Secular trends in physical fitness and obesity in Danish 9-year-old girls and boys: Odense School Child Study and Danish substudy of the European Youth Heart Study

Secular trends in 20 m shuttle run test performance of 14- to 15-year-old adolescents from 1995 to 2020

PURPOSE

To investigate whether Finnish adolescents' cardiorespiratory fitness measured using the 20 m shuttle run test (20mSRT) changed between 1995 and 2020 and to examine between-group variation in the five datasets during the past 25 years.

METHODS

Data on five cohorts were collected in 1995 (n = 498), 1998 (n = 796), 2003 (n = 2383), 2010 (n = 1383), and 2020 (n = 719). The 20mSRT was administered, following the exact same protocol, to all cohorts. A general linear contrast model was used to examine cohort differences in the 20mSRT scores. Variation across cohorts was tested using chi-square-based between-group tests.

RESULTS

Girls' 20mSRT scores decreased from 1995 to 2010 and remained stable from 2010 to 2020. Boys' 20mSRT scores decreased continuously from 1995 to 2020. In addition, the variation in girls' 20mSRT scores was larger in the 2020 than 2003 cohort, indicating the growth of SRT differences between individuals in 2020 cohort compared to 2003 cohort. Similarly, boys' scores showed greater variation, especially in the 2010 and 2020 cohorts than in the 1998 cohort.

CONCLUSION

The results of this study showed an overall decline in the cardiorespiratory fitness performance measured by 20mSRT of Finnish adolescents. Boys' scores decreased continuously from 1995 to 2020, whereas girls' scores remained stable after 2010. Examination of the variation in scores further revealed that the gap in scores between the adolescents with the highest and lowest scores increased over time.

Changes in the continuous leaping performance of Finnish adolescents between 1979 and 2020

The aims of this secular trend design study were: 1) to investigate whether the continuous leaping performance of Finnish adolescents (mean age 14.99 ± .61 years) changed between 6 data sets collected between 1979 and 2020, and 2) to analyse if variation in leaping performance increased from 1979 to 2020. The data for this secular trend study of 6 cohorts were collected in 1979 (n = 599), 1995 (n = 498), 1998 (n = 796), 2003 (n = 2383), 2010 (n = 1383), and 2020 (n = 719). All cohorts performed the 5-leaps test, following the same protocol. Between-cohort differences in scores were analysed using a General Linear Contrast Model. Between-cohort differences in variance were tested using Chi-square-based between-group tests. Sex, age, and BMI were used as covariates in the secular trend analyses. Continuous leaping performance demonstrated a decreasing trend in both girls and boys. Specifically, girls' scores were stable between 1979 and 1995, decreased from 1995 to 2010 and remained stable thereafter. Boys leaping performance improved from 1979 to 1995, was stable until 2003, and had declined by 2020. Within-group variation in continuous leaping was greater in girls and boys during the first decades of the 21st century than previously.

Secular trends in physical fitness of Slovenian boys and girls aged 7 to 15 years from 1989 to 2019: a population-based study

Using the population-based data we aim to estimate the general population trends of multiple components of physical fitness of children, identify critical structural changes in these trends, and evaluate the potential changes in differences in the test scores between the children. During the entire study period, 1989-2019, median body mass index and triceps skinfold increased in both genders and all age groups. Muscular fitness, in general, showed negative trends, with some exceptions: during the post-2010 period, children were mostly experiencing the improvement of isometric strength of the upper body. The neuromuscular components of physical fitness showed positive trends, especially in girls. Cardiorespiratory fitness has been declining in all age groups until the last decade, with the largest decreases occurring before 2000. In the last decade, the trends reversed. The flexibility indicator revealed the largest differences between boys and girls, with boys mainly experiencing negative and girls mostly positive trends. The variability of the test scores mostly increased during the study period. This increasing variance suggests that-despite generally favourable trends in the last decade-children in Slovenia have been facing increasing inequalities in their development, which can potentially lead to future inequalities in health.

Changes in the adiposity level and prevalence of overweight/obesity among children from Kraków (Poland) within the last decade (from 2010 to 2020)

The aim of this study was to assess the changes in the prevalence of overweight, obesity and high adiposity in children and adolescents from Krakow (Poland), between the years 2010 and 2020. Two cross-sectional series of anthropometric measurements were carried out in 2010 and 2020. Analysed characteristics included: body height and weight, BMI (Body Mass Index), body adiposity (%BF). The subjects were categorised according to their BMI (underweight, normal weight, overweight, obesity), as well as %BF (low, normal, high body fat).The research was conducted in randomly selected primary schools in Krakow (Poland). Studied cohorts (8-15 years of age), which represented four of the traditional residential districts: Śródmieście, Podgórze, Krowodrza and Nowa Huta. Among the girls, there was a negative secular trend regarding the prevalence of underweight and obesity. On the other hand, there also was a positive trend concerning the prevalence of overweight and low and high body fat. In boys, there was a negative secular trend regarding the prevalence of underweight and low adiposity. There was also a generally positive secular trend regarding the prevalence of overweight, obesity as well as high adiposity in boys. The findings of this study are particularly significant because detailed knowledge of the prevalence of overweight/obesity in childhood and adolescence is crucial for the future health of entire populations. Further studies should also take into account the levels of physical fitness and activity of the examined population.

Three-Year Intervention Effects on Food and Beverage Intake-Results from the Quasi-Experimental Copenhagen School Child Intervention Study (CoSCIS)

The diet of Danish children is often not in accordance with dietary guidelines. We aimed to evaluate changes in the intake of selected foods and beverages during a multi-component school-based physical activity intervention, and to investigate if changes were modified by socioeconomic status (SES). The study included 307 children (intervention group: 184; comparison group: 123) with information on dietary intake pre- and post-intervention as well as on SES. Linear regression models were conducted to assess the effect of the intervention on changes in dietary factors. Children from the intervention group increased their intake of whole-grain bread during the intervention (group means: 6.1 g/d (95% CI: 2.2 to 10.0) vs. 0.3 g/d (95% CI: −3.1 to 3.7) in the comparison group, p = 0.04). A significant interaction between SES and group allocation was observed to change in fruit intake (p = 0.01). Among children from low SES families, only those from the comparison group decreased their fruit intake (group means: −40.0 g/d (95% CI: −56.0 to −23.9) vs. 9.3 g/d (95% CI: −16.1 to 94) in the intervention group, p = 0.006). The present study found no convincing effect of introducing a multi-component intervention on dietary intake except a small beneficial effect on whole-grain bread consumption. However, beneficial intervention effects in fruit intake were found particularly among children from low SES families.

Secular trends in health-related physical fitness among 11-14-year-old Croatian children and adolescents from 1999 to 2014

The main purpose of the study was to analyze secular trends of health-related physical fitness in 7–14-year-old Croatian children and adolescents from 1999 and 2014. In this observational cross-sectional study, we recruited 5077 children and adolescents between ages 11 and 14 (50.8% girls) from five primary schools located in the capital city of Zagreb. Physical fitness performance was tested from 1999 until 2014. Physical fitness performance included: (1) body-mass index (measure of body size), (2) standing broad jump (measure of lower-body power), (3) polygon backwards (measure of general coordination and agility), (4) sit-ups in 60 s (measure of upper-body strength), (5) sit-and-reach test (measure of flexibility) and (6) 6-min run test (measure of cardiorespiratory fitness). Boys performed better in all physical fitness tests, except for sit-and-reach test (p < 0.001). In boys, between 1999 and 2014, body size, upper-body strength and coordination/agility increased, while flexibility, lower-body power and cardiorespiratory fitness decreased. During the same period, girls experienced an increase in body size, lower-body power, upper-body strength, coordination/agility and flexibility, while cardiorespiratory fitness decreased. This study shows that cardiorespiratory fitness, flexibility and coordination/agility decrease, while upper-body strength increases in both sexes. These findings should serve as an avenue for national monitoring system to screen and track biological development in children and adolescents.

