Tracking of total sedentary time and sedentary patterns in youth: a pooled analysis using the International Children's Accelerometry Database (ICAD).

BACKGROUND: To gain more understanding of the potential health effects of sedentary time, knowledge is required about the accumulation and longitudinal development of young people's sedentary time. This study examined tracking of young peoples' total and prolonged sedentary time as well as their day-to-day variation using the International Children's Accelerometry Database. METHODS: Longitudinal accelerometer data of 5991 children (aged 4-17y) was used from eight studies in five countries. Children were included if they provided valid (≥8 h/day) accelerometer data on ≥4 days, including ≥1 weekend day, at both baseline and follow-up (average follow-up: 2.7y; range 0.7-8.2). Tracking of total and prolonged (i.e. ≥10-min bouts) sedentary time was examined using multilevel modelling to adjust for clustering of observations, with baseline levels of sedentary time as predictor and follow-up levels as outcome. Standardized regression coefficients were interpreted as tracking coefficients (low: < 0.3; moderate: 0.3-0.6; high: > 0.6). RESULTS: Average total sedentary time at study level ranged from 246 to 387 min/day at baseline and increased annually by 21.4 min/day (95% confidence interval [19.6-23.0]) on average. This increase consisted almost entirely of prolonged sedentary time (20.9 min/day [19.2-22.7]). Total (standardized regression coefficient (B) = 0.48 [0.45-0.50]) and prolonged sedentary time (B = 0.43 [0.41-0.45]) tracked moderately. Tracking of day-to-day variation in total (B = 0.04 [0.02-0.07]) and prolonged (B = 0.07 [0.04-0.09]) sedentary time was low. CONCLUSION: Young people with high levels of sedentary time are likely to remain among the people with highest sedentary time as they grow older. Day-to-day variation in total and prolonged sedentary time, however, was rather variable over time.

The Copenhagen Consensus Conference 2016: children, youth, and physical activity in schools and during leisure time.

From 4 to 7 April 2016, 24 researchers from 8 countries and from a variety of academic disciplines gathered in Snekkersten, Denmark, to reach evidence-based consensus about physical activity in children and youth, that is, individuals between 6 and 18 years. Physical activity is an overarching term that consists of many structured and unstructured forms within school and out-of-school-time contexts, including organised sport, physical education, outdoor recreation, motor skill development programmes, recess, and active transportation such as biking and walking. This consensus statement presents the accord on the effects of physical activity on children's and youth's fitness, health, cognitive functioning, engagement, motivation, psychological well-being and social inclusion, as well as presenting educational and physical activity implementation strategies. The consensus was obtained through an iterative process that began with presentation of the state-of-the art in each domain followed by plenary and group discussions. Ultimately, Consensus Conference participants reached agreement on the 21-item consensus statement.

Associations of Adiposity and Aerobic Fitness with Executive Function and Math Performance in Danish Adolescents.

OBJECTIVE: To examine the associations of adiposity and aerobic fitness with executive function and math performance in Danish adolescents. STUDY DESIGN: Cross-sectional analyses were conducted with data on 525 adolescents attending sixth and seventh grades from 14 schools in the 5 main regions of Denmark. A modified Eriksen flanker task was used to assess inhibitory control, a key aspect of executive function. Academic performance was assessed by a customized math test. Aerobic fitness was assessed by an intermittent shuttle-run test (Andersen test). RESULTS: Body mass index (BMI) was negatively associated with accuracy on incongruent trials during the flanker task (P = .005). A higher BMI was associated with a larger accuracy interference score (P = .01). Similarly, waist circumference (WC) was negatively associated with accuracy on incongruent trials (P = .008). A higher WC was associated with a larger reaction time (RT) interference score (P = .02) and accuracy interference score (P = .009). Higher aerobic fitness was associated with a faster RT on congruent trials (P = .009) and incongruent trials (P = .003). Higher aerobic fitness was associated with a smaller RT interference score (P = .04). Aerobic fitness was positively associated with math score (P < .001). BMI and WC were not associated with math score (P > .05). CONCLUSIONS: These results suggest that aerobic fitness is positively associated with both inhibitory control and math performance in adolescents. Adiposity is negatively associated with inhibitory control in adolescents. Adiposity is not associated with math performance.

