle interventions (in the areas of diet, physical activity, sedentary behaviour and behavioural therapy) improve school achievement, cognitive function (e.g. executive functions) and/or future success in children and adolescents with obesity or overweight, compared with standard care, waiting-list control, no treatment, or an attention placebo control group.

SEARCH METHODS

In February 2017, we searched CENTRAL, MEDLINE and 15 other databases. We also searched two trials registries, reference lists, and handsearched one journal from inception. We also contacted researchers in the field to obtain unpublished data.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials (RCTs) of behavioural interventions for weight management in children and adolescents with obesity or overweight. We excluded studies in children and adolescents with medical conditions known to affect weight status, school achievement and cognitive function. We also excluded self- and parent-reported outcomes.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected studies for inclusion. Two review authors extracted data, assessed quality and risks of bias, and evaluated the quality of the evidence using the GRADE approach. We contacted study authors to obtain additional information. We used standard methodological procedures expected by Cochrane. Where the same outcome was assessed across different intervention types, we reported standardised effect sizes for findings from single-study and multiple-study analyses to allow comparison of intervention effects across intervention types. To ease interpretation of the effect size, we also reported the mean difference of effect sizes for single-study outcomes.

MAIN RESULTS

We included 18 studies (59 records) of 2384 children and adolescents with obesity or overweight. Eight studies delivered physical activity interventions, seven studies combined physical activity programmes with healthy lifestyle education, and three studies delivered dietary interventions. We included five RCTs and 13 cluster-RCTs. The studies took place in 10 different countries. Two were carried out in children attending preschool, 11 were conducted in primary/elementary school-aged children, four studies were aimed at adolescents attending secondary/high school and one study included primary/elementary and secondary/high school-aged children. The number of studies included for each outcome was low, with up to only three studies per outcome. The quality of evidence ranged from high to very low and 17 studies had a high risk of bias for at least one item. None of the studies reported data on additional educational support needs and adverse events.Compared to standard practice, analyses of physical activity-only interventions suggested high-quality evidence for improved mean cognitive executive function scores. The mean difference (MD) was 5.00 scale points higher in an after-school exercise group compared to standard practice (95% confidence interval (CI) 0.68 to 9.32; scale mean 100, standard deviation 15; 116 children, 1 study). There was no statistically significant beneficial effect in favour of the intervention for mathematics, reading, or inhibition control. The standardised mean difference (SMD) for mathematics was 0.49 (95% CI -0.04 to 1.01; 2 studies, 255 children, moderate-quality evidence) and for reading was 0.10 (95% CI -0.30 to 0.49; 2 studies, 308 children, moderate-quality evidence). The MD for inhibition control was -1.55 scale points (95% CI -5.85 to 2.75; scale range 0 to 100; SMD -0.15, 95% CI -0.58 to 0.28; 1 study, 84 children, very low-quality evidence). No data were available for average achievement across subjects taught at school.There was no evidence of a beneficial effect of physical activity interventions combined with healthy lifestyle education on average achievement across subjects taught at school, mathematics achievement, reading achievement or inhibition control. The MD for average achievement across subjects taught at school was 6.37 points lower in the intervention group compared to standard practice (95% CI -36.83 to 24.09; scale mean 500, scale SD 70; SMD -0.18, 95% CI -0.93 to 0.58; 1 study, 31 children, low-quality evidence). The effect estimate for mathematics achievement was SMD 0.02 (95% CI -0.19 to 0.22; 3 studies, 384 children, very low-quality evidence), for reading achievement SMD 0.00 (95% CI -0.24 to 0.24; 2 studies, 284 children, low-quality evidence), and for inhibition control SMD -0.67 (95% CI -1.50 to 0.16; 2 studies, 110 children, very low-quality evidence). No data were available for the effect of combined physical activity and healthy lifestyle education on cognitive executive functions.There was a moderate difference in the average achievement across subjects taught at school favouring interventions targeting the improvement of the school food environment compared to standard practice in adolescents with obesity (SMD 0.46, 95% CI 0.25 to 0.66; 2 studies, 382 adolescents, low-quality evidence), but not with overweight. Replacing packed school lunch with a nutrient-rich diet in addition to nutrition education did not improve mathematics (MD -2.18, 95% CI -5.83 to 1.47; scale range 0 to 69; SMD -0.26, 95% CI -0.72 to 0.20; 1 study, 76 children, low-quality evidence) and reading achievement (MD 1.17, 95% CI -4.40 to 6.73; scale range 0 to 108; SMD 0.13, 95% CI -0.35 to 0.61; 1 study, 67 children, low-quality evidence).