Fitness Level Differences between Students in Kosovo and Montenegro

Geographical, cultural, and socio-economic factors create a different lifestyle. Accordingly, the aim of this research was to identify the differences in anthropometric and fitness characteristics among adolescents living in Montenegro and Kosovo in order to optimize the physical fitness as a consequence of the proactive behavior. Anthropometric characteristics and fitness level measures were assessed by Eurofit testing battery among 600 Kosovar and 600 Montenegrin students, equally distributed by gender. Differences between countries, gender, and age group (13, 14 and 15 years) were assessed with multivariate and univariate analysis of variance. The results showed that Montenegrin students are taller, heavier, and achieve better results in the sit-ups and 20-m endurance shuttle-run tests. Kosovar students achieve better results in the standing broad jump and 10 × 5 m shuttle-run tests. Males achieve significantly better results in all tests, excluding the sit-and-reach test. Statistically significant differences among age groups were found for all variables, regardless gender and country (except for the flamingo and sit-and reach tests). This study is of importance to physical education teachers and curriculum authors to optimize students’ proactive behavior based on the identified anthropometric and physical fitness differences between the two countries, age groups, and genders.

An Update on Secular Trends in Physical Fitness of Children and Adolescents from 1972 to 2015: A Systematic Review

BACKGROUND

There is evidence that physical fitness of children and adolescents (particularly cardiorespiratory endurance) has declined globally over the past decades. Ever since the first reports on negative trends in physical fitness, efforts have been undertaken by for instance the World Health Organization (WHO) to promote physical activity and fitness in children and adolescents. Therefore, it is timely to re-analyze the literature to examine whether previous reports on secular declines in physical fitness are still detectable or whether they need to be updated.

OBJECTIVES

The objective of this systematic review is to provide an 'update' on secular trends in selected components of physical fitness (i.e., cardiorespiratory endurance, relative muscle strength, proxies of muscle power, speed) in children and adolescents aged 6-18 years.

DATA SOURCES

A systematic computerized literature search was conducted in the electronic databases PubMed and Web of Science to locate studies that explicitly reported secular trends in physical fitness of children and adolescents.

STUDY ELIGIBILITY CRITERIA

Studies were included in this systematic review if they examined secular trends between at least two time points across a minimum of 5 years. In addition, they had to document secular trends in any measure of cardiorespiratory endurance, relative muscle strength, proxies of muscle power or speed in apparently healthy children and adolescents aged 6-18 years.

STUDY APPRAISAL AND SYNTHESIS METHODS

The included studies were coded for the following criteria: nation, physical fitness component (cardiorespiratory endurance, relative muscle strength, proxies of muscle power, speed), chronological age, sex (boys vs. girls), and year of assessment. Scores were standardized (i.e., converted to z scores) with sample-weighted means and standard deviations, pooled across sex and year of assessment within cells defined by study, test, and children's age.

RESULTS

The original search identified 524 hits. In the end, 22 studies met the inclusion criteria for review. The observation period was between 1972 and 2015. Fifteen of the 22 studies used tests for cardiorespiratory endurance, eight for relative muscle strength, eleven for proxies of muscle power, and eight for speed. Measures of cardiorespiratory endurance exhibited a large initial increase and an equally large subsequent decrease, but the decrease appears to have reached a floor for all children between 2010 and 2015. Measures of relative muscle strength showed a general trend towards a small increase. Measures of proxies of muscle power indicated an overall small negative quadratic trend. For measures of speed, a small-to-medium increase was observed in recent years.

LIMITATIONS

Biological maturity was not considered in the analysis because biological maturity was not reported in most included studies.

CONCLUSIONS

Negative secular trends were particularly found for cardiorespiratory endurance between 1986 and 2010-12, irrespective of sex. Relative muscle strength and speed showed small increases while proxies of muscle power declined. Although the negative trend in cardiorespiratory endurance appears to have reached a floor in recent years, because of its association with markers of health, we recommend further initiatives in PA and fitness promotion for children and adolescents. More specifically, public health efforts should focus on exercise that increases cardiorespiratory endurance to prevent adverse health effects (i.e., overweight and obesity) and muscle strength to lay a foundation for motor skill learning.

Secular Trends of Physical Fitness in Twenty-Five Birth Cohorts of Slovenian Children: A Population-Based Study

In Slovenia, the national SLOfit surveillance system of the somatic and motor development of children and youth has been enabling researchers to observe the developmental trends of the entire population of school-aged children since 1987. The national database currently incorporates over 7.2 million sets of measurements of eight fitness tests and three anthropometric measurements. Since 1991, as in the rest of the world, in Slovenia, there is a common perception that the physical fitness of contemporary children is in decline and below the level of the physical fitness of the previous generation's childhood fitness. Our paper examines the trends of physical fitness in 26 birth cohorts of 7–10-year-olds. The analysis shows that the secular trends of physical fitness in boys and especially in girls have been positive and that the level of physical fitness of recent birth cohorts exceeds the national average of physical fitness of the 1989–2019 period. At the same time, the analysis reveals that the distribution of physical fitness has been changing from almost normal in the cohorts born in the first half of the 1980s, toward positively skewed in the subsequent cohorts born before the year 2000, and bimodal distribution in the later cohorts, indicating growing inequality and polarization of the motor development of children.

The Mediating Effect of Pupils' Physical Fitness on the Relationship Between Family Socioeconomic Status and Academic Achievement in a Danish School Cohort

INTRODUCTION

Family socioeconomic status influences pupils' academic achievements, and studies have established positive associations between physical fitness and academic achievements. However, whether physical fitness mediates the relationship remains unknown.

OBJECTIVE

We investigated if pupils' physical fitness mediates the pathway between family socioeconomic status and academic achievement using causal inference-based mediation analysis.

METHODS

This study included 527 girls and 552 boys between 13 and 15 years of age from the Danish municipality of Aalborg. Physical fitness was measured through VO₂max tests in 2010 and demographic data were obtained from nationwide registers. Family socioeconomic status was classified into four levels ranging from 1 to 4, where level 1 represents the lowest and level 4 the highest based on either family income or education.

RESULTS

Controlling for sex, ethnicity, age, and parents' cohabitation status, all total effects display higher academic achievement with increased family socioeconomic status. Splitting the effects, the direct effects reveal the existence of other pathways not involving physical fitness. The indirect effects established physical fitness as a mediator showing that pupils from family socioeconomic status levels one, three, and four changes grade by - 0.13 [95% confidence interval (CI) - 0.26, - 0.01], 0.07 (95% CI 0.00, 0.14), and 0.24 (95% CI 0.14, 0.34), respectively, compared to socioeconomic status level two. The corresponding proportions mediated are 18% (95% CI 1, 57), 6% (95 CI 0, 13), and 12% (95% CI 7, 18) when family socioeconomic status is based on education. Classifying family socioeconomic status on income, pupils from family socioeconomic status levels one, three, and four show grade changes of - 0.07 (95% CI - 0.16, 0.02), 0.22 (95% CI 0.13, 0.32), and 0.26 (95% CI 0.15, 0.37), respectively, compared to socioeconomic status level two. The corresponding proportions mediated are 12% (95% CI - 6, 41), 30% (95% CI 16, 54), and 20% (95% CI 12, 32).

CONCLUSION

In conclusion, pupils' physical fitness partially mediated the pathway between family socioeconomic status and academic achievement.