Objectively measured physical activity and sedentary time in youth: the International children's accelerometry database (ICAD).

BACKGROUND: Physical activity and sedentary behaviour in youth have been reported to vary by sex, age, weight status and country. However, supporting data are often self-reported and/or do not encompass a wide range of ages or geographical locations. This study aimed to describe objectively-measured physical activity and sedentary time patterns in youth. METHODS: The International Children's Accelerometry Database (ICAD) consists of ActiGraph accelerometer data from 20 studies in ten countries, processed using common data reduction procedures. Analyses were conducted on 27,637 participants (2.8-18.4 years) who provided at least three days of valid accelerometer data. Linear regression was used to examine associations between age, sex, weight status, country and physical activity outcomes. RESULTS: Boys were less sedentary and more active than girls at all ages. After 5 years of age there was an average cross-sectional decrease of 4.2% in total physical activity with each additional year of age, due mainly to lower levels of light-intensity physical activity and greater time spent sedentary. Physical activity did not differ by weight status in the youngest children, but from age seven onwards, overweight/obese participants were less active than their normal weight counterparts. Physical activity varied between samples from different countries, with a 15-20% difference between the highest and lowest countries at age 9-10 and a 26-28% difference at age 12-13. CONCLUSIONS: Physical activity differed between samples from different countries, but the associations between demographic characteristics and physical activity were consistently observed. Further research is needed to explore environmental and sociocultural explanations for these differences.

A prospective study of screen time in adolescence and depression symptoms in young adulthood.

OBJECTIVES: The purpose of this study was to examine the association between screen time in adolescence and depressive symptoms in young adulthood in a population-based cohort study of Danish adolescents. METHODS: Data were from a cohort of adolescents who were followed-up in young adulthood for a period of up to 12 years (1997-2010, mean 8.8 years, n=435). Information on television viewing, computer use, total screen time and other determinants of depression were obtained in adolescence. Depressive symptoms were obtained in young adulthood using the Major Depression Inventory (MDI) and classified as mild, moderate or severe depression. Mixed regression models were used to examine the associations, with adjustment for major confounders. RESULTS: In multivariable adjusted analyses, each additional hour/day spent watching television or screen viewing in adolescence was associated with 1.36 (95% CI 0.73-1.98) and 1.05 (95% CI 0.50-1.60), respectively, greater MDI depression summary score in young adulthood (p<0.001). In logistic regression models, each additional hour/day spent watching television or screen viewing was associated with 1.64 (95% CI 1.18-2.27) and 1.58 (95% CI 1.18-2.12), respectively, greater odds of prevalent depression in young adulthood, and dose-response relationships were indicated. Additional adjustment for either cardiorespiratory fitness or BMI did not materially change the results. No significant associations were observed between adolescent computer use and depressive symptoms in young adulthood. CONCLUSIONS: Limiting screen time, particularly television viewing, during adolescence may be important for preventing depression in young adulthood.

Association between dairy intake and caries among children and adolescents. results from the Danish EYHS follow-up study.

The aim of this paper was to investigate associations between the intake of dairy products and the development in caries (DMFS, decayed, missing and filled surfaces) among children/adolescents over a period of 3 and 6 years, and to investigate whether dairy intake protects against caries incidence. A total of 68.9% of the children were caries free at the age of 9 compared with 34.0% of the adolescents at the age of 15 (measured as DMFS = 0). A larger percentage of children/adolescents with a dairy intake above the mean were caries free compared with the group of children/adolescents with an intake below the mean (72.8 vs. 65.8% at age 9 and 41.1 vs. 30.7% at age 15). The results from the generalized estimation equation showed that dairy and milk intake, as well as intakes of components of dairy such as dairy calcium, whey and casein, was generally inversely associated with childhood/adolescent caries experience (measured as DMFS). With regard to caries incidence, the same inverse association was found for incidence over a period of 3 years and for incidence over 6 years, but the results were only statistically significant for the 3-year incidence and for the unadjusted models of the 6-year incidence. This study found that previous dairy intake, as well as milk intake or intake of dairy components, may be a predictor of future risk of caries measured by the DMFS count level. This relationship was inverse, meaning that a high intake of dairy products was associated with less future caries development. However, more studies on larger cohorts are needed to confirm these findings.

