The Longitudinal Association of Cardiorespiratory Fitness and Adiposity With Clustered Cardiometabolic Risk: A Mediation Analysis.

PURPOSE: Previous literature has demonstrated the mediating role of adiposity in the association between cardiorespiratory fitness (CRF) and cardiometabolic risk as well as the potential role of CRF in attenuating the adverse consequences associated with excess weight. This study aimed to evaluate the mediating role of CRF and adiposity in the possible association with cardiometabolic risk. METHOD: Observational 3-year longitudinal study that included 420 children and adolescents (10.50 [2.05] y of age at baseline; 56.2% girls). Body mass index (BMI) was calculated, and CRF was evaluated using field assessments. A clustered cardiometabolic risk score (cMetS) was calculated from glucose, systolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, and triglycerides z scores. Analyses evaluated the mediating role of BMI in the association between CRF and cMetS as well as whether CRF mediated the association between BMI and cMetS. RESULTS: BMI at baseline was directly associated with the cMetS at follow-up (0.102; 95% confidence interval, 0.020 to 0.181), independently of CRF, whereas CRF was only indirectly associated with cMetS at follow-up through BMI (-0.036; 95% confidence interval, -0.070 to -0.009), meaning that the association between CRF and cMetS was explained via the mediation role of BMI. CONCLUSIONS: BMI presented direct association with cMetS, whereas CRF exhibited indirect association with cMetS mediated via BMI.

Gender differences in the distribution of children's physical activity: evidence from nine countries.

BACKGROUND: Physical activity in childhood is thought to influences health and development. Previous studies have found that boys are typically more active than girls, yet the focus has largely been on differences in average levels or proportions above a threshold rather than the full distribution of activity across all intensities. We thus examined differences in the distribution of physical activity between girls and boys in a multi-national sample of children. METHODS: We used the harmonised International Children Accelerometry Database (ICAD), including waist-worn accelerometry data from 15,461 individuals (Boys: 48.3%) from 9 countries. Employing Generalised Additive Models of Location, Shape, and Scale (GAMLSS) we investigated gender differences in the distribution of individuals, including comparisons of variability (SD) and average physical activity levels (mean and median) and skewness. We conducted this analysis for each activity intensity (Sedentary, Light, and Moderate-to-Vigorous (MVPA)) and a summary measure (counts per minute (CPM)). RESULTS: Sizable gender differences in the distribution of activity were found for moderate to vigorous activity and counts per minute, with boys having higher average levels (38% higher mean volumes of MVPA, 20% higher CPM), yet substantially more between-person variability (30% higher standard deviation (SD) for MVPA, 17% higher SD for CPM); boys' distributions were less positively skewed than girls. Conversely, there was little to no difference between girls and boys in the distribution of sedentary or light-intensity activity. CONCLUSIONS: Inequality in activity between girls and boys was driven by MVPA. The higher mean volumes of MVPA in boys occurred alongside greater variability. This suggests a need to consider the underlying distribution of activity in future research; for example, interventions which target gender inequality in MVPA may inadvertently lead to increased inequality within girls.

What is the role of cardiorespiratory fitness and sedentary behavior in relationship between the genetic predisposition to obesity and cardiometabolic risk score?