AUTHORS' CONCLUSIONS

Despite the large number of childhood and adolescent obesity treatment trials, we were only able to partially assess the impact of obesity treatment interventions on school achievement and cognitive abilities. School and community-based physical activity interventions as part of an obesity prevention or treatment programme can benefit executive functions of children with obesity or overweight specifically. Similarly, school-based dietary interventions may benefit general school achievement in children with obesity. These findings might assist health and education practitioners to make decisions related to promoting physical activity and healthy eating in schools. Future obesity treatment and prevention studies in clinical, school and community settings should consider assessing academic and cognitive as well as physical outcomes.

Regular Physical Activity and Educational Outcomes in Youth: A Longitudinal Study

PURPOSE

The objectives of this study were to determine whether longitudinal changes in accelerometer-assessed moderate-to-vigorous physical activity (MVPA) were associated with changes in educational outcomes (i.e., academic performance and mathematics engagement) and to examine whether the association was nonlinear.

METHODS

Longitudinal data were collected from 2,194 Australian adolescents (mean age = 13.40 years, standard deviation = .73) at two time points (Term 1, 2014, and Term 2, 2015). To measure the total MVPA, the adolescents wore an accelerometer for seven consecutive days. The participants responded to a questionnaire to measure mathematics engagement and completed a nationally administered numeracy test to assess academic performance.

RESULTS

Latent change score models indicated that increases in MVPA had a positive quadratic association with National Assessment Program-Literacy and Numeracy (NAPLAN) scores in girls (β = .39, p < .001) but not boys. In comparison, cross-sectional regression analyses indicated that MVPA had a positive quadratic association with NAPLAN scores in grade 7 (β = .92, p = .04) boys and in grade 9 boys (β = .60, p = .06), but not in girls. There was also a positive quadratic association between MVPA and school engagement in grade 9 boys (β = .77, p = .03).

CONCLUSIONS

Cross-sectional evidence indicated that boys who were more physically active had better educational outcomes than their less active peers, and girls who increased their regular physical activity showed improvements in academic performance. All students need to increase their physical activity levels for health and educational benefits, without compromising the time spent on study and homework.

Executive Function, Behavioral Self-Regulation, and School Related Well-Being Did Not Mediate the Effect of School-Based Physical Activity on Academic Performance in Numeracy in 10-Year-Old Children. The Active Smarter Kids (ASK) Study

Inconsistent findings exist for the effect of school-based physical activity interventions on academic performance. The Active Smarter Kids (ASK) study revealed a favorable intervention effect of school-based physical activity on academic performance in numeracy in a subsample of 10-year-old elementary schoolchildren performing poorer at baseline in numeracy. Aiming to explain this finding, we investigated the mediating effects of executive function, behavioral self-regulation, and school related well-being in the relation between the physical activity intervention and child's performance in numeracy. An ANCOVA model with latent variable structural equation modeling was estimated using data from 360 children (the lower third in academic performance in numeracy at baseline). The model consisted of the three latent factors as mediators; executive function, behavioral self-regulation, and school related well-being. We found no mediating effects of executive function, behavioral self-regulation or school related well-being in the relationship between the ASK intervention and academic performance in numeracy (p ≥ 0.256). Our results suggest that the effect of the intervention on performance in numeracy in the present sample is not explained by change in executive function, behavioral self-regulation, or school related well-being. We suggest this finding mainly could be explained by the lack of effect of the intervention on the mediators, which might be due to an insufficient dose of physical activity. Trial registration: Clinicaltrials.gov registry, trial registration number: NCT02132494.

Physical activity, diet and other behavioural interventions for improving cognition and school achievement in children and adolescents with obesity or overweight

BACKGROUND

The global prevalence of childhood and adolescent obesity is high. Lifestyle changes towards a healthy diet, increased physical activity and reduced sedentary activities are recommended to prevent and treat obesity. Evidence suggests that changing these health behaviours can benefit cognitive function and school achievement in children and adolescents in general. There are various theoretical mechanisms that suggest that children and adolescents with excessive body fat may benefit particularly from these interventions.