Moderate-and-vigorous physical activity from adolescence to adulthood and subclinical atherosclerosis in adulthood: prospective observations from the European Youth Heart Study.

AIM: To investigate the independent associations between mean exposure to or the change in moderate-and-vigorous physical activity (PA) from adolescence to adulthood and subclinical atherosclerosis in adulthood. METHODS: This was a prospective cohort study among Danish boys and girls (N=277) followed for up to 12 years (age 15.7 (0.4) at baseline) enrolled in the European Youth Heart Study. PA intensity was objectively measured at baseline and follow-up, and ultrasonography was performed on the Carotid arteries at follow-up. Data on carotid intima-media thickness (cIMT), Carotid Compliance and Young's Elastic Modules were used as outcome measures. RESULTS: In the multivariable analyses (adjusted for personal-lifestyle and demographic factors) the mean exposure to moderate-and-vigorous PA from adolescence to adulthood was negatively associated with Young's Elastic Modules (ß=-0.001×10(3) kPa (95% CI -0.0015 to -0.0002), p=0.02) and positively associated with Carotid Compliance (ß=0.004 mm(2) kPa(-1) (95% CI 0.002 to 0.008), p=0.003) and cIMT (ß=0.0003 mm (95% CI 0.00001 to 0.0007), p=0.013). Increases in moderate-and-vigorous PA from adolescence to adulthood were negatively associated with Young's Elastic Modules in adulthood (ß=-0.00007×10(3) kPa (95% CI -0.0012 to -0.0001), p=0.01). Furthermore, participants with the largest decline in moderate-and-vigorous PA from adolescence to adulthood displayed significantly less compliant arteries compared with the remaining sample (p<0.05). CONCLUSIONS: High mean exposure to moderate-and-vigorous PA levels and increases herein were independently associated with lower levels of carotid arterial stiffness in adulthood.

Muscle strength in youth and cardiovascular risk in young adulthood (the European Youth Heart Study).

BACKGROUND: Whether muscle strength in youth is related to cardiovascular risk later in life independent of cardiorespiratory fitness is unclear. METHODS: We examined the independent association of isometric muscle strength in youth with cardiovascular risk factors in young adulthood using data from the Danish European Youth Heart Study; a population-based prospective cohort study among boys and girls (n=332) followed for up to 12 years. In youth maximal voluntary contractions during isometric back extension and abdominal flexion were determined using a strain-gauge dynamometer and cardiorespiratory fitness was obtained from a maximal cycle ergometer test. Cardiovascular risk factors were obtained in youth and in young adulthood. Associations were examined using multivariable-adjusted regression models including major confounding factors. RESULTS: Each 1 SD difference in isometric muscle strength in youth (0.17 N/kg) was inversely associated with body mass index (BMI; -0.60 kg/m(2), 95% CI -0.97 to -0.22), triglyceride (-0.09 mmol/l, 95% CI -0.16 to -0.02), diastolic blood pressure (BP) (-1.22 mm Hg, 95% CI -2.15 to -0.29) and a composite cardiovascular risk factor score (-0.61 SD, 95% CI -1.03 to -0.20) in young adulthood in multivariable-adjusted analyses including fitness. Associations to triglyceride, diastolic BP and the cardiovascular risk factor score remained with additional adjustment for waist circumference or BMI. Each 1 SD difference in isometric muscle strength in youth was significantly associated with 0.59 (95% CI 0.40 to 0.87) lower odds of general overweight/obesity in young adulthood (p=0.007) and was marginally associated with incident raised BP, raised triglyceride and low high-density lipoprotein cholesterol. CONCLUSIONS: This study suggests that greater isometric muscle strength in youth is associated with lower levels of cardiovascular risk factors in young adulthood independent of fitness, adiposity and other confounding factors.