BACKGROUND: Genetic factors along with inadequate lifestyle habits are associated with the development of cardiometabolic alterations. Thus, the present study aimed to examine the role of sedentary behavior on the relationship between rs9939609 polymorphism (fat mass and obesity-associated gene-FTO) and cardiometabolic risk score according to cardiorespiratory fitness (CRF) levels in children and adolescents. METHODS: A cross-sectional study with 1215 children and adolescents (692 girls), aged between 6 and 17 years. Screen time as a marker of sedentary behavior was evaluated through a self-reported questionnaire and CRF was estimated using the 6-min walking and running test. The genotyping of the FTO rs9939609 polymorphism was performed using a real-time polymerase chain reaction. Clustered cardiometabolic risk score (cMetS) was calculated by summing z-scores of total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, glucose, systolic blood pressure, and waist circumference, and dividing it by five. Moderation analyses were tested using multiple linear regression models. RESULTS: The coefficient of the interaction term of FTO (rs9939609) and screen time indicated that screen time was a significant moderator on the relationship between FTO rs9939609 polymorphism and cMetS (p = 0.047) in children and adolescents classified with low CRF (ß = 0.001; 95% CI = 0.001; 0.002). It was observed a significant association between genotype risk (AA) of FTO polymorphism and cMetS, in participants that spent more than 378 min a day in front of screen-based devices (ß = 0.203; 95% CI = 0.000; 0.405). No interaction term was found for those with high CRF. CONCLUSIONS: High sedentary behavior seems to influence the relationship between genetic predisposition to obesity and cardiometabolic risk factors in children and adolescents with low CRF.

GRANADA consensus on analytical approaches to assess associations with accelerometer-determined physical behaviours (physical activity, sedentary behaviour and sleep) in epidemiological studies.

The inter-relationship between physical activity, sedentary behaviour and sleep (collectively defined as physical behaviours) is of interest to researchers from different fields. Each of these physical behaviours has been investigated in epidemiological studies, yet their codependency and interactions need to be further explored and accounted for in data analysis. Modern accelerometers capture continuous movement through the day, which presents the challenge of how to best use the richness of these data. In recent years, analytical approaches first applied in other scientific fields have been applied to physical behaviour epidemiology (eg, isotemporal substitution models, compositional data analysis, multivariate pattern analysis, functional data analysis and machine learning). A comprehensive description, discussion, and consensus on the strengths and limitations of these analytical approaches will help researchers decide which approach to use in different situations. In this context, a scientific workshop and meeting were held in Granada to discuss: (1) analytical approaches currently used in the scientific literature on physical behaviour, highlighting strengths and limitations, providing practical recommendations on their use and including a decision tree for assisting researchers' decision-making; and (2) current gaps and future research directions around the analysis and use of accelerometer data. Advances in analytical approaches to accelerometer-determined physical behaviours in epidemiological studies are expected to influence the interpretation of current and future evidence, and ultimately impact on future physical behaviour guidelines.

Temporal trends in physical activity levels across more than a decade - a national physical activity surveillance system among Norwegian children and adolescents.

BACKGROUND: There is a scarcity of device measured data on temporal changes in physical activity (PA) in large population-based samples. The purpose of this study is to describe gender and age-group specific temporal trends in device measured PA between 2005, 2011 and 2018 by comparing three nationally representative samples of children and adolescents. METHODS: Norwegian children and adolescents (6, 9 and 15-year-olds) were invited to participate in 2005 (only 9- and 15-year-olds), 2011 and 2018 through cluster sampling (schools primary sampling units). A combined sample of 9500 individuals participated. Physical activity was assessed by hip worn accelerometers, with PA indices including overall PA (counts per minute), moderate-to-vigorous intensity PA (MVPA), and PA guideline adherence (achieving on average ≥ 60 min/day of moderate-to-vigorous PA). Random-effects linear regressions and logistic regressions adjusted for school-level clusters were used to analyse temporal trends. FINDINGS: In total, 8186 of the participating children and adolescents provided valid PA data. Proportions of sufficiently active 6-year-olds were almost identical in 2011 and 2018; boys 95% (95% CI: 92, 97) and 94% (95%CI: 92, 96) and girls 86% (95% CI: 83, 90) and 86% (95% CI: 82, 90). Proportions of sufficiently active 15-year-olds in 2005 and 2018 were 52% (95% CI: 46, 59) and 55% (95% CI: 48, 62) in boys, and 48% (95% CI: 42, 55) and 44% (95% CI: 37, 51) in girls, respectively, resulting from small differences in min/day of MVPA. Among 9-year-old boys and girls, proportions of sufficiently active declined between 2005 and 2018, from 90% (95% CI: 87, 93) to 84% (95% CI: 80, 87)) and 74% (95% CI: 69, 79) to 68% (95% CI: 64, 72), respectively. This resulted from 9.7 min/day less MVPA in boys (95% CI: - 14.8, - 4.7; p < 0.001) and 3.2 min/day less MVPA (95% CI: - 7.0, 0.7; p = 0.106) in girls. CONCLUSIONS: PA levels have been fairly stable between 2005, 2011 and 2018 in Norwegian youth. However, the declining PA level among 9-year-old boys and the low proportion of 15-year-olds sufficiently active is concerning. To evaluate the effect of, and plan for new, PA promoting strategies, it is important to ensure more frequent, systematic, device-based monitoring of population-levels of PA.