OBJECTIVES

To assess whether lifestyle interventions (in the areas of diet, physical activity, sedentary behaviour and behavioural therapy) improve school achievement, cognitive function (e.g. executive functions) and/or future success in children and adolescents with obesity or overweight, compared with standard care, waiting-list control, no treatment, or an attention placebo control group.

SEARCH METHODS

In February 2017, we searched CENTRAL, MEDLINE and 15 other databases. We also searched two trials registries, reference lists, and handsearched one journal from inception. We also contacted researchers in the field to obtain unpublished data.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials (RCTs) of behavioural interventions for weight management in children and adolescents with obesity or overweight. We excluded studies in children and adolescents with medical conditions known to affect weight status, school achievement and cognitive function. We also excluded self- and parent-reported outcomes.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected studies for inclusion. Two review authors extracted data, assessed quality and risks of bias, and evaluated the quality of the evidence using the GRADE approach. We contacted study authors to obtain additional information. We used standard methodological procedures expected by Cochrane. Where the same outcome was assessed across different intervention types, we reported standardised effect sizes for findings from single-study and multiple-study analyses to allow comparison of intervention effects across intervention types. To ease interpretation of the effect size, we also reported the mean difference of effect sizes for single-study outcomes.

MAIN RESULTS

We included 18 studies (59 records) of 2384 children and adolescents with obesity or overweight. Eight studies delivered physical activity interventions, seven studies combined physical activity programmes with healthy lifestyle education, and three studies delivered dietary interventions. We included five RCTs and 13 cluster-RCTs. The studies took place in 10 different countries. Two were carried out in children attending preschool, 11 were conducted in primary/elementary school-aged children, four studies were aimed at adolescents attending secondary/high school and one study included primary/elementary and secondary/high school-aged children. The number of studies included for each outcome was low, with up to only three studies per outcome. The quality of evidence ranged from high to very low and 17 studies had a high risk of bias for at least one item. None of the studies reported data on additional educational support needs and adverse events.Compared to standard practice, analyses of physical activity-only interventions suggested high-quality evidence for improved mean cognitive executive function scores. The mean difference (MD) was 5.00 scale points higher in an after-school exercise group compared to standard practice (95% confidence interval (CI) 0.68 to 9.32; scale mean 100, standard deviation 15; 116 children, 1 study). There was no statistically significant beneficial effect in favour of the intervention for mathematics, reading, or inhibition control. The standardised mean difference (SMD) for mathematics was 0.49 (95% CI -0.04 to 1.01; 2 studies, 255 children, moderate-quality evidence) and for reading was 0.10 (95% CI -0.30 to 0.49; 2 studies, 308 children, moderate-quality evidence). The MD for inhibition control was -1.55 scale points (95% CI -5.85 to 2.75; scale range 0 to 100; SMD -0.15, 95% CI -0.58 to 0.28; 1 study, 84 children, very low-quality evidence). No data were available for average achievement across subjects taught at school.There was no evidence of a beneficial effect of physical activity interventions combined with healthy lifestyle education on average achievement across subjects taught at school, mathematics achievement, reading achievement or inhibition control. The MD for average achievement across subjects taught at school was 6.37 points lower in the intervention group compared to standard practice (95% CI -36.83 to 24.09; scale mean 500, scale SD 70; SMD -0.18, 95% CI -0.93 to 0.58; 1 study, 31 children, low-quality evidence). The effect estimate for mathematics achievement was SMD 0.02 (95% CI -0.19 to 0.22; 3 studies, 384 children, very low-quality evidence), for reading achievement SMD 0.00 (95% CI -0.24 to 0.24; 2 studies, 284 children, low-quality evidence), and for inhibition control SMD -0.67 (95% CI -1.50 to 0.16; 2 studies, 110 children, very low-quality evidence). No data were available for the effect of combined physical activity and healthy lifestyle education on cognitive executive functions.There was a moderate difference in the average achievement across subjects taught at school favouring interventions targeting the improvement of the school food environment compared to standard practice in adolescents with obesity (SMD 0.46, 95% CI 0.25 to 0.66; 2 studies, 382 adolescents, low-quality evidence), but not with overweight. Replacing packed school lunch with a nutrient-rich diet in addition to nutrition education did not improve mathematics (MD -2.18, 95% CI -5.83 to 1.47; scale range 0 to 69; SMD -0.26, 95% CI -0.72 to 0.20; 1 study, 76 children, low-quality evidence) and reading achievement (MD 1.17, 95% CI -4.40 to 6.73; scale range 0 to 108; SMD 0.13, 95% CI -0.35 to 0.61; 1 study, 67 children, low-quality evidence).