LCoMotion - Learning, Cognition and Motion; a multicomponent cluster randomized school-based intervention aimed at increasing learning and cognition - rationale, design and methods.

BACKGROUND: The aim of the study; LCoMotion - Learning, Cognition and Motion was to develop, document, and evaluate a multi-component physical activity (PA) intervention in public schools in Denmark. The primary outcome was cognitive function. Secondary outcomes were academic skills, body composition, aerobic fitness and PA. The primary aim of the present paper was to describe the rationale, design and methods of the LCoMotion study. METHODS/DESIGN: LCoMotion was designed as a cluster-randomized controlled study. Fourteen schools from all five regions in Denmark participated. All students from 6th and 7th grades were invited to participate (n = 869) and consent was obtained for 87% (n = 759). Baseline measurements were obtained in November/December 2013 and follow-up measurements in May/June 2014. The intervention lasted five months and consisted of a "package" of three main components: PA during academic lessons, PA during recess and PA homework. Furthermore a cycling campaign was conducted during the intervention period. Intervention schools should endeavor to ensure that students were physically active for at least 60 min every school day. Cognitive function was measured by a modified Eriksen flanker task and academic skills by a custom made mathematics test. PA was objectively measured by accelerometers (ActiGraph, GT3X and GT3X+) and aerobic fitness assessed by an intermittent shuttle-run test (the Andersen intermittent running test). Furthermore, compliance with the intervention was assessed by short message service (SMS)-tracking and questionnaires were delivered to students, parents and teachers. DISCUSSION: LCoMotion has ability to provide new insights on the effectiveness of a multicomponent intervention on cognitive function and academic skills in 6th and 7th grade students. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02012881 (10/10/2013).

Physical activity and motor skills in children attending 43 preschools: a cross-sectional study.

BACKGROUND: Little is known about health characteristics and the physical activity (PA) patterns in children attending preschools. The objective of this study was to describe the gender differences in relation to body mass index (BMI), motor skills (MS) and PA, including PA patterns by the day type and time of day. Additionally, the between-preschool variation in mean PA was estimated using the intraclass correlation. METHODS: We invited 627 children 5-6 years of age attending 43 randomly selected preschools in Odense, Denmark. Aiming and catching MS was assessed using subtests of the Movement Assessment Battery for Children (Second Edition) and motor coordination MS was assessed by the Kiphard-Schilling body coordination test, Körperkoordination Test für Kinder. PA was measured using accelerometry. The PA patterns were analysed using mixed models. RESULTS: No gender differences in the BMI or norm-referenced MS risk classification, or the average weekly PA level or patterns of PA were observed. However, boys performed better in the aiming and catching score (p < 0.01) and in the motor coordination score (p < 0.05) on average. Girls performed better in the balance subtest (p < 0.001). Relative to the norm-referenced classification of MS, the Danish sample distribution was significantly well for aiming and catching but poorer for the motor coordination test.The total sample and the least active children were most active on weekdays, during preschool time and in the late afternoon at the weekend. However, a relatively larger decrease in PA from preschool to weekday leisure time was observed in children in the lowest PA quartile compared to children in the highest PA quartile. Finally, the preschool accounted for 19% of the total variance in PA, with significant gender differences. CONCLUSIONS: Results of this study could provide a valuable reference material for studies monitoring future trends in obesity, MS and PA behaviour in Denmark and other countries.Knowledge about sources of variation in PA among preschool children is scarce and our findings need to be replicated in future studies. A potentially important finding is the large between-preschool variation in PA, indicating that especially girls are very susceptible to the environment offered for PA during preschool attendance.

Associations between objectively measured physical activity intensity in childhood and measures of subclinical cardiovascular disease in adolescence: prospective observations from the European Youth Heart Study.