Changes in the prevalence of overweight/obesity and adiposity among pre-school children in Kraków, Poland, from 2008 to 2018

Socioeconomic changes occurring over time influence the lifestyle choices of a population, and these can significantly affect children’s body weight and composition. The aim of this study was to assess the changes in prevalence of overweight, obesity and adiposity in pre-school children in Poland between 2008 and 2018. Body height, body weight and subscapular and triceps skinfolds were measured in 2167 children aged 3–7 years from Kraków. Body mass index and adiposity (percentage body fat, %BF) were calculated for the children, who were then categorized as underweight, normal weight, overweight or obese according to Cole’s cut-off points. Adiposity was categorized according to the z-scores for %BF as low (<−1), normal (−1 to 1) or high (>1). Differences between cohorts were analysed using the chi-squared test. Only the decrease in the prevalence of obesity in 5-year-old girls was found to be statistically significant. However, some overall tendencies were noted. Decreases in the prevalence of underweight, overweight and obesity were observed for both sexes, as well as in the incidence of high adiposity in boys and low adiposity in girls. Increases in the prevalence of high adiposity in girls and low adiposity in boys were also noted. There was no significant change in the prevalence of overweight and obesity among pre-school children over the study decade, and the visible tendencies included decreases in the prevalence of excess body weight and adiposity as well as underweight and low body fat. Also, the visible trends in adiposity were mostly negative. Further studies should, however, also consider the levels of physical fitness and activity of children, as these have a crucial influence on the measured characteristics.

A Cross-Sectional Pilot Study to Examine the Criterion Validity of the Modified Shuttle Test-Paeds as a Measure of Cardiorespiratory Fitness in Children

With accumulating evidence that exercise capacity decreases all-cause mortality independent of adiposity, benefits may be gained by developing cardiorespiratory fitness measures that are specifically and sensitively designed for use with pediatric populations when cardiorespiratory fitness may be a contributing factor for obesity. This study aimed to examine the criterion validity of the Modified Shuttle Test-Paeds (MSTP) as a measure of cardiorespiratory fitness in children, against the gold-standard reference; VO₂peak, compared to the commonly used field-test; 20-m Multi-Stage-Shuttle-Run-Test (20-m MSRT). A cross-sectional pilot study, with 25 school-aged children (age: 6–16 year; male/female: 19/5; BMI: 21 ± 9 kg/m²) was employed. Physical measures included: Bruininks-Oseretsky-Test-of-Motor-Proficiency-2nd Edition (BOT2), VO₂peak, 20-m MSRT, MSTP, body composition/anthropometry. The mean cardiorespiratory fitness of participants was: VO₂peak: 43.8 ± 11.2 (mL/kg/min); 20-m MSRT: 5.48 ± 2.96 (level); MSTP: 22.10 ± 3.05 (no.). A strong predictive relationship was found between the 20-m MSRT and VO₂peak (r² = 0.486, p < 0.001) whereas a very strong predictive relationship existed between the newly designed MSTP and VO₂peak (r² = 0.749, p < 0.001). Whilst further research with larger study cohorts is needed, this pilot study found the MSTP to have a very high predictive validity for estimating VO₂peak in children, suggesting it may be a valid child-specific indicator of cardiorespiratory fitness requiring only a simple equation that is clinically relevant.

The indirect and direct pathways between physical fitness and academic achievement on commencement in post-compulsory education in a historical cohort of Danish school youth

Background

Some studies have found positive associations between physical fitness and academic achievements. Pupils’ academic achievements should indicate scholastic abilities to commence a post-compulsory education. However, the effect magnitude of physical fitness and academic achievements on commencement in post-compulsory education is unknown. We examined the pathways between physical fitness and academic achievement on pupils’ commencement in post-compulsory education.

Methods

This historical cohort study followed 530 girls and 554 boys from the Danish municipality of Aalborg in the period 2008–2014, 13 to 15 years old in 2010. Physical fitness was assessed through a watt-max cycle ergometer test represented as VO₂max (mL·kg⁻¹·min⁻¹). Academic achievement, commencement status and information on covariates were obtained from Danish nationwide registers. Causal inference based mediation analysis was used to investigate the indirect and direct pathways by separating the total effect of physical fitness on post-compulsory education commencement.

Results

Adjusting for sex, age, ethnicity and socioeconomic status, the overall mediation analysis showed an odds ratio (OR) of 1.87 (95% confidence interval (CI): 1.30; 2.73) for the total effect, corresponding to an increase in odds of post-compulsory education commencement when the physical fitness was increased by 10 units of VO₂max. The separated total effect showed a natural direct OR of 1.36 (95% CI: 0.93; 1.98) and a natural indirect (i.e., through academic achievement) OR of 1.37 (95% CI: 1.20; 1.57). Thus, 51% (95% CI: 27%; 122%) of the effect of physical fitness on post-compulsory education commencement was mediated through academic achievement.

Conclusion

Physical fitness had a positive effect on post-compulsory education commencement. A substantial part of this effect was mediated through academic achievement.

Association Between Physical Fitness and Academic Achievement in a Cohort of Danish School Pupils

BACKGROUND

Time spent on physical activity in elementary school has been altered to improve core academics. However, little is known about the relationship between physical fitness and academic achievement. We examined the association between physical fitness and academic achievement and investigated the influence of parental socioeconomic status and ethnicity.

METHODS

Participants were 542 girls and 577 boys aged 13 to 15 residing in the Danish municipality of Aalborg. A watt-max cycle ergometer test was completed to evaluate physical fitness as represented by VO2 max (mL·kg(-1) ·min(-1) ). Academic achievement was measured 1 school year later through a series of mandatory exams within the humanities, sciences, and all obligatory defined exams. Parental income and education were drawn from nationwide registers. Linear regression models were used to investigate the association.

RESULTS

Adjusting for ethnicity and parental socioeconomic status, the effect size of the humanities was 0.08 grad/VO2 max (95% Cl: 0.05 to 0.11) for girls and 0.06 grad/VO2 max (95% Cl:0.03 to 0.08) for boys. The effect size of the sciences was 0.09 grad/VO2 max (95% Cl:0.05 to 0.13) for girls and 0.06 grad/VO2 max (95% Cl:0.03 to 0.09) for boys. The effect size of the defined exams was 0.09 grad/VO2 max (95% Cl:0.06 to 0.11) for girls and 0.06 grad/VO2 max (95% Cl:0.03 to 0.08) for boys.

CONCLUSION

We found a statistically significant positive association between physical fitness and academic achievement after adjusting for ethnicity and parental socioeconomic status.

Association between health-related physical fitness and body mass index status in children

The purpose of this study was to investigate the association between body mass index (BMI) status and physical performance in Brazilian children. The analyzed sample was composed of 978 children of both sexes (518 boys and 460 girls), aged 7 to 11 years. BMI and skinfolds were measured, and three motor tests were applied (flexibility, cardiorespiratory fitness, and muscular strength/endurance). In both sexes, overweight/obese children presented poor performance in all motor tests, except flexibility. In general, overweight/obese children have an increased odds ratio (OR) to present poor physical performance (boys: OR = 3.64 for cardiorespiratory fitness, OR = 1.94 for muscular strength/endurance, OR = 1.52 for flexibility; girls: OR = 5.03 for cardiorespiratory fitness and OR = 2.62 for muscular strength/endurance). In conclusion, for both sexes, a poor physical performance in the tests measuring cardiorespiratory fitness and muscular strength/ endurance was associated with the presence of overweight/obesity.

The relationship between children's motor proficiency and health-related fitness

AIMS

The overall purpose of this study was to examine the relationship between motor proficiency and health-related fitness in children. In addition, the study aimed to determine if particular combinations of motor skills have a stronger relationship with individual health-related fitness measures.

METHODS

Seventy-seven children (F:28, M:49) (mean age: 11.19 ± 2.74 years) participated in this prospective cohort study. Physical measures included the following: motor proficiency (Bruininks-Oseretsky Test of Motor Proficiency, Second Edition), body mass index (BMI), waist circumference, blood pressure, heart rate and VO(2) peak (mL/kg/min).