Association of change in the school travel mode with changes in different physical activity intensities and sedentary time: A International Children's Accelerometry Database Study.

Our aim was to assess the association between changes in active travel to school and changes in different intensities of physical activity (i.e. moderate - MPA and vigorous - VPA) and time spent sedentary (SED) among adolescents and assess the moderating effect of children's sex, age and weight status. Data from six cohort studies in the International Children's Accelerometry Database were used (4108 adolescents aged 10-13y at baseline, with 1.9±0.7y of follow-up). Participants self-reported travel mode to school at baseline and follow-up. Mutually exclusive categories of change were created using passive (e.g. by car) or active (cycling or walking) forms of transport (active/active, passive/active, active/passive, passive/passive). Multilevel linear regression analyses assessed associations with change in accelerometer-assessed time spent MPA, VPA and SED, adjusting for potential confounders. The moderation of sex, age and weight status was tested though the inclusion of interaction terms in the regression models. Relative to those remaining in active travel (active/active), participants classified as passive/active increased VPA (B: 2.23 min/d; 95%CI: 0.97-3.48), while active/passive (MPA: -5.38min/d; -6.77 to -3.98; VPA: -2.92min/d; -4.06 to -1.78) and passive/passive (MPA: -4.53min/d; -5.55 to -3.50; VPA: -2.84min/d; -3.68 to -2.01) decreased MPA and VPA. There were no associations with SED. An interaction was observed, age group moderated the association with change in VPA: among 12-13y-olds a greater increase in VPA was observed for the passive/active group compared to active/active. Promoting active travel to school can be a strategy to attenuate the decline in physical activity through adolescence.

Physical activity spectrum discriminant analysis-A method to compare detailed patterns between groups.

Investigating physical activity (PA) patterns as a detailed intensity spectrum instead of crude intensity categories have improved the ability to analyze the relationship between measured PA and health variables. The aim of this methodological study was to introduce and investigate the utility of using detailed PA intensity spectrum compared to crude PA intensity categories for comparison of PA between groups and between repeated measures. The study sample consisted of two groups of children, where one group was scheduled for extended physical education (PE) by daily classes while the other group followed usual PE schedule. Accelerometer data was processed into traditional crude PA intensity categories and into detailed PA intensity spectrum. Multivariate partial least squares regression for discriminant analysis (PLS-DA) was applied for PA intensity spectrum group comparison and compared to traditional univariate statistical analysis. Repeated measures were investigated using independent PLS-DA as well as multilevel PLS-DA for paired analysis. While traditional analysis of crude PA intensity categories was unable to find any group differences, multivariate analysis of the PA intensity spectrum identified statistically significant differences. By the extension of multilevel PLS-DA for paired comparison, a clear difference in the PA intensity spectrum was demonstrated between repeated measures. In conclusion, analysis of detailed PA intensity spectrum demonstrates utility for comparing detailed PA data between groups and between repeated measures in interventional and observational research.