AUTHORS' CONCLUSIONS

Despite the large number of childhood and adolescent obesity treatment trials, we were only able to partially assess the impact of obesity treatment interventions on school achievement and cognitive abilities. School and community-based physical activity interventions as part of an obesity prevention or treatment programme can benefit executive functions of children with obesity or overweight specifically. Similarly, school-based dietary interventions may benefit general school achievement in children with obesity. These findings might assist health and education practitioners to make decisions related to promoting physical activity and healthy eating in schools. Future obesity treatment and prevention studies in clinical, school and community settings should consider assessing academic and cognitive as well as physical outcomes.

Gender-specific effects of physical activity on children's academic performance: The Active Smarter Kids cluster randomized controlled trial

Active learning combines academic content with physical activity (PA) to increase child PA and academic performance, but the impact of active learning is mixed. It may be that this is a moderated relationship in which active learning is beneficial for only some children. This paper examine the impact of baseline academic performance and gender as moderators for the effects of active learning on children's academic performance. In the ASK-study, 1129 fifth-graders from 57 Norwegian elementary schools were randomized by school to intervention or control in a physical activity intervention between November 2014 and June 2015. Academic performance in numeracy, reading, and English was measured and a composite score was calculated. Children were split into low, middle and high academic performing tertiles. 3-way-interactions for group (intervention, control)∗gender (boys, girls)∗academic performance (tertiles) were investigated using mixed model regression. There was a significant, 3-way-interaction (p=0.044). Both boys (ES=0.11) and girls (ES=0.18) in the low performing tertile had a similar beneficial trend. In contrast, middle (ES=0.03) and high performing boys (ES=0.09) responded with small beneficial trends, while middle (ES=-0.11) and high performing girls (ES=-0.06) responded with negative trends. ASK was associated with a significant increase in academic performance for low performing children. It is likely that active learning benefited children most in need of adapted education but it may have a null or negative effect for those girls who are already performing well in the sedentary classroom. Differences in gendered responses are discussed as a possible explanation for these results.

TRIAL REGISTRATION

Clinicaltrials.gov registry, trial registration number: NCT02132494.

Reproducibility of objectively measured physical activity and sedentary time over two seasons in children; Comparing a day-by-day and a week-by-week approach

Introduction

Knowledge of reproducibility of accelerometer-determined physical activity (PA) and sedentary time (SED) estimates are a prerequisite to conduct high-quality epidemiological studies. Yet, estimates of reproducibility might differ depending on the approach used to analyze the data. The aim of the present study was to determine the reproducibility of objectively measured PA and SED in children by directly comparing a day-by-day and a week-by-week approach to data collected over two weeks during two different seasons 3–4 months apart.

Methods

676 11-year-old children from the Active Smarter Kids study conducted in Sogn og Fjordane county, Norway, performed 7 days of accelerometer monitoring (ActiGraph GT3X+) during January-February and April-May 2015. Reproducibility was calculated using a day-by-day and a week-by-week approach applying mixed effect modelling and the Spearman Brown prophecy formula, and reported using intra-class correlation (ICC), Bland Altman plots and 95% limits of agreement (LoA).

Results

Applying a week-by-week approach, no variables provided ICC estimates ≥ 0.70 for one week of measurement in any model (ICC = 0.29–0.66 not controlling for season; ICC = 0.49–0.67 when controlling for season). LoA for these models approximated a factor of 1.3–1.7 of the sample PA level standard deviations. Compared to the week-by-week approach, the day-by-day approach resulted in too optimistic reliability estimates (ICC = 0.62–0.77 not controlling for season; ICC = 0.64–0.77 when controlling for season).

Conclusions

Reliability is lower when analyzed over different seasons and when using a week-by-week approach, than when applying a day-by-day approach and the Spearman Brown prophecy formula to estimate reliability over a short monitoring period. We suggest a day-by-day approach and the Spearman Brown prophecy formula to determine reliability be used with caution.

Trial Registration

The study is registered in Clinicaltrials.gov 7^th April 2014 with identification number NCT02132494.