RESULTS

After factoring in age, motor proficiency as a combined total score had a strong negative relationship with the health-related fitness measures of BMI (r (2)  = 0.62, P < 0.001) and waist circumference (r (2)  = 0.72, P < 0.001) and a strong positive relationship with VO2 peak (r (2)  = 0.78, P = 0.002). Children with lower motor proficiency (≤25th percentile) had a significantly larger mean waist circumference (M = 13.85 cm, 95% confidence interval (CI) (2.05, 25.66), P = 0.01), heavier weight (M = 22.17 kg, 95% CI (2.44, 41.91), P = 0.02) and higher BMI (M = 5.10 kg/m(2) , 95% CI (0.33, 9.87), P = 0.03) than children with higher motor proficiency (≤75th percentile).

CONCLUSIONS

Motor proficiency, once corrected for age, is significantly related to a number of health-related measures in children and should therefore be considered a focus for investigation for children with poor health-related fitness (e.g. high BMI and waist circumference percentiles or low cardiorespiratory fitness), as motor incompetence could be an underlying contributing factor to a child's poor physical health.

Importance of physical health and health-behaviors in adolescence for risk of dropout from secondary education in young adulthood: an 8-year prospective study

BACKGROUND

Education and health constitute two interlinked assets that are highly important to individuals. In Iceland, prevalence of dropout from secondary education poses a considerable problem. This 8-year prospective study assesses to what extent poor physical health and negative health-behaviors of Icelandic adolescents predict increased odds of dropout from secondary education.

METHODS

The sample included n = 201 Icelandic children who participated at age 15 (baseline) and again at age 23 (follow-up). Data included objective measurements of physical health and questionnaires assessing health-behaviors, education status, parental education, neighborhood characteristics, self-esteem, and depression. Independent t-tests and chi-square were used to assess differences in physical health and health-behaviors at follow-up stratified by education status. Ordinal regression models were conducted to assess whether physical health and health-behaviors at age 15 predicted increased odds of dropout from secondary education at age 23, independent of gender, parental education and psychological factors.

RESULTS

At age 23, 78 % of girls and 71 % of boys had completed a secondary education. Completion of a secondary education was associated with significant health benefits, especially among women. Women without a secondary education had lower fitness, more somatic complaints, higher diastolic blood pressure, less sports participation, and poorer sleep, whilst men without a secondary education watched more television. In logistic regression models somatic complaints during adolescence were associated with 1.09 (95 % CI: 1.02-1.18) higher odds of dropout from secondary education in young adulthood, independent of covariates. Health-behaviors associated with higher dropout odds included smoking (3.67, 95 % CI: 1.50-9.00), alcohol drinking (2.57, 95 % CI: 1.15-5.75), and time spent watching television (1.27, 95 % CI:1.03-1.56), which were independent of most covariates. Finally, mother's higher education was strongly associated with significantly lower dropout odds (OR 0.54, 95 % CI: 0.34-0.88) independent of father's education and psychological factors, whilst high self-esteem was independently associated with lower dropout odds (OR 0.91, 95 % CI: 0.85-0.98).

CONCLUSIONS

Completion of a secondary education yields substantial physical health benefits for young women, but not for men. Importantly, somatic complaints and negative health-behaviors among adolescent boys and girls adversely impact their educational outcomes later in life, and may have widespread consequences for their future prospects.

The association between weight perception and BMI: report and measurement data from the growing up in Ireland Cohort Study of 9-year olds

BACKGROUND

The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies.

OBJECTIVES

To determine if a child's weight perception or a mother's perception of a child's weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother's BMI on her ability to categorise the child's BMI and a child's ability to recognise his/her own BMI.

METHODS

Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child's gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother's weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen's weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables.

RESULTS

Mothers are more accurate at correctly classifying their child's BMI (κ=0.5; confidence intervals (CI) 0.38-0.51) than the children themselves (κ=0.25; CI 0.23-0.26). Overweight mothers are better raters of their child's BMI (κ=0.51; CI 0.49-0.54), compared with normal (κ=0.44; CI 0.41-0.47) or underweight mothers (κ=0.4; CI 0.22-0.58), regardless of whether the mother's BMI is derived from measured height and weight or self-perceived. The mother's perception of the child's weight status is not an influencing factor on the child's ability to correctly classify him/herself, but the child's self-perceived weight status influences the mother's ability to correctly classify the child.

CONCLUSIONS

A mother's BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.

What do Danish children eat, and does the diet meet the recommendations? Baseline data from the OPUS School Meal Study

A child's diet is an important determinant for later health, growth and development. In Denmark, most children in primary school bring their own packed lunch from home and attend an after-school care institution. The aim of the present study was to evaluate the food, energy and nutrient intake of Danish school children in relation to dietary guidelines and nutrient recommendations, and to assess the food intake during and outside school hours. In total, 834 children from nine public schools located in the eastern part of Denmark were included in this cross-sectional study and 798 children (95·7 %) completed the dietary assessment sufficiently (August–November 2011). The whole diet was recorded during seven consecutive days using the Web-based Dietary Assessment Software for Children (WebDASC). Compared with the food-based dietary guidelines and nutrient recommendations, 85 % of the children consumed excess amounts of red meat, 89 % consumed too much saturated fat, and 56 % consumed too much added sugar. Additionally 35 or 91 % of the children (depending on age group) consumed insufficient amounts of fruits and vegetables, 85 % consumed insufficient amounts of fish, 86 % consumed insufficient amounts of dietary fibre, 60 or 84 % had an insufficient Fe intake (depending on age group), and 96 % had an insufficient vitamin D intake. The study also showed that there is a higher intake of fruits and bread during school hours than outside school hours; this is not the case with, for example, fish and vegetables, and future studies should investigate strategies to increase fish and vegetable intake during school hours.

Health-related fitness profiles in adolescents with complex congenital heart disease

PURPOSE

This study investigates whether subgroups of different health-related fitness (HrF) profiles exist among girls and boys with complex congenital heart disease (ConHD) and how these are associated with lifestyle behaviors.

METHODS

We measured the cardiorespiratory fitness, muscle strength, and body composition of 158 adolescents aged 13-16 years with previous surgery for a complex ConHD. Data on lifestyle behaviors were collected concomitantly between October 2010 and April 2013. A cluster analysis was conducted to identify profiles with similar HrF. For comparisons between clusters, multivariate analyses of covariance were used to test the differences in lifestyle behaviors.

RESULTS

Three distinct profiles were formed: (1) Robust (43, 27%; 20 girls and 23 boys); (2) Moderately Robust (85, 54%; 37 girls and 48 boys); and (3) Less robust (30, 19%; 9 girls and 21 boys). The participants in the Robust clusters reported leading a physically active lifestyle and participants in the Less robust cluster reported leading a sedentary lifestyle. Diagnoses were evenly distributed between clusters.

CONCLUSIONS

The cluster analysis attributed some of the variability in cardiorespiratory fitness among adolescents with complex ConHD to lifestyle behaviors and physical activity. Profiling of HrF offers a valuable new option in the management of person-centered health promotion.

The influence of anthropometry and body composition on children's bone health: the childhood health, activity and motor performance school (the CHAMPS) study, Denmark

Overweight, physical inactivity and sedentary behaviour have become increasing problems during the past decade. Increased sedentary behaviour may change the body composition (BC) by increasing the fat mass relative to the lean mass (LM). These changes may influence bone health to describe how anthropometry and BC predict the development of the bone accruement. The longitudinal study is a part of The CHAMPS study-DK. Children were DXA scanned at baseline and at 2-year follow-up. BC (LM, BF %) and BMC, BMD and BA were measured. The relationship between bone traits, anthropometry and BC was analysed by multilevel regression analyses. Of the invited children, 742/800 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow-up. Mean (range) of age at baseline was 9.5 years (7.7-12.1). Height, BMI, LM and BF % predicted bone mineral accrual and bone size positively and independently. Height and BMI are both positive predictors of bone accruement. LM is a more precise predictor of bone traits than BF % in both genders. The effects of height and BMI and LM on bone accruement are nearly identical in the two genders, while changes in BF % have different but positive effects on bone accretion in both boys and girls.