Aerobic performance among healthy (non-asthmatic) adults using beta2-agonists: a systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: To examine the effect of beta2-agonists on aerobic performance in healthy, non-asthmatic study participants. DESIGN: Systematic review and meta-analysis. ELIGIBILITY CRITERIA: We searched four databases (PubMed, Embase, SPORTDiscus and Web of Science) for randomised controlled trials published until December 2019. Studies examining the effect of beta2-agonists on maximal physical performance lasting longer than 1 min were included in the meta-analysis. Data are presented as standardised difference in mean (SDM) with 95% CI. RESULTS: The present meta-analysis includes 47 studies. The studies comprise 607 participants in cross-over trials, including 99 participants in three-way cross-over trials and 27 participants in a four-way cross-over trial. Seventy-three participants were included in parallel trials. Beta2-agonists did not affect aerobic performance compared with placebo (SDM 0.051, 95% CI -0.020 to 0.122). The SDM for the included studies was not heterogeneous (I2=0%, p=0.893), and the effect was not related to type of beta2-agonist, dose, administration route, duration of treatment or performance level of participants. Beta2-agonists had no effect on time trial performance, time to exhaustion or maximal oxygen consumption (p<0.218). CONCLUSION/IMPLICATION: The present study shows that beta2-agonists do not affect aerobic performance in non-asthmatic subjects regardless of type, dose, administration route, duration of treatment or performance level of participants. The results of the present study should be of interest to WADA and to anyone who is interested in equal opportunities in competitive sports. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018109223.

A comparison of analytical approaches to investigate associations for accelerometry-derived physical activity spectra with health and developmental outcomes in children.

The use of high-resolution physical activity intensity spectra obtained from accelerometry can improve knowledge of associations with health and development beyond the use of traditional summary measures of intensity. The aim of the present study was to compare three different approaches for determining associations for spectrum descriptors of physical activity (the intensity gradient, principal component analysis, and multivariate pattern analysis) with relevant outcomes in children. We used two datasets including physical activity spectrum data (ActiGraph GT3X+) and 1) a cardiometabolic health outcome in 841 schoolchildren and 2) a motor skill outcome in 1081 preschool children. We compared variance explained (R2) and associations with the outcomes for the intensity gradient (slope) across the physical activity spectra, a two-component principal component model describing the physical activity variables, and multivariate pattern analysis using the intensity spectra as the explanatory data matrices. Results were broadly similar for all analytical approaches. Multivariate pattern analysis explained the most variance in both datasets, likely resulting from use of more of the information available from the intensity spectra. Yet, volume and intensity dimensions of physical activity are not easily disentangled and their relative importance may be interpreted differently using different methodology.

Effects of a physical activity program from diagnosis on cardiorespiratory fitness in children with cancer: a national non-randomized controlled trial.

BACKGROUND: Children with cancer experience impaired cardiorespiratory fitness and physical function during and after treatment restricting their possibilities to engage in social activities including sport, leisure activities, and school. The objectives were to determine the effects of classmate-supported, controlled, supervised, in-hospital, physical activity program to preserve cardiorespiratory fitness and physical function from time of diagnosis in children with cancer. METHODS: National non-randomized controlled trial including schoolchildren aged 6-18 years at diagnosis treated with chemo-/radiotherapy. We included 120 of 128 eligible patients (94%) in the intervention group (62.5% boys, 11.2 ± 3.1 years) from East Denmark and 58 patients in the control group (57% boys, 11.0 ± 3.2 years) from West Denmark. Eight children from the control group withdrew from participation. The groups were comparable in anthropometrics and cancer diagnoses (p > 0.05). The intervention consisted of (i) supervised in-hospital physical activity from diagnosis and throughout intensive treatment, (ii) 90-min general educational session on cancer and therapy in the child's school class, and (iii) selection of two classmates as ambassadors who took turns to support the child's physical training during the daytime. The primary outcome was cardiorespiratory fitness (VO2peak, mL/min/kg) at 6 months after diagnosis (sex, age, diagnosis adjusted). Secondary outcomes were sit-to-stand, timed-up-and-go, handgrip strength, and balance test scores. RESULTS: Ambassadors were identified for all, and 2542 individual and 621 group training sessions were held. VO2peak deteriorated over time in the control group (- 0.17 [95% CI - 0.32 to - 0.02] per week, p = 0.02), but not in the intervention group (p = 0.14). At 6 months from diagnosis, VO2peak was higher in the intervention group (29.6 ± 5.6 mL/kg/min) than in the control group (22.1 ± 5.6 mL/kg/min) (p = 0.01), and the intervention group had a better physical function at 3 and 6 months (p < 0.0001). CONCLUSIONS: Peer-supported, supervised, in-hospital, physical activity is safe and feasible in children with cancer during treatment. Further, the results suggest that the intervention might mitigate impairments in cardiorespiratory fitness during treatment in children with cancer. TRIAL REGISTRATION: The study was prospectively registered on the 11 January 2013. Clinicaltrial.gov NCT01772849 and NCT01772862 .

