Increasing trends in childhood overweight have mostly reversed: 30 years of continuous surveillance of Slovenian youth

Positive secular trend in excess body weight in adolescents: A comparative study of 2007 and 2017/2018 data

BACKGROUND

This study aimed to compare the prevalence of excess weight in adolescents living in Florianópolis, Santa Catarina, Brazil, from 2007 to 2017/2018 and assess associations with physical activity level, screen time, muscle strength, and cardiorespiratory fitness.

METHODS

Two cross-sectional surveys were conducted with adolescents (14 to 19 years old). The body mass index was calculated from measurements of body weight (kg) and height (m2). Information on sociodemographic variables (sex, age, and economic level), screen time, and physical activity was collected using questionnaires. Motor tests were used to measure cardiorespiratory fitness and muscle strength.

RESULTS

A positive secular trend in excess weight was observed in adolescents between 2017/2018 and 2007. Boys who spent more than 4h a day on screen-based activities and those with inadequate cardiorespiratory fitness were 1.96 and 3.03 times more likely, respectively, to have excess weight in 2017/2018 than in 2007. Boys (OR = 1.77) and girls (OR = 1.74) with inadequate muscle strength were more likely to have excess weight in 2017/2018 than their peers in 2007. Furthermore, boys and girls with adequate cardiorespiratory fitness had 64% and 90% lower chances, respectively, of having excess weight in 2017/2018 than in 2007.

CONCLUSIONS

A decade of observation revealed a positive secular trend in excess weight in adolescents, with significant associations with muscle strength, cardiorespiratory fitness, and screen time.

Prevalence of Overweight and Obesity and Association with Risk Factors in Secondary School Children in Croatia

BACKGROUND

Childhood and adolescent overweight and obesity represent significant global health concerns. The primary objective of this study was to assess the prevalence and associations of some potential risk factors with overweight and obesity among Croatian adolescents aged 15 to 18.

METHODS

This cross-sectional study included 344 secondary school students from Croatia's Mediterranean region, with data collected through an anonymous questionnaire. The questionnaire gathered sociodemographic information, adherence to the Mediterranean diet of both children and their parents, and the children's dietary habits and physical activity levels.

RESULTS

Weight status data revealed that 2.6% of participants were underweight, 82% had normal weight, 11% were overweight, and 4.4% were classified as obese. The results indicated that boys (p < 0.001), children who skip breakfast (p = 0.031), those with less active lifestyles compared to their peers (p = 0.001), children whose mothers have a higher BMI (p < 0.001), and children from smaller families (p = 0.034) are at greater risk of being overweight or obese.

CONCLUSIONS

This study provides valuable insights into the risk factors associated with overweight and obesity in this age group, which can support the development of targeted strategies for this population.

Body Composition Trend in Slovene Adults: A Two-Year Follow-Up

This research re-evaluates the prevalence of obesity in a cohort of 432 Slovenian adults two years after an initial population-based cross-sectional examination, utilizing the World Health Organization's body mass index (BMI) and total body fat percentage (FAT%) classifications. Herein, a medically approved electrical bioimpedance monitor was used to analyse body composition, and the results revealed a significant increase in the percentage of individuals classified as having overweight or obesity on the basis of BMI, from 40.7% initially to 45.2% at follow-up (FU); however, these percentages were notably higher in males than in females. The increases in body mass, BMI, fat mass, and FAT% were observed mainly in adult females, whereas in adult males, the increases in BM and BMI were attributed to fat-free mass (FFM) rather than fat mass. In this study, BMI was also compared with the FAT% obesity classification, and the BMI classification was shown to result in significantly fewer participants with obesity in both measures. However, the proportion of participants with obesity based on the two classifications did not differ substantially between the initial and FU measurements. In this study, mixed linear models were used to analyse overall trends and subgroup variations and highlight the importance of considering sex, age, and time of measurement when assessing body composition metrics. These findings emphasize the need for personalized health assessments and the importance of measuring body composition to evaluate adult obesity more accurately for both clinical assessments and public health policies. The state, in collaboration with social initiatives and industrial stakeholders, should prioritize these data and advance public health through innovative educational and awareness initiatives that are founded on robust scientific principles and that empower and promote the adoption of a healthy, active lifestyle.