Result of school-based intervention on cardiovascular risk factors

OBJECTIVE

To assess the effectiveness of a two-year school-based intervention, consisting of integrated and replicable physical activity and nutritional education on weight, fat percentage, cardiovascular risk factors, and blood pressure.

DESIGN AND SETTING

Six elementary schools in Reykjavik were randomly assigned to be either intervention (n = 3) or control (n = 3) schools. Seven-year-old children in the second grade in these schools were invited to participate (n = 321); 268 (83%) underwent some or all of the measurements. These 286 children were followed up for two years.

INTERVENTION

Children in intervention schools participated in an integrated and replicable physical activity programme, increasing to approximately 60 minutes of physical activity during school in the second year of intervention. Furthermore, they received special information about nutrition, and parents, teachers, and school food service staff were all involved in the intervention. Subjects. 321seven-year-old schoolchildren.

MAIN OUTCOME MEASURES

Blood pressure, obesity, percentage of body fat, lipid profile, fasting insulin.

RESULTS

Children in the intervention group had a 2.3 mmHg increase in systolic blood pressure (SBP) and a 2.9 mmHg increase in diastolic blood pressure (DBP) over the two-year intervention period, while children in the control group increased SBP by 6.7 mmHg and DPB by 8.4 mmHg. These changes were not statistically significant. Furthermore there were no significant changes in percentage body fat, lipid profile, or fasting insulin between the intervention and control schools.

CONCLUSION

A two-year school-based intervention with increased physical activity and healthy diet did not have a significant effect on common cardiovascular risk factors.

School day and weekend patterns of physical activity in urban 11-year-olds: a cross-cultural comparison

OBJECTIVES

This multi-center study was conducted to objectively evaluate energy expenditure and physical activity (PA) patterns on school days and weekends in urban 11-year-olds.

METHODS

The sample consisted of 241 children from three cities: Zagreb, Ljubljana (both in Central Europe) and Ann Arbor (United States). Energy expenditure and PA were assessed during two school days and two weekend days using a multiple-sensor body monitor.

RESULTS

Differences between the cities were observed for all PA variables. The highest level of moderate to vigorous PA (MVPA) was noted in Ljubljana boys [284 (98) min/day] and the lowest in Zagreb girls [179 (95) min/day]. In Zagreb and Ljubljana, boys were more physically active than girls, while in Ann Arbor the opposite was observed. In contrast, no gender difference in sedentary behavior was observed in any of the cities. A decline in PA from school days to weekends was noted in all city groups in both genders. However, the magnitude of the reduction in daily energy expenditure differed between the cities, with the largest differences being observed in Ljubljana and the smallest in Ann Arbor. In all three city groups, the great majority of boys and girls achieved current recommendations of 60 min of MVPA either during school days or weekends.

CONCLUSIONS

Weekends seem to be an appropriate target when promoting PA in 11-year-olds in all the cities included in the study. Increasing vigorous activity on weekends seems to be of particular importance in Zagreb and Ljubljana.

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 6^th and 7^th 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 6^th and 7^th grade students.

Trial registration

Clinicaltrials.gov: NCT02012881 (10/10/2013)

Body fat throughout childhood in 2647 healthy Danish children: agreement of BMI, waist circumference, skinfolds with dual X-ray absorptiometry

BACKGROUND/OBJECTIVES

Total body fat percentage (%BF) evaluated by dual energy X-ray absorptiometry (DXA) scans (DXA %BF) is widely recognized as a precise measure of fatness. We aimed to establish national reference curves for DXA %BF, %BF calculated from skinfolds (SF %BF) and waist circumference (WC) in healthy children, and to compare agreement between the different methods.

SUBJECTS/METHODS

Based on 11 481 physical examinations (anthropometry) and 1200 DXA scans from a longitudinal cohort of Danish children (n=2647), we established reference curves (LMS-method) for SF %BF, WC (birth to 14 years) and DXA %BF (8-14 years). Age- and sex-specific Z-scores for body mass index (BMI), WC and SF %BF were compared. Sensitivity and specificity were calculated for agreement of WC, SF %BF and BMI with DXA %BF to identify obese children (>+1 s.d.).

RESULTS

%BF differed with age, sex, pubertal stage and social class. SF %BF correlated strongly with DXA %BF (r=0.86). BMI and WC also correlated positively with DXA %BF (Z-scores; r= 0.78 and 0.69). Sensitivity and specificity were 79.5 and 93.8 for SF %BF, 75.9 and 90.3 for BMI and 59.2 and 95.4 for WC.

CONCLUSIONS

SF %BF showed the highest correlation and best agreement with DXA %BF in identifying children with excess fat (+1 s.d.).

Trends in resting pulse rates in 9-11-year-old children in the UK 1980-2008

OBJECTIVE

Little is known about whether levels of physical fitness, which is related to adiposity and physical activity (PA), have changed in children, particularly the progressive increase in childhood obesity levels. We aimed to examine the time trends in resting pulse rate (a marker of physical fitness) among UK children, in order to better understand the trends in levels of physical fitness in recent decades.

DESIGN AND SETTING

We used a cross-sectional study design and included data on over 22 000 children aged 9-11 years (mean 10.3 years) from five population-based studies conducted in the UK between 1980 and 2008.

MAIN OUTCOME MEASURES

Resting pulse rate (bpm).

RESULTS

Observed mean resting pulse rate was higher for girls than boys (82.2 bpm vs 78.7 bpm). During the study period mean pulse rate increased by 0.07 bpm/year (95% CI 0.04 to 0.09) among boys and to a lesser extent among girls, by 0.04 bpm/year (0.01 to 0.06) (p<0.05 for gender interaction). For boys, there was an indication that the trend was steeper after the mid-1990 s, compared to that prior to 1994 (annual increase 0.14 vs 0.04 bpm). The trends for Body Mass Index (BMI) accounted for only 13.8% (11.3% to 16.3%) of increase in pulse rate for boys and 17.2% (9.4% to 24.9%) for girls.

CONCLUSIONS

Increases in mean resting pulse rate have occurred during the period 1980-2008 in girls and especially in boys. The increase was not explained by increased BMI. The observed trends in children, though modest, could have important public health implications for future cardiovascular risk.

Comparison of effect of regular unstructured physical training and athletic level training on body composition and cardio respiratory fitness in adolescents

BACKGROUND

Childhood obesity and hypertension are global problems that are on the rise in India. Improving physical activity is an accepted main line of strategy for overcoming poor body composition, hypertension and reduced cardio respiratory fitness (CRF) all of which are considered as independent risk factors for the development of future cardiovascular complications.

AIM

Present study was conducted to evaluate the effect of regular unstructured physical training and athletic level training on anthropometric measures, body composition, blood pressure and cardio respiratory fitness in adolescents.

SETTINGS AND DESIGN

This is a collaborative study between the Department of physiology, Jawaharlal Institute of Postgraduate Medical Education and Research and Residential school, Jawahar Navodhya Vidyalaya, Puducherry, India.

METHOD AND MATERIAL

Student volunteers in the age group of 12-17 years were classified into athletes (group 1) and physically active non-athletes (group 2). Parameters measured and calculated were weight, height, body mass index, waist and hip circumference, body fat percentage (BF%), fat free mass (FFM), Systolic (SBP) & Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Rate pressure product (RPP) and Predicted VO2 max.

STATISTICAL ANALYSIS USED

Mean difference between the groups was analysed using unpaired Student's t-test. All statistical analysis was carried out for two-tailed significance at the 5 % level using SPSS version 19 (SPSSInc, USA).