Physical activity attenuates metabolic risk of adolescents with overweight or obesity: the ICAD multi-country study.

BACKGROUND: Although the benefits of physical activity (PA) at an early age are well established, there is no robust evidence of the role of PA as well as its intensities in attenuating the association between weight status and metabolic risk among adolescents. In this investigation, we analyzed the association between weight status, intensities of PA, and metabolic risk among adolescents. METHODS: Data from six cross-sectional studies in the International Children's Accelerometry Database were used (N = 5216 adolescents; boys 14.6 ± 2.1 years and girls 14.7 ± 2.0 years). Weight status was assessed and classified according to body mass index. Fasting glucose, triglycerides, inverse high-density lipoprotein cholesterol, and blood pressure composed the metabolic risk indicator (z-score). PA was measured by accelerometers. The estimated age of peak height velocity was used as a covariate for somatic maturation. RESULTS: We observed that increase in weight status showed a strong positive relationship with metabolic risk. However, adolescents with overweight or obesity in the highest tertile of PA (moderate-to-vigorous and vigorous intensity) showed a similar metabolic risk score as the normal weight groups. Moderate intensity PA seemed related to metabolic risk even within some categories of vigorous PA. CONCLUSIONS: We conclude that PA attenuates the metabolic risk of adolescents with overweight or obesity. Although this attenuation is largely explained by vigorous PA, moderate intensity seems also important for better metabolic profile.

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 and Sedentary Patterns on Cardiometabolic Outcomes in the Transition to Adolescence: International Children's Accelerometry Database 2.0.

OBJECTIVE: To examine the associations of changes in physical activity and sedentary patterns with changes in cardiometabolic outcomes from childhood to adolescence. STUDY DESIGN: Youth from the International Children's Accelerometry Database (n = 1088; 55% girls), aged 8-13 years and followed for ∼4 years, were used in this analysis. Hip-mounted accelerometers were used and all physical activity intensities were expressed as the % of total wear-time. Sedentary time was separated into time spent in bouts <10 minutes and ≥10 minutes. A composite z score for cardiometabolic risk (CMR score) was computed by summing the standardized values for systolic and diastolic blood pressure, triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), and the inverse high-density lipoprotein cholesterol. Multivariate analyses were performed using adjusted linear regression models. RESULTS: Increase in sedentary time was unfavorably associated with changes in CMR score (ß = 0.021; CI 0.004-0.037), TG (ß = 0.003; CI 0.001-0.005), and diastolic blood pressure (ß = 0.068; CI 0.009-0.128). Decrease in moderate-to-vigorous physical activity was unfavorably associated with changes in LDL-c (ß = -0.009; CI -0.017 to -0.001) and TG (ß = -0.007; CI -0.013 to -0.001). Increase in ≥10 minutes sedentary time was unfavorably associated with changes in CMR score (ß = 0.017; CI 0.004-0.030), LDL-c (ß = 0.003; CI 0.000-0.005), and TG (ß = 0.003; CI 0.000-0.004). Decrease in light-intensity physical activity was unfavorably associated with changes in CMR score (ß = -0.020; CI = -0.040 to 0.000). CONCLUSIONS: More physical activity and less prolonged sedentary time are beneficial for cardiometabolic health in youth transitioning to adolescence.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents.