Temporal trends in weight-based disparities in physical fitness of children: 30-years of continuous surveillance through Slovenian national system

BACKGROUND

Obesity in childhood has deleterious consequences for health while improving physical fitness can significantly reduce health risks related to high body mass index. We aimed to examine the evolution of disparities in physical fitness based on weight status among 7-15-year-olds in Slovenia between 1989 and 2019 and compare these trends across sex, age and socioeconomic status.

METHODS

We used annual data collected within the SLOfit monitoring system in the period between 1989 and 2019, totalling 4,256,930 participants (about 137 000 per year). We examined cardiorespiratory fitness (600-m run test), muscular fitness (60-s sit-ups, bent arm hang, and standing broad jump test) and skill-related fitness (backwards obstacle course, 60-m dash, arm plate tapping). We grouped children according to the IOTF cut-offs for BMI to those living with normal weight or excess weight and estimated changes in physical fitness over time by fitting quantile regression models separately by sex and age group, and then using segmented regression to identify the patterns of trends over time.

RESULTS

Weight-based disparities in physical fitness were large in 1989 and have further increased by 2019. The increase in disparities was generally around 5 percentiles larger in boys, and 10-15-year-olds compared to younger children. It was particularly pronounced for body core strength and speed in boys (up to 15 and 19 percentiles, respectively) and upper body strength and speed among girls (up to 13 percentiles). Most of the increase in disparities in health-related fitness accumulated during the 2010s, when the fitness of children generally improved, but much less so in children living with excess weight.

CONCLUSIONS

Despite recent improvements in population fitness levels, children with excess weight seem to be left behind, which adds to existing health inequalities. Our results should encourage policymakers to redesign policies aimed at promoting physical activity and enhancing physical fitness to make them more equitable and ultimately lead to reducing inequalities in fitness.

Rising socioeconomic disparities in childhood overweight and obesity in Belgium

BACKGROUND

Childhood overweight, especially obesity, significantly impacts children's health and poses an increased risk of adult-onset diseases. This study aims to analyse the evolution of childhood overweight and obesity in Belgium from 1997 to 2018 and assess its variation across parental socioeconomic status (SES).

METHODS

The Health Interview Survey, a cross-sectional survey representative of the Belgian population, has been conducted since 1997, with the latest survey conducted in 2018. This study focuses on children aged 2-17 years. Body Mass Index (BMI, kg/m²) was derived from self-reported data, supplemented with proxy reports for children under 15 years old. Overweight and obesity were classified using age/sex-specific cut-off points. Highest parental educational level served as the indicator of SES. In addition to reporting the overall prevalence and the 95% confidence interval (95%CI) of childhood overweight and obesity by year, this study examines the absolute difference in prevalence between SES groups (low minus high) and calculates the Odds Ratio (OR, adjusted for age and sex) to evaluate the relative difference.

RESULTS

The overall prevalence of childhood overweight rose from 13.6% (95%CI = 11.2-16.1%) in 1997 to 18.9% (95%CI = 16.3-21.5%) in 2018; while it remained stable for obesity, fluctuating between 5.4% and 6.3% over the same period. This increase was more pronounced among children with low SES compared to those with high SES. Consequently, the absolute difference between children with low and high SES increased over time from 8.0% points (pp) in 1997 to 14.9 pp in 2018 for overweight, and from 3.1 pp to 6.8 pp for obesity. In terms of relative inequalities, overall, children with low SES exhibited significantly higher odds of overweight and of obesity than those with high SES (OR varying between 2 à 3 for overweight and between 2 and 4 for obesity).

CONCLUSIONS

The escalating disparities over time highlight SES as a significant risk factor for childhood overweight and obesity. Addressing these inequalities requires interventions such as providing healthy meals and increasing sports opportunities at school. Additionally, it is recommended to regulate fast food outlets near schools and limit unhealthy food marketing, particularly because children with low SES are more exposed to such influences.