RESULTS

Anthropometric measures, body composition measures and blood pressure values of both the group students were within the normal limits. There was no significant difference in anthropometric and body composition parameters between the group 1 and group 2 students. DBP, MAP and RPP were significantly lower in group 1 students when compared to group 2 students. VO2 max values were more in group 1 girls as compared to group 2 girls while the values of boys were comparable between the two groups.

CONCLUSION

Regular unstructured physical activity for 60 minutes daily for the duration of one year can help the students to maintain their anthropometric parameters, body composition measures and CRF at par with the athletes of the same age and gender. However, athletic level training further reduces the cardiovascular load of the adolescent students.

Ethnic differences in leptin and adiponectin levels between Greenlandic Inuit and Danish children

Objective

In a recent study, we found that Greenlandic Inuit children had a more adverse metabolic profile than Danish children. Aerobic fitness and adiposity could only partly account for the differences. Therefore, we set out to evaluate and compare plasma leptin and adiponectin levels in Danish and Inuit children.

Methods

In total, 187 Inuit and 132 Danish children (5.7–17.1 years) had examinations of anthropometrics, body fat content, pubertal staging, fasting blood and aerobic fitness.

Results

Plasma leptin was higher in Danish boys [3,774 (4,741–3,005)] [pg/mL unadjusted geometric mean (95% CI)] compared to both northern [2,076 (2,525–1,706)] (p<0.001) and southern (2,515 (3,137–2,016)) (p<0.001) living Inuit boys and higher in Danish girls [6,988 (8,353–5,847)] compared to southern living Inuit girls [4,910 (6,370–3,785)] (p=0.021) and tended to be higher compared to northern living Inuit girls [5,131 (6,444–4,085)] (p=0.052). Plasma adiponectin was higher for both Danish boys [22,359 (2,573–19,428)] [ng/mL unadjusted geometric mean (95% CI)] and girls [26,609 (28,994–24,420)] compared to southern living Inuit boys [15,306 (18,406–12,728)] and girls [18,864 (22,640–15,717)] (both p<0.001), respectively. All differences remained after adjustment for body fat percentage (BF%), aerobic fitness, age and puberty. The leptin/adiponectin ratio was higher in Danish boys and tended to be higher in Danish girls compared to northern living Inuit boys and girls, respectively. These differences were eliminated after adjustment for BF%, aerobic fitness, age and puberty.

Conclusions

In contrast to our hypothesis, plasma leptin was higher in Danish children despite a more healthy metabolic profile compared to Inuit children. As expected, plasma adiponectin was lowest in Inuit children with the most adverse metabolic profile.

High cardiorespiratory fitness is inversely associated with incidence of overweight in adolescence: a longitudinal study

To assess the association of baseline cardiorespiratory fitness (CRF) with incidence of overweight over a 4.6-year period in adolescence. In a cohort of 4878 adolescents, we assessed body mass index in years 2001-2003 and 2007. CRF was assessed at baseline as maximal oxygen consumption (VO2max , mL/kg/min) using the 20-m shuttle run test and was examined against incidence of overweight at follow-up. Estimated VO2max at baseline was higher in males than in females, P < 0.001, and was lower in overweight and obese than in non-overweight subjects. The incidence of overweight at follow-up among non-overweight participants at baseline was 15.5% [95% confidence interval (CI) 13.7% to 17.3%] in males and 5.6% (95% CI 4.9% to 7.0%) in females, P < 0.001. Adjusted odds ratio for incidence of overweight in participants in the fourth quartile of VO2max was 0.40 (95%CI 0.26 to 0.61) in males and 0.57 (95% CI 0.33 to 0.99) in females in comparison with participants in the first quartiles of VO2max . Incidence of overweight was three times more frequent in males than in females. Among non-overweight at baseline, high fitness levels were inversely associated with incidence of overweight at follow-up, suggesting that interventions aiming to increase CRF in early childhood might help reverse increasing trends in obesity.

Trends of overweight and obesity, physical activity and sedentary behaviour in Czech schoolchildren: HBSC study

BACKGROUND

The decline of physical activity (PA) and the increased prevalence of overweight and obese children have been discussed worldwide. This study assessed the trends in the prevalence of overweight and obesity, PA and sedentary behaviour in Czech school-aged children.

METHODS

A cross-sectional questionnaire from the Czech Republic was administered in cycles in 2002, 2006 and 2010 under the Health Behaviour in School-Aged Children (HBSC) study. In the study, 14,219 children aged 11-15 years participated.

RESULTS

In comparison with 2002, there is a significant increase (P < 0.01) of obese and overweight boys in 2010. The same trend has been recorded in girls, except those in the 13-year-old group. There has been a significant decline (P < 0.05) in meeting PA recommendations in 11-year-old girls and boys and in 13-year-old girls when comparing the 2006 and 2002 data. In 2010, we found a non-significant increase or stagnation of the share of children meeting the PA recommendation compared with 2006. We found an increasing length of sedentary time for children. There were significant associations between>2 h being spent sitting by a TV or PC and consuming fruit and vegetables (negative associations) or sweets and sweetened lemonades (positive associations).

CONCLUSIONS

An increasing percentage of obese or overweight children, increased sedentary time and a decline or stagnation of the proportion of children meeting recommendations for PA were found among Czech schoolchildren. Future research should evaluate PA recommendations with respect to gender, age and effective intervention approach to reduce the obesity incidence in childhood.

Adverse metabolic risk profiles in Greenlandic Inuit children compared to Danish children

OBJECTIVE

During recent decades, the prevalence of metabolic morbidity has increased rapidly in adult Greenlandic Inuit. To what extent this is also reflected in the juvenile Inuit population is unknown. The objective was, therefore, in the comparison with Danish children, to evaluate metabolic profiles in Greenlandic Inuit children from the capital in the southern and from the northern most villages

DESIGN AND METHODS

187 Inuit and 132 Danish children were examined with anthropometrics, pubertal staging, fasting blood samples, and a maximal aerobic test.

RESULTS

Both Inuit children living in Nuuk and the northern villages had significantly higher glucose, total cholesterol, apolipoprotein A1 levels, and diastolic blood pressure compared with Danish children after adjustment for differences in adiposity and aerobic fitness levels. The Inuit children living in Nuuk had significantly higher BMI, body fat %, HbA1 c, and significantly lower aerobic fitness and ApoA1 levels than northern living Inuit children.

CONCLUSIONS

Greenlandic Inuit children had adverse metabolic health profile compared to the Danish children, the differences where more pronounced in Inuit children living in Nuuk. The tendencies toward higher prevalence of diabetes and metabolic morbidity in the adult Greenlandic Inuit population may also be present in the Inuit children population.

Children's aerobic fitness and academic achievement: a longitudinal examination of students during their fifth and seventh grade years

OBJECTIVES

We assessed children's potential differences in academic achievement based on aerobic fitness over a 2-year period.

METHODS

The longitudinal study sample included 3 cohorts of students (n = 1725; 50.1% male) enrolled in a West Virginia public school system. Students received baseline fitness and academic assessments as fifth graders and at a 2-year follow-up assessment. We used FitnessGram to assess fitness in aerobic capacity and WESTEST, a criterion-based assessment, for academic performance.

RESULTS

Students who stayed in the healthy fitness zone (HFZ) had significantly higher WESTEST scores than did students who stayed in the needs improvement zone (NIZ). Students who moved into or out of the HFZ occasionally had significantly higher WESTEST scores than did students who stayed in the NIZ, but they were rarely significantly lower than those of students who stayed in the HFZ.

CONCLUSIONS

Students' aerobic capacity is associated with greater academic achievement as defined by standardized test scores. This advantage appears to be maintained over time, especially if the student stays in the HFZ.