BACKGROUND: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. METHODS: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2-18 years) from 18 different European countries. RESULTS: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. CONCLUSIONS: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

The multivariate physical activity signature associated with metabolic health in children and youth: An International Children's Accelerometry Database (ICAD) analysis.

There is solid evidence for an association between physical activity and metabolic health outcomes in children and youth, but for methodological reasons most studies describe the intensity spectrum using only a few summary measures. We aimed to determine the multivariate physical activity intensity signature associated with metabolic health in a large and diverse sample of children and youth, by investigating the association pattern for the entire physical intensity spectrum. We used pooled data from 11 studies and 11,853 participants aged 5.8-18.4 years included in the International Children's Accelerometry Database. We derived 14 accelerometry-derived (ActiGraph) physical activity variables covering the intensity spectrum (from 0-99 to ≥8000 counts per minute). To handle the multicollinearity among these variables, we used multivariate pattern analysis to establish the associations with indices of metabolic health (abdominal fatness, insulin sensitivity, lipid metabolism, blood pressure). A composite metabolic health score was used as the main outcome variable. Associations with the composite metabolic health score were weak for sedentary time and light physical activity, but gradually strengthened with increasing time spent in moderate and vigorous intensities (up to 4000-5000 counts per minute). Association patterns were fairly consistent across sex and age groups, but varied across different metabolic health outcomes. This novel analytic approach suggests that vigorous intensity, rather than less intense activities or sedentary behavior, are related to metabolic health in children and youth.

The causal pathway effects of a physical activity intervention on adiposity in children: The KISS Study cluster randomized clinical trial.

BACKGROUND: Very little information on the potential mechanisms of the physical activity interventions effects on adiposity is available. We evaluated the possible mediating factors of a physical activity school-based intervention on the sum of skinfolds in children. METHODS: This is a cluster randomized trial, secondary analysis of the KISS study. Children (n = 499) from the first and fifth grades were randomly assigned to intervention or control group. Adiposity was estimated by four skinfolds, aerobic fitness assessed by the shuttle run test, and insulin, triglycerides, total cholesterol, high-density lipoprotein (HDL), and glucose collected via fasting blood samples. RESULTS: The intervention affected aerobic fitness (0.140 SD, 95% CI 0.011 to 0.270), triglycerides (0.217 SD, 95% CI -0.409 to -0.025), cholesterol/HDL ratio (-0.191 SD, 95% CI -0.334 to -0.047), glucose (-0.330 SD, 95% CI -0.538 to -0.121), and skinfolds (-0.122 SD, 95% CI -0.189 to -0.056). No intervention effect on insulin was found. We observed that changes in aerobic fitness impacted children's triglycerides and cholesterol/HDL ratio and consecutively the glucose levels mediating 30% of the intervention effect on skinfolds. CONCLUSIONS: Our findings provided evidence of the positive metabolic distress caused by a physical activity intervention on adiposity levels in children.

No additional long-term effect of group vs individual family intervention in the treatment of childhood obesity-A randomised trial.

AIM: Long-term evaluations of childhood obesity treatments are needed. We examined changes in weight and cardiometabolic risk 1 year after children completed individual family or group-based weight management interventions. METHODS: In 2009-2010, 6- to 12-year-old children with overweight or obesity from Finnmark and Troms (Norway) were recruited after media coverage and randomised to 24 months of individual family (n = 49) or group intervention (n = 48). Individual family intervention included counselling by a paediatric hospital team and a public health nurse in the local community. Group intervention included meetings with other families and a multidisciplinary hospital team, weekly physical activity sessions and a family camp. The primary outcome body mass index (BMI) and cardiometabolic risk factors were analysed 12 months after intervention. RESULTS: From baseline to 36 months, children's BMI increased 3.0 kg/m2 in individual family and 2.1 kg/m2 in group intervention (between-group -0.9kg/m2 , P = 0.096). Data were available from 62 children (64%). Between-group differences in C peptide (P = 0.01) were detected in favour of group intervention. Pooled data from both treatment groups showed continued decrease in BMI standard deviation score (P < 0.001). CONCLUSION: No between-group difference in BMI was observed 12 months after intervention. Both groups combined showed sustained decrease in BMI standard deviation score.