Vegan Diets for Children: A Narrative Review of Position Papers Published by Relevant Associations

The scientific discourse on vegan diets for children and adolescents primarily involves referencing position statement papers from different scientific and professional organizations, including paediatric associations. Over the past two decades, specialized associations have issued official statements and published position papers about adopting well-designed vegan diets during crucial life stages, including pregnancy and lactation, infancy, and childhood. A subset of these associations firmly supports the notion that a well-designed vegan diet can indeed be healthy and support normal growth and development during particularly delicate life stages, emphasizing careful planning, vitamin B12 supplementation, and regular supervised medical and dietetics oversight. In contrast, specific paediatric associations caution against vegan diets for children and adolescents, citing potential harm and the lack of adequate substantiation. These criticisms in position papers frequently point to lower-quality studies and/or outdated studies. Additionally, concerns extend to comparing vegan and omnivorous diets, considering public health issues such as obesity and early stages of cardiovascular disease as well as the risk of prediabetes and type 2 diabetes. Notably, some scepticism stems from studies where children's adherence to a well-designed vegan diet is incomplete. Scientific rigor suggests performing a comparable assessment of omnivorous and vegan diets. This narrative review highlights the need for a comprehensive, up-to-date literature review to inform balanced perspectives on vegan diets for children and adolescents. Researchers and decision-makers should aim to actively improve the design and consistent implementation of both diet types.

The Activities of the Slovenian Strategic Council for Nutrition 2023/24 to Improve the Health of the Slovenian Population and the Sustainability of Food: A Narrative Review

The health status of individuals in Slovenia across age groups is a matter of concern, as current unsustainable lifestyle choices are already leading to various chronic noncommunicable diseases (NCDs). Outdated national dietary guidelines, their inconsistent implementation, and a lack of structural changes represent obstacles to promoting healthy and sustainable nutrition. Limited access to and rising prices of healthy, sustainable foods, in addition to the high availability of low-priced, highly processed foods, increase the risk of NCDs. The lack of systematic health monitoring and early disease detection poses a challenge. Global and local environmental issues, resistance, and/or the inability to adopt healthier diets hinder individuals from changing their nutritional behaviours. In this narrative review, we provide an overview of the current situation in Slovenia as well as planned activities initiated by the Slovenian government and the Prime Minister's Strategic Council for Nutrition, aiming to make progress in supporting healthy and sustainable nutrition, limiting food waste, and increasing the availability of healthier foods for all. Improving the sustainability of the Slovenian food system can contribute to several Sustainable Development Goals (SDGs), ensuring Slovenia's commitment to internationally agreed-upon targets. This could lead Slovenia to take a role as a pilot country in testing and implementing the necessary systemic changes, which could be further applied in other countries.

Challenges of social change: The 2021 Republic of Slovenia report card on physical activity of children and adolescents

Background

Slovenian children are facing considerable health challenges from the rapid social changes that influence their opportunity to engage in daily physical activity.

Objective

To overlay the social changes to the established Report Card model as a means of contextualising the extreme changes in physical activity and fitness observed over several years.

Methods

Benchmarks were graded for 10 core indicators, plus two (Sleep, Seasonal Variations). Active Healthy Kids Slovenia members met (predominantly via zoom) liaising with team leader(s) on a flexible, individual basis, based on coronavirus disease 2019 (COVID-19) regulations, over the ∼2-year assessment period of the project. Data were separated to the years prior to, 'pre' 2018-2020, and 'during' the global pandemic (2020-2021). Where sufficient data existed for both timeframes, grades were averaged to produce an overall grade.

Results

Grade results are expressed as pre/during/final grade, where the final grade (bolded) is a straight average of the two preceding time epochs: Overall Physical Activity (A-/A-/A-), Organized Sport and Physical Activity (C+/C/C), Active Play (D/C+/C), Active Transport (C/INC/C), Sedentary Behaviour (B/C/C+), Physical Fitness (A+/A-/A), Family and Peers (B+/INC/B+), Schools (A/A/A), Community and Environment (A+/A+/A+), Government (A/F/D), Sleep (D-/INC/D-), Seasonal Variations (D/C-/D+).