Physical fitness, weight, smoking, and exercise patterns in young adults

INTRODUCTION

The health and physical fitness of adolescents and young adults are important not just to the individuals concerned, but also to society as a whole. Many studies from many different countries have dealt with the prevalence of overweight, the risk factors for it, and the morbidity it causes, but no more than a few have addressed the effects of unhealthy lifestyles on physical fitness. In this study, we show that young adults' physical performance depends on the number of risk factors they possess. We also compare the young adults' physical performance with that of adolescents aged 10 to 17.

METHODS

We obtained cross-sectional data on the weight, smoking status, athletic activity, time to run 1 km, and ability to perform a chin-up on a horizontal bar of 8048 subjects aged 10 to 25. The young adults were divided into groups depending on the number of risk factors they possessed from the following list: overweight, smoking, and lack of exercise.

RESULTS

28.4% of the men and 35.4% of the women aged 18 to 25 had none of these risk factors and exhibited the best physical performance. The more risk factors were present, the worse physical performance became. The 24- and 25-year-olds performed at the same level as the 14- and 15-year-olds.

DISCUSSION

Unhealthy lifestyles can impair physical fitness even before any chronic disease arises. Possession of even a single risk factor is associated with significantly worse performance. Unless comprehensive and effective interventions are introduced in school and at work, the further cementation and worsening of unhealthy lifestyles will be hard to stop.

Associations between pedagogues attitudes, praxis and policy in relation to physical activity of children in kindergarten--results from a cross sectional study of health behaviour amongst Danish pre-school children

This paper reports on associations between physical activity, pedagogue's attitudes towards promoting physical activity and the physical activity policies (PAP) in kindergarten. The paper deals with data on physical activity of 3-6 year olds in kindergarten which originates from a cross-sectional study conducted in 2006 among all Danish kindergartens. A questionnaire of 48 questions based on pedagogues assessment regarding the health related polcies and praxis in kindergarten and the attitudes of pedagogues was mailed (n = 4200) to all institutions in the country. In total, 1149 kindergartens and 693 integrated institutions returned the survey. The results show a relation between pedagogue's attitudes towards promoting children's physical activity and the number of children having moderately intense physical activity for at least one hour a day. The study also shows a positive association between policies and pedagogue's attitudes towards promoting children's physical activity and the number of days that pedagogues initiated games that made the children physically active. The study suggests that the social and organizational environment in the kindergarten is an important determinant for the level of physical activity among children. This means that the individual norms and attitudes of pedagogues along with the collective intentions and values expressed in written and adopted organizational policies (a Physical Activity Policy--PAP) are important aspects to be worked upon if kindergarten should play an active role in the promotion of healthy lifestyle among kindergarten aged children. Strong municipal and institutional leadership as well as educational interventions in the curricula of pedagogues could be important ways to bring about such change.

Promoting strength and balance in adolescents during physical education: effects of a short-term resistance training

Secular trends in strength and postural control have been reported for children and adolescents. Therefore, the objective of this study was to investigate the impact of a short-term ballistic strength training (BST) followed by detraining on measures of strength and postural control in adolescents. Twenty-eight high-school students participated in this study and were assigned to either an intervention (n = 14, age 16.7 ± 0.6 years, body mass index [BMI] 21.1 ± 1.7 kg · m) or a control group (n = 14, age 16.8 ± 0.7 years, BMI 19.9 ± 1.7 kg · m). The intervention class participated in a short-term (8 week) lower extremity BST program 2 times a week integrated in their regular physical education lessons. Pre, post, and follow-up tests included the measurements of maximal isometric force (MIF) and rate of force development (RFD) of the leg extensors on a leg press with the feet resting on a force platform, vertical jumping height (countermovement jump [CMJ]) on a force plate and the assessment of static (1-legged stance on a balance platform), and dynamic (mediolateral perturbation impulse on a balance platform) postural control. Ballistic strength training resulted in statistically significant improvements in MIF (p = 0.001) and CMJ height (p < 0.001), which were still present after detraining for MIF (p = 0.04). Furthermore, tendencies in terms of small to medium interaction effects yet not statistically significant improvements were found for RFD (p = 0.38), and measures of static (p = 0.15) but not of dynamic postural control. In adolescents, lower extremity BST is a suitable training modality for the application in a school setting (particularly during physical education lessons) that produced transient improvements in strength variables. These results could have an impact on improving the performance level in various motor fitness skills and sports activities in physical education.

Cross-sectional trends in cardiovascular fitness in Swedish 16-year-olds between 1987 and 2007

AIM

We sought to investigate the temporal trends in estimated maximal aerobic capacity in adolescents (mean age 16.1).

METHODS

Analyses were based on data from three population-based samples, collected in 1987 (n=221), 2001 (n=537) and 2007 (n=265). Subjects underwent sub-maximal ergometer testing. Absolute and relative aerobic capacities were estimated using the Åstrand-Ryhming nomogram.

RESULTS

Compared to 1987, values for estimated relative and absolute maximal aerobic capacities were lower in 2001 and 2007, and values in 2007 were lower compared to 2001, in both boys and girls, except for absolute capacity between 1987 and 2001 in girls. The differences over time did not differ between genders. Absolute values changed from 3.0 and 2.5 L/min in 1987 to 2.5 and 2.2 L/min in 2007, for boys and girls, respectively. Relative values changed from 46.5 and 45.9 mL/min/kg in 1987 to 35.0 and 36.6 mL/min/kg, in 2007, for boys and girls, respectively.

CONCLUSION

Based on earlier reports on the relationship between aerobic capacity and metabolic risk, the results from the present study provide argument that future public health will be affected negatively.

An activity-based intervention for obese and physically inactive children organized in primary care: feasibility and impact on fitness and BMI A one-year follow-up study

OBJECTIVE

To investigate the feasibility and impact on BMI and physical fitness of an intervention for obese and inactive children, based on physical activity and carried out in primary health care.

DESIGN

A prospective, longitudinal one-year follow-up study.

SETTING

The community of Kristiansand, Norway (80 000 inhabitants).

INTERVENTION

A 40-week structured intervention based on physical training with some lifestyle advice for the obese child and one parent. Subjects. A total of 62 physically inactive children aged 6-14 years with iso-BMI ≥ 30 kg/m².

MAIN OUTCOME MEASURES

Body mass index (BMI), maximum oxygen uptake, and physical fitness in tests of running, jumping, throwing, and climbing assessed at baseline and after six and 12 months as well as number of dropouts and predicting factors.

RESULTS

A total of 49 out of 62 children completed the first six months and 37 children completed 12 months. Dropout rate was higher when parents reported being physically inactive at baseline or avoided physical participation in the intervention. The children's maximum oxygen uptake increased significantly after 12 months from 27.0 to 32.0 ml/kg/min (means), as did physical fitness (endurance, speed, agility, coordination, balance, strength) and BMI was significantly reduced.

CONCLUSION/IMPLICATIONS

This one-year activity-based intervention for obese and inactive children performed in primary health care succeeded by increasing cardiovascular capacity and physical fitness combined with reduced BMI in those who completed. Dropout was substantial and depended on the attendance and compliance with physical activity by the parents.

Secular trends in muscular fitness among Finnish adolescents

AIM

To investigate secular change over time in health-related muscular fitness and how leisure time physical activity (LTPA), sport club participation, and body mass index are associated with muscular fitness in adolescents.

METHODS

Two cross-sectional samples of Finnish 13-16-year-old adolescents were studied in 1976 (n = 643; 312 boys and 331 girls) and in 2001 (n = 579; 308 boys and 271 girls). Muscular fitness index was calculated as the sum of age- and sex-specific z-scores of four tests measuring muscular fitness and agility. Height and weight were also measured. Self-reported weekly frequency of LTPA of at least 30-min duration and regularity of participation in organised sport were obtained by questionnaire. Identical methods were used in 1976 and 2001.