Can ß2-agonists have an ergogenic effect on strength, sprint or power performance? Systematic review and meta-analysis of RCTs.

OBJECTIVES: We aimed to examine the effect of ß2-agonists on anaerobic performance in healthy non-asthmatic subjects. DESIGN: Systematic review and meta-analysis. ELIGIBILITY CRITERIA: We searched four databases (PubMed, Embase, SPORTDiscus and Web of Science) for randomised controlled trials, published until December 2019, examining the effect of ß2-agonists on maximal physical performance lasting 1 min or shorter. Data are presented as standardised difference in mean (SDM) with 95% confidence intervals (95% CI). RESULTS: 34 studies were included in the present meta-analysis. The studies include 44 different randomised and placebo-controlled comparisons with ß2-agonists comprising 323 participants in crossover trials, and 149 participants in parallel trials. In the overall analyses, ß2-agonists improved anaerobic performance by 5% (SDM 0.29, 95% CI 0.16 to 0.42), but the effect was related to dose and administration route. In a stratified analysis, the SDM was 0.14 (95% CI 0.00 to 0.28) for approved ß2-agonists and 0.46 (95% CI 0.24 to 0.68) for prohibited ß2-agonists, respectively. Furthermore, SDM was 0.16 (95% CI 0.02 to 0.30) for inhaled administration and 0.51 (95% CI 0.25 to 0.77) for oral administration, respectively, and 0.20 (95% CI 0.07 to 0.33) for acute treatment and 0.50 (95% CI 0.20 to 0.80) for treatment for multiple weeks. Analyses stratified for the type of performance showed that strength (0.35, 95% CI 0.15 to 0.55) and sprint (0.17, 95% CI 0.06 to 0.29) performance were improved by ß2-agonists. CONCLUSION/IMPLICATION: Our study shows that non-asthmatic subjects can improve sprint and strength performance by using ß2-agonists. It is uncertain, however, whether World Anti-Doping Agency (WADA)-approved doses of ß2-agonists improve performance. Our results support that the use of ß2-agonists should be controlled and restricted to athletes with documented asthma. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018109223.

Interpretation of associations between the accelerometry physical activity spectrum and cardiometabolic health and locomotor skills in two cohorts of children using raw, normalized, log-transformed, or compositional data.

It is discussed whether associations between accelerometer-derived physical activity intensities and outcomes should be analysed as absolute or relative data. The aim of the present study was to compare interpretation of association patterns of spectrum physical activity descriptions with outcome using raw, normalized, log-transformed, or compositional data. We used two datasets including 1) 841 schoolchildren and a cardiometabolic health outcome and 2) 1081 preschool children and a locomotor skill outcome. Accelerometry (ActiGraph GT3X+) data were described using multiple variables across the intensity spectrum. We varied the binning of variables to examine sensitivity of the compositional analyses to changes in the distribution centre. We used multivariate pattern analysis for all analyses and interpretations of data. Analyses of absolute (i.e., non-compositional) data showed weak associations for lower intensities and strongest associations with cardiometabolic health and locomotor skills for vigorous intensities. The same association patterns were partly observed for the compositional data, but association patterns were in some cases conflicting. The binning of variables had a major influence on associations for compositional data, but not for absolute data, meaning that conclusions depend on the operationalization of compositional data. These differences challenge and confuse interpretation of association patterns derived from the different approaches.

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.