Conclusion

Although Slovenia has some of the most consistently physically-active children in the world, the effects of the COVID-19 pandemic exerted significant reductions in physical activity opportunities, and especially when coupled with funding re-distributions, resulted in the steepest decline of child physical fitness observed within the >35-year history of Slovenia's well-established national fitness surveillance system.

Centile Reference Curves of the SLOfit Physical Fitness Tests for School-Aged Children and Adolescents

ABSTRACT

Blagus, R, Jurak, G, Starc, G, and Leskošek, B. Centile reference curves of the SLOfit physical fitness tests for school-aged children and adolescents. J Strength Cond Res 37(2): 328-336, 2023-The study provides sex- and age-specific centile norms of Slovenian children and youth. Physical fitness was assessed using the SLOfit test battery on population data, including 185,222 children, aged 6-19 years, measured in April and May 2018. Centile curves for both sexes and 12 test items were constructed using the generalized additive models for location, scale, and shape (GAMLSS). Boys generally achieved higher scores in most of the physical fitness tests, except in stand and reach, but this was not consistent throughout childhood and adolescence, nor did it pertain to the entire range of performance. Girls outperformed boys in the arm-plate tapping test throughout childhood; the poorest performing girls outperformed the poorest performing boys in the 600-m run, 60-m dash, backward obstacle course, and standing broad jump. The shapes and trends of physical fitness curves adequately reflect the effects of growth and development on boys' and girls' physical performance. Comparing the existing reference fitness curves showed that Slovenian children and adolescents display higher fitness levels than their peers from other countries. This study provides the most up-to-date sex- and age-specific reference fitness centile curves of Slovenian children, which can be used as benchmark values for health and fitness monitoring and surveillance systems.

Trends of overweight and obesity prevalence in school-aged children among Henan Province from 2000 to 2019

Objectives

Overweight and obesity are harmful to human health. However, the latest trends of Chinese childhood overweight and obesity prevalence are not available. The aim of this study was to examine the trends from 2000 to 2019 among students in China.

Methods

We analyzed data of 66,072 students in the Chinese National Survey on Students' Constitution and Health from 2000 to 2019. Overweight and obesity were defined based on the standard formulated by the International Obesity Task Force (IOTF standard), the World Health Organization (WHO standard), and the Working Group on Obesity in China (WGOC standard), respectively. The χ²-test was used to test the trends of overweight and obesity prevalence and logistic regression was conducted to evaluate the prevalence odds ratios of boys vs. girls and urban vs. rural areas.

Results

The prevalence of obesity/overweight and obesity combined was 6.03/23.58% (IOTF standard), 10.56/25.88% (WGOC standard) and 10.75/29.69% (WHO standard) in 2019. From 2000 to 2019, according to the WGOC standard, the prevalence increased from 2.51 to 10.56% for obesity and increased from 9.81 to 25.88% for overweight and obesity combined (P for trend < 0.001). Obesity/overweight and obesity were greater problems in boys than girls and urban than rural areas, but urban-rural differences decreased over time.

Conclusion

Overweight and obesity prevalence increased significantly in children and adolescents in China from 2000 to 2019. The prevalence of overweight and obesity in rural areas may contribute to a large percentage of children with overweight and obesity.

Multiparametric MR radiomics in brain glioma: models comparation to predict biomarker status

Background

Genotype status of glioma have important significance to clinical treatment and prognosis. At present, there are few studies on the prediction of multiple genotype status in glioma by method of multi-sequence radiomics. The purpose of the study is to compare the performance of clinical features (age, sex, WHO grade, MRI morphological features etc.), radiomics features from multi MR sequence (T2WI, T1WI, DWI, ADC, CE-MRI (contrast enhancement)), and a combined multiple features model in predicting biomarker status (IDH, MGMT, TERT, 1p/19q of glioma.