RESULTS

Muscular fitness index was higher in 2001 than in 1976 in both boys (by 0.77 points, p = 0.008, effect size d = 0.17, small difference) and girls (1.01 points, p = 0.004, d = 0.20, small difference). Sport club participation, body mass index, and participation in LTPA together explained more of the muscular fitness index variance in 2001 than in 1976 in both boys (coefficient of determination from 0.10 to 0.24) and girls (from 0.25 to 0.40).

CONCLUSIONS

The muscular fitness of 13-16-year old adolescents slightly improved over time. Organised LTPA showed a stronger association with muscular fitness in 2001 than in 1976. Due to increased polarisation in fitness, in health promotion more attention should be paid on adolescents' health-related fitness and its association to LTPA.

Changes in fitness, body mass index and obesity in 9-10 year olds

BACKGROUND

The prevalence of obesity in children has increased substantially in recent years and, paediatric obesity and poor fitness are risk factors for disease. The present study aimed to assess changes in body mass index (BMI), the prevalence of obesity and changes in aerobic endurance over time in 9-10-year-old schoolchildren.

METHODS

Participants were recruited by the SportsLinx project from primary schools across Liverpool. Height and weight data were used to calculate BMI. The prevalence of obesity and overweight were estimated using age- and sex-specific cut-off points. Performance on the 20-m multi-stage shuttle runs test (20 mMST) was used as a marker of aerobic endurance. Data were available for 13,418 (6572 boys, 6846 girls) 9-10-year-old children. Analysis of covariance was completed to assess year-on-year changes in BMI controlling for deprivation (IMD) and 20 mMST performance, and 20 mMST performance controlling for IMD and BMI.

RESULTS

No significant changes in BMI from baseline were observed (P > 0.05). Obesity prevalence reduced in girls (2005 = 10.3%, 2008 = 8.52% in 2008). The data for boys showed no reductions in prevalence (2005 = 6.77%, 2008 = 7.87%). The most recent cohort for boys and two most recent cohorts for girls had lower levels of aerobic endurance than baseline (2004-2005) (P <or= 0.01).

CONCLUSIONS

The data suggest a plateau in the yearly increases in BMI in 9-10 year olds independent of deprivation and fitness and a declining prevalence of obesity in girls. Levels of aerobic endurance have declined independent of BMI and deprivation. The current obesity interventions in place appear to be having some impact on BMI, but further investment is urged to promote fitness in children.

Motor competence and physical activity in 8-year-old school children with generalized joint hypermobility

OBJECTIVE

Because the criteria used for diagnosing between generalized joint hypermobility (GJH) and musculoskeletal complaints, as well as relations between GJH and an insufficient motor development and/or a reduced physical activity level differ, the prevalence of GJH varies considerably. The aim of this study was to survey the prevalence of GJH defined by a Beighton score at >or=4, >or=5, or >or=6 positive tests of 9 and benign joint hypermobility syndrome (BJHS) in Danish primary school children at 8 years of age. A second aim was to compare children with and without GJH and BJHS regarding motor competence, self-reported physical activity, and incidence of musculoskeletal pain and injuries.

METHODS

A cross-sectional study of 524 children in the second grade from 10 public schools was performed. A positive response rate was obtained for 416 (79.4%) children, and 411 (78.4%) children were clinically examined and tested for motor competence, whereas questionnaire response to items comprising musculoskeletal pain and injuries, in addition to daily level and duration of physical activity, corresponded to 377 (71.9%) children.

RESULTS

In total, 29% of the children had GJH4, 19% had GJH5, 10% had GJH6, and 9% had BJHS, with no gender difference. There was no difference in daily level and duration of physical activity and in frequency of musculoskeletal pain and injuries between those with and without GJH. Children with >or=GJH5 as well as with >or=GJH6 performed better in the motor competence tests.

CONCLUSION

Motor competence and physical activity are not reduced in primary school children at 8 years of age with GJH or BJHS. It is recommended that a potential negative influence on the musculoskeletal system over time, as a result of GJH, be investigated by longitudinal studies.

Questionnaire-assessed moderate to vigorous physical activity of the Finnish youth in 1979-2005

The purpose of the study was to investigate the time trend of questionnaire-assessed moderate to vigorous physical activity (MVPA) among 12-18-year-old Finnish boys and girls from 1979 to 2005. The MVPA was defined as "at least moderately breathtaking and sweating in leisure time physical activities more than 3 times week." Data were based on the Adolescent Health and Lifestyle Survey, which is a biannual, nation-wide survey on adolescent health and health-related lifestyle in Finland. The nationally representative samples were drawn from the Finnish Population Register Centre. The numbers of participants varied from 2832 to 8390 and the response rates from 91% (girls, 1981) to 58% (boys, 2005). The main results showed that the participation rate in MVPA increased during the study period. The increase was not continuous, but showed an upward trend during the years 2001-2005. The study also revealed that boys participated in MVPA more than girls. However, the gender difference decreased during the study period. Age differences in MVPA were rather small and they decreased during the study period. However, perceived intensity of physical activity was higher among older than younger groups, whereas participation in MVPA was more frequent in younger than older groups. The results supported the findings of some previous studies that reported that especially in Finland the vigorous physical activity among young people had consistently increased. This study gave more information about this phenomenon because the study period was longer, 26 years, and the sample also included older, 16- and 18-year-old boys and girls.

Cardiorespiratory fitness and body mass index values in 9-year-old rural Norwegian children

AIM

To describe cardiorespiratory fitness and body mass index (BMI) values in a representative population of 9-year-old Norwegian children in two rural communities and compare present values with previous findings.

METHODS

Two hundred and fifty-nine 9-year-old children were invited, and 256 participated in this study. Maximal oxygen uptake was directly measured during a continuous progressive treadmill protocol. Body mass and height were also measured.

RESULTS

The mean +/- SD relative maximal oxygen uptake was 52.8 +/- 6.5 for boys and 46.9 +/- 7.2 mL/kg/min for girls. Eight percent of the boys and 16.8% of the girls were classified as overweight, and 1.6% of the boys and 6.9% of the girls as obese. Mean age, body mass, height and Ponderal index were not significantly different between sexes. Girls had a higher BMI than boys (p = 0.05).

CONCLUSION

Compared to earlier Norwegian studies, children's BMI values seem to have increased substantially. This increase is most pronounced in girls. When assessing these differences using the PI, this increase is less marked. Comparing maximal oxygen uptake data with that in earlier Nordic studies, there is no evidence that fitness has declined among 9-year olds. However, the limitations of the few earlier studies make reliable comparisons difficult.

"There's nothing I can't do--I just put my mind to anything and I can do it": a qualitative analysis of how children with chronic disease and their parents account for and manage physical activity

BACKGROUND

This paper reports the findings of a South Australian qualitative, exploratory study of children and young people living with a chronic disease, and their perceptions and experiences of physical activity. The perceptions and experiences of their parents were also explored. The chronic diseases were type 1 diabetes, asthma and cystic fibrosis.

METHODS

Multiple qualitative data collection techniques were used to elicit the children and young people's perspectives and experiences of physical activity, including focus groups, maps, photos and 'traffic light posters'. The children's parents were interviewed separately to ascertain their views of their child's participation in physical activities.

RESULTS

Children and young people described their active participation in a wide variety of physical activities including organised sports and play, but made very little mention of any negative influence or impact due to their disease. Their parents' stories described the diligent background planning and management undertaken to enable their child to participate in a wide range of physical activities.

CONCLUSION

The results of this study suggest that for these children and young people, having a chronic disease was not perceived as a barrier to participation in organised sport and recreational activities. They were physically active and perceived themselves to be no different from their peers. Their positive beliefs were shared by their parents and the level of participation described was enabled by the high level of parental support and background planning involved in managing their child's health care needs.