BACKGROUND AND AIM: No prospective studies have investigated the association between physical activity (PA) and carotid subclinical cardiovascular disease across childhood. Therefore, the primary aim was to investigate the association between PA intensity across childhood and carotid intima media thickness (cIMT) and stiffness in adolescence. Second, we included a clustered cardiovascular disease risk score as outcome. METHODS: This was a prospective study of a sample of 254 children (baseline age 8-10 years) with a 6-year follow-up. The mean exposure and the change in minutes of moderate-and-vigorous and vigorous PA intensity were measured using the Actigraph activity monitor. Subclinical cardiovascular disease was expressed as cIMT, carotid arterial stiffness and secondarily as a metabolic risk z-score including the homoeostasis model assessment score of insulin resistance, triglycerides, total cholesterol to high-density lipoprotein ratio, inverse of cardiorespiratory fitness, systolic blood pressure and the sum of four skinfolds. RESULTS: No associations were observed between PA intensity variables and cIMT or carotid arterial stiffness (p>0.05). Neither change in PA intensity (moderate-and-vigorous nor vigorous) nor mean minutes of moderate-and-vigorous PA intensity was associated to the metabolic risk z-score in adolescence (p>0.05). However, a significant inverse association was observed between mean minutes of vigorous PA and the metabolic risk z-score in adolescence independent of gender and biological maturity (standard ß=-0.19 p=0.007). CONCLUSIONS: A high mean exposure to, or changes in, minutes spent at higher PA intensities across childhood was not associated to cIMT or stiffness in the carotid arteries in adolescence. Our observations suggest that a high volume of vigorous PA across childhood independently associated with lower metabolic cardio vascular disease risk in adolescence.

A comparative analysis of movement and physical activity in early childhood teacher education policy in five Nordic countries.

Introduction: The aim of this study is to investigate the integration of movement and physical activity (MoPA) within Early Childhood Teacher Education (ECTE) policies across Denmark, Finland, Iceland, Norway, and Sweden. This knowledge can inform the development of ECTE policies and practices that promote MoPA in Early Childhood Education and Care (ECEC) in Nordic countries and other countries worldwide. Methods: In this study, a Nordic cross-national network of researchers collaborated in investigating policy documents at the national and university levels, which govern the education of ECEC teachers. This study was inspired by the Non-affirmative Theory of Education, which provides a framework for understanding the various influences on curricular development in higher education. Based on this, a four-step comparative analytical process of national and university documents across the Nordic countries was conducted. It included keyword search for MoPA related courses and a qualitative description of MoPA in ECTE. Thus, a combination of investigations of policy documents at the national and university level and expert knowledge set a solid foundation for international comparison. Results: The comparative analysis of MoPA in ECTE reveals diverse approaches influenced by national and university policies. A central theme is the variability in MoPA integration across these nations. Finland and Norway prioritize MoPA with independent mandatory courses. In Iceland, compulsory MoPA courses exist at one of two universities, and in Sweden at three out of 19. All university colleges in Denmark offer an elective course. Furthermore, learning objectives related to MoPA are, to varying degrees, part of the internships in the countries, with Sweden being an exception. In the participating countries, the teachers decide the content of the MoPA courses with little guidance, support, and agreement on essential MoPA content within and across the ECTE's. Norway has established guidelines, and in Finland, there is a network of ECTE Physical Education (PE) educators, which, to some degree, increases the consistency and quality of MoPA in education. Discussion: The Nordic countries present diverse MoPA integration approaches rooted in national policies and educational traditions. The findings emphasize the necessity of independent and mandatory MoPA courses, integration of MoPA into internships and promoting networks across the educational and academic sectors to equip future early childhood educators with competencies for fostering physical activity, motor development and children's well-being.

Tracking of clustered cardiovascular disease risk factors from childhood to adolescence.