Methods

In this retrospective analysis, 81 glioma patients confirmed by histology were enrolled in this study. Five MRI sequences were used for radiomic feature extraction. Finally, 107 features were extracted from each sequence on Pyradiomics software, separately. These included 18 first-order metrics, such as the mean, standard deviation, skewness, and kurtosis etc., 14 shape features and second-order metrics including 24 grey level run length matrix (GLCM), 16 grey level run length matrix (GLRLM), 16 grey level size zone matrix (GLSZM), 5 neighboring gray tone difference matrix (NGTDM), and 14 grey level dependence matrix (GLDM). Then, Univariate analysis and LASSO (Least absolute shrinkage and selection operator regression model were used to data dimension reduction, feature selection, and radiomics signature building. Significant features (p < 0.05 by multivariate logistic regression were retained to establish clinical model, T1WI model, T2WI model, T1 + C (T1WI contrast enhancement model, DWI model and ADC model, multi sequence model. Clinical features were combined with multi sequence model to establish a combined model. The predictive performance was validated by receiver operating characteristic curve (ROC analysis and decision curve analysis (DCA).

Results

The combined model showed the better performance in some groups of genotype status among some models (IDH AUC = 0.93, MGMT AUC = 0.88, TERT AUC = 0.76). Multi sequence model performed better than single sequence model in IDH, MGMT, TERT. There was no significant difference among the models in predicting 1p/19q status. Decision curve analysis showed combined model has higher clinical benefit than multi sequence model.

Conclusion

Multi sequence model is an effective method to identify the genotype status of cerebral glioma. Combined with clinical models can better distinguish genotype status of glioma.

Key Points

The combined model showed the higher performance compare with other models in predicting genotype status of IDH, MGMT, TERT.

Multi sequence model showed a better predictive model than that of a single sequence model.

Compared with other models, the combined model and multi sequence model show no advantage in prediction of 1p/19q status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00865-8.

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.

Prevalence of arterial hypertension among Ukrainian students: the comparison of European and American guidelines

INTRODUCTION

Arterial hypertension (HTN) among children is progressively increasing. These concerns have led to an update of the guidelines about childhood hypertension by the European Society of Hypertension (ESH) in 2016 and the American Academy of Pediatrics (AAP) in 2017, and their thresholds for HTN differ. The current research aims to compare the prevalence of hypertension in Ukrainian teenagers using 2 different guidelines and to check the impact of gender, age, and excess weight on hypertension.

MATERIAL AND METHODS

The sample includes 540 Ukrainian students of 2 secondary urban schools, aged 10-17 years. Blood pressure and anthropometrical measurements were taken and compared with percentile tables.

RESULTS

The prevalence of abnormal BP (11.3% and 15.2%) and HTN (1.9% and 4.1%) was determined with ESH and AAP guidelines, respectively, and they strongly depended on which definitions and criteria were used. Boys were much more predisposed to abnormal BP. Comparing both guidelines, there was no significant difference in HTN prevalence in children aged 10-12 years; nevertheless, AAP recognized HTN almost twice as often in teenagers aged ≥ 13 years. Excess body weight was identified in 17.2% of the school-age children, twice as frequently as in males.

CONCLUSIONS

The results have shown a higher prevalence of HTN in teenagers and children with excessive weight more significant in boys and between children with positive markers of abdominal obesity due to both guidelines, without a significant difference in prevalence after re-classification; however, AAP recommendations might be preferable.