Children`s lifestyle behaviors in relation to anthropometric indices: a family practice study

Introduction

Obesity prevention in children represents one of the main concerns in primary care. In order to develop into a healthy adult, the child has to follow a healthy lifestyle in all aspects: nutritional, behavioral, physical and recreational. Our main goal was to identify which habits may influence the children’s somatic development.

Method

Our study, performed in a family practice, consisted in a questionnaire regarding physical activity, diet and use of electronic devices.

After obtaining the parent’s and child’s informed consent to participate in our cross-sectional study, 98 consecutive children aged 5–15 years, examined in the family practice, were enlisted. After collecting the answers, weight, height, waist circumference, wrist circumference, subscapular skinfold thickness were measured and body mass index was calculated.

Results

The analysis of the relationship between the anthropometric data showed a significant difference between girls and boys only in respect of the wrist circumference. The groups performing daily household activities had a significantly increased weight, BMI, abdominal and wrist circumference. Participation in physical education classes in school was associated significantly only with the wrist circumference. Frequent change of the option for extracurricular sport showed a significant difference in weight, waist circumference, and wrist in favor of the group that practiced many sports. Fast food diet and the type of alimentary habits of the family (home cooked, pre-cooked, or ordered food) showed differences between medians of the anthropometric indices with higher values for those eating more frequently fast food or ordered food, yet without reaching statistical significance.

Conclusion

Both girls and boys, in the presence of an unhealthy lifestyle (lack of recreational and educational physical activity, food habits, inappropriate time spent in front of a screen) had unfavorable adiposity indices.

Executive Functions Do Not Mediate Prospective Relations between Indices of Physical Activity and Academic Performance: The Active Smarter Kids (ASK) Study

Changes in cognitive function induced by physical activity have been proposed as a mechanism for the link between physical activity and academic performance. The aim of this study was to investigate if executive function mediated the prospective relations between indices of physical activity and academic performance in a sample of 10-year-old Norwegian children. The study included 1,129 children participating in the Active Smarter Kids (ASK) trial, followed over 7 months. Structural equation modeling (SEM) with a latent variable of executive function (measuring inhibition, working memory, and cognitive flexibility) was used in the analyses. Predictors were objectively measured physical activity, time spent sedentary, aerobic fitness, and motor skills. Outcomes were performance on national tests of numeracy, reading, and English (as a second language). Generally, indices of physical activity did not predict executive function and academic performance. A modest mediation effect of executive function was observed for the relation between motor skills and academic performance. Trial registration: Clinicaltrials.gov registry, trial registration number: NCT02132494.

Moderate-to-vigorous physical activity, but not sedentary time, predicts changes in cardiometabolic risk factors in 10-y-old children: the Active Smarter Kids Study

Background: Cross-sectional data have suggested an inverse relation between physical activity and cardiometabolic risk factors that is independent of sedentary time. However, little is known about which subcomponent of physical activity may predict cardiometabolic risk factors in youths.Objective: We examined the independent prospective associations between objectively measured sedentary time and subcomponents of physical activity with individual and clustered cardiometabolic risk factors in healthy children aged 10 y.Design: We included 700 children (49.1% males; 50.9% females) in which sedentary time and physical activity were measured with the use of accelerometry. Systolic blood pressure, waist circumference (WC), and fasting blood sample (total cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, fasting insulin) were measured with the use of standard clinical methods and analyzed individually and as a clustered cardiometabolic risk score standardized by age and sex (z score). Exposure and outcome variables were measured at baseline and at follow-up 7 mo later.Results: Sedentary time was not associated with any of the individual cardiometabolic risk factors or clustered cardiometabolic risk in prospective analyses. Moderate physical activity at baseline predicted lower concentrations of triglycerides (P = 0.021) and homeostatic model assessment for insulin resistance (P = 0.027) at follow-up independent of sex, socioeconomic status, Tanner stage, monitor wear time, or WC. Moderate-to-vigorous physical activity (P = 0.043) and vigorous physical activity (P = 0.028) predicted clustered cardiometabolic risk at follow-up, but these associations were attenuated after adjusting for WC.Conclusions: Physical activity, but not sedentary time, is prospectively associated with cardiometabolic risk in healthy children. Public health strategies aimed at improving children's cardiometabolic profile should strive for increasing physical activity of at least moderate intensity rather than reducing sedentary time. This trial was registered at clinicaltrials.gov as NCT02132494.