BACKGROUND: Clustering of cardiovascular disease (CVD) risk factors has been found in children as young as 9 y of age. However, the stability of this clustering over the course of childhood has yet to be determined. The purpose of this study was to determine the tracking of clustered CVD risk from young school age through adolescence and to examine differences in tracking between levels of overweight/obesity and cardiorespiratory fitness (VO(2peak)). METHODS: Beginning at 6 y, children (n = 434) were measured three times in 7 y. Anthropometrics, blood pressure, and VO(2peak) were measured. Fasting blood samples were analyzed for CVD risk factors. A clustered risk score (z-score) was constructed by adding sex-specific z-scores for blood pressure, homeostatic model assessment (HOMA-IR), triglyceride (TG), skinfolds, and negative values of high-density lipoprotein cholesterol (HDLc) and VO(2peak). RESULTS: Significant tracking coefficients were found between clustered z-score at all time intervals (r = 0.514, 0.559, and 0.381 between ages 6-9, 9-13, and 6-13 y, respectively, all P < 0.0001). Tracking was higher for low-fit children, whereas no clear pattern was found for different levels of body fat. CONCLUSION: We found that clustered z-score is a fairly stable characteristic through childhood. Implementation of preventive strategies could therefore start at early school age.

Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.

The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.

Between-school variation in physical activity, aerobic fitness, and organized sports participation: a multi-level analysis.

A large proportion of a child's day is spent at school interacting with certain physical surroundings, teachers, and school friends. Thus, schools could have a marked impact on establishing physical activity habits. The aim of the present study was to assess between-school variation in physical activity, aerobic fitness, and organized sports participation. Altogether, we tested 1766 nine- and fifteen-year-old children attending 242 school classes at 35 different schools in Denmark in 1997-2003. The intra-class correlation coefficient (ICC) for objectively assessed physical activity ranged between 0.06 and 0.18 depending on the dimension of physical activity and the time considered (i.e. school time vs. leisure time). For aerobic fitness, an ICC of 0.10 was observed, whereas that for organized sports participation ranged between 0.01 and 0.10 depending on the age group. Studying between-school variation in physical activity provides information about the extent to which children adjust their physical activity habits according to the social and environmental circumstances that they share, and helps to plan future school-based physical activity studies, especially in terms of sample size and power calculation.

Inter-relationships among physical activity, body fat, and motor performance in 6- to 8-year-old Danish children.

This study examined the interrelationships among physical activity (PA), percent body fat (%BF), and motor performance (MP) in 498 6- to 8-year-old Danish children. PA was assessed by accelerometer, %BF was calculated from skinfolds, and the Koordinations Test für Kinder along with a throwing accuracy test was used to assess MP. PA was not correlated with %BF, but was significantly correlated with MP. The strongest correlations existed between %BF and MP. Low %BF/High PA had higher MP scores compared with High %BF/Low PA, and within the High %BF groups MP was higher in the High PA versus Low PA group. When comparing PA by %BF and MP groups, boys in the Low %BF/High MP had higher PA than both the Low %BF/Low MP and High %BF/Low MP groups. In girls, PA was highest in the High %BF/High MP group. This study highlights the complex interrelationships among PA, %BF, and MP in children and the need to develop fundamental motor skills during childhood.

Recommended aerobic fitness level for metabolic health in children and adolescents: a study of diagnostic accuracy.

OBJECTIVE: To define the optimal cut-off for low aerobic fitness and to evaluate its accuracy to predict clustering of risk factors for cardiovascular disease in children and adolescents. DESIGN: Study of diagnostic accuracy using a cross-sectional database. SETTING: European Youth Heart Study including Denmark, Portugal, Estonia and Norway. PARTICIPANTS: 4500 schoolchildren aged 9 or 15 years. MAIN OUTCOME MEASURE: Aerobic fitness was expressed as peak oxygen consumption relative to bodyweight (mlO(2)/min/kg). RESULTS: Risk factors included in the composite risk score (mean of z-scores) were systolic blood pressure, triglyceride, total cholesterol/HDL-cholesterol ratio, insulin resistance and sum of four skinfolds. 14.5% of the sample, with a risk score above one SD, were defined as being at risk. Receiver operating characteristic analysis was used to define the optimal cut-off for sex and age-specific distribution. In girls, the optimal cut-offs for identifying individuals at risk were: 37.4 mlO(2)/min/kg (9-year-old) and 33.0 mlO(2)/min/kg (15-year-old). In boys, the optimal cut-offs were 43.6 mlO(2)/min/kg (9-year-old) and 46.0 mlO(2)/min/kg (15-year-old). Specificity (range 79.3-86.4%) was markedly higher than sensitivity (range 29.7-55.6%) for all cut-offs. Positive predictive values ranged from 19% to 41% and negative predictive values ranged from 88% to 90%. The diagnostic accuracy for identifying children at risk, measured by the area under the curve (AUC), was significantly higher than what would be expected by chance (AUC >0.5) for all cut-offs. CONCLUSIONS: Aerobic fitness is easy to measure, and is an accurate tool for screening children with clustering of cardiovascular risk factors. Promoting physical activity in children with aerobic fitness level lower than the suggested cut-points might improve their health.