Secular trends in muscular fitness from 1983 to 2014 among Slovenian children and adolescents

Low physical fitness has been found to be associated with many chronic diseases and medical conditions. Knowledge of secular trends in physical fitness is important to initiate countermeasures for addressing negative trends. The aim of this study was to analyze secular trends in health-related muscular fitness in Slovenian children and adolescents between 1983 and 2014. Data were collected as part of "The Analysis of Children's Development in Slovenia (ACDSi)" study in 1983, 1993/94, 2003/04, and 2013/14. Anthropometry (body weight, height, BMI, and triceps skinfold) and muscular fitness (standing long jump, bent-arm hang, and sit-ups 60 s test) of 18730 (9168 female) students from primary and secondary schools were recorded. The secular trend was analyzed considering anthropometry. The results showed that anthropometric measures had an increasing trend and overall muscular fitness had a decreasing trend. Leg muscle power decreased over the decades in all age groups (relative difference between -1.5% and -2.6%), being more pronounced in boys. Arm muscle strength decreased in two younger age groups (range -21.1% to -42.7%, 6-10, and 11-14 years), but not in the oldest group (15-19 years), where the increase occurred in both genders (0.4% to 9.3%). In terms of decades, the largest negative changes (-30.1%) occurred from 1993/94 to 2003/04 and the smallest changes (-4.2%) from 2003/04 to 2013/14. The overall trend in repetitive core strength surprisingly increased (1.1% to 18.3%). There is a need to promote healthy lifestyles, raise parental awareness and use all government resources to redirect the negative trend in physical fitness.

Secular Trends of Underweight, Overweight, and Obesity in Children and Adolescents from Ukraine

Overweight and obesity, as well as underweight in children and adolescents, pose a significant public health issue. This study aimed to investigate the secular trend of the incidence of underweight, overweight, and obesity in children from Ukraine in 2013/2014 and 2018/2019. The studies were conducted in randomly selected primary and secondary schools in Ukraine. In total, 13,447 children (6468 boys and 6979 girls) participated in the study in 2013/2014 and 18,144 children (8717 boys and 9427 girls) participated in 2018/2019. Measurements of body weight and height were performed in triplicate. Underweight, overweight, and obesity were diagnosed according to the standards of the World Health Organization (WHO). In the group of girls, a significant difference between 2013/2014 and 2018/2019 measurements was found only among 7-year-olds. The percentage of girls at this age exceeding the body mass index (BMI) norm was lower in the 2018/2019 study. In boys, a significant difference was also found in 7-year-olds, and, as in girls, a lower share of overweight and obesity was found in 2018/2019. But for the ages of 12, 13, and 15, the significant differences had a different character-more overweight or obese boys were found in the 2018/2019 study. The proportion of underweight children was similar for the majority of age groups in both genders and did not differ in a statistically significant way.

Assessment of Secular Trends and Health Risk in Pediatric Cardiorespiratory Fitness From the Republic of Slovenia

Objectives

Determine the temporal trends in cardiorespiratory fitness (CRF) and health risk of Slovenian schoolchildren across a 20-year span, assessed via 20-m shuttle run (20mSRT), including defining centile ranges and possible health risk(s) for each generation.

Methods

Nationally representative data from 9,426 healthy schoolchildren (6–14 years old) were used to determine changes in CRF across three generations, in 1993 (n = 3,174), 2003 (n = 3,457) and 2013 (n = 2,795) from a multistage, stratified, decennial study.

Results

20mSRT performance declined ∼2.8% from 1993 to 2003, independent of age or sex of the child. This trend was reversed in 2013, increasing by ∼8.2% across all age groups, for both girls and boys, for a net increase of 5.4%. The magnitude of improvement was similar for both sexes. Moreover, girls in the 2013 generation (for ages 10–13 year) completed more stages than their 2003 male counterparts. Across all generations, children achieved CRF values corresponding to low cardiovascular risk for future health outcomes. Centile values ranged from “low” to “very high” depending on age, sex, and generation of the sample.

Conclusion

Negative trends in CRF from Slovenian schoolchildren were reversed by 2013, indicating that Slovenia should continue implementing progressive national physical fitness strategies introduced between sampling periods (i.e., 2003–2013). Additionally, due to the universal nature of Slovenian schoolchildren achieving “healthy cut-off values” for 20mSRT (generation-inclusive), it is suggested that more specific cut-off criteria are developed, especially for younger children, and girls, so that future CRF results can be more accurately applied for both clinical and pedagogical users.

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.