Predictors of VO2Peak in children age 6- to 7-years-old.

This study investigated the predictors of aerobic fitness (VO2PEAK) in young children on a population-base. Participants were 436 children (229 boys and 207 girls) aged 6.7 ± 0.4 yrs. VO2PEAK was measured during a maximal treadmill exercise test. Physical activity was assessed by accelerometers. Total body fat and total fat free mass were estimated from skinfold measurements. Regression analyses indicated that significant predictors for VO2PEAK per kilogram body mass were total body fat, maximal heart rate, sex, and age. Physical activity explained an additional 4-7%. Further analyses showed the main contributing factors for absolute values of VO2PEAK were fat free mass, maximal heart rate, sex, and age. Physical activity explained an additional 3-6%.

Movement and Physical Activity in Early Childhood Education and Care Policies of Five Nordic Countries.

The purpose of this study was to examine the values of movement and physical activity (MoPA) using government policy documents (e.g., laws and curricula) on early childhood education and care (ECEC) from Denmark, Finland, Iceland, Norway, and Sweden. This descriptive, comparative study was designed based on curriculum theory and used word count and content analyses to identify similarities and differences in the occurrence of MoPA in the ECEC policies of Nordic countries. Seven terms were identified as MoPA-related in Nordic policy documents. These terms occurred in various content contexts: development, environment, expression, health and well-being, learning and play, albeit sparsely. MoPA was referred to as both a goal in and of itself and as a means of achieving other goals (e.g., learning or development in another area). Formulations specifically dedicated to MoPA as a goal were present in the Danish and Finnish curricula and, to some extent, also in the Norwegian curriculum, while the Icelandic and Swedish curricula mentioned MoPA mostly as a means. Findings indicated that MoPA, which is important for children's development, health, and well-being, is a low-priority value, to varying degrees, in the ECEC policies enacted by Nordic countries and the guidance provided to educators and stakeholders therein is inexplicit.

The association between aerobic fitness and physical activity in children and adolescents: the European youth heart study.

The link between aerobic fitness and physical activity in children has been studied in a number of earlier studies and the results have generally shown weak to moderate correlations. This overall finding has been widely questioned partly because of the difficulty in obtaining valid estimates of physical activity. This study investigated the cross-sectional and longitudinal relationship between aerobic fitness and physical activity in a representative sample of 9 and 15-year-old children (n = 1260 cross-sectional, n = 153 longitudinal). The specific goal was to improve past studies using an objective method of activity assessment and taking into account a number of major sources of error. Data came from the Danish part of the European youth heart study, 1997-2003. The cross-sectional results generally showed a weak to moderate association between aerobic fitness and physical activity with standardized regression coefficients ranging from 0.14 to 0.33. The longitudinal results revealed a tendency towards an interaction effect of baseline physical activity on the relationship between changes in physical activity and aerobic fitness. Moderate to moderately strong regression effect sizes were observed in the lower quadrant of baseline physical activity compared to weak effect sizes in the remaining quadrants. In conclusion, the present study confirms earlier findings of a weak to moderate association between aerobic fitness and physical activity in total population of children. However, the study also indicates that inactive children can achieve notable increase in aerobic fitness by increasing their habitual physical activity level. A potential physiological explanation for these results is highlighted.