How to design and establish a national school-based physical fitness monitoring and surveillance system for children and adolescents: A 10-step approach recommended by the FitBack network.

BACKGROUND: Providing individual- and population-level data on children's physical fitness (PF) is a crucial public health and education priority. However, few national fitness monitoring or surveillance systems are currently in practice internationally. We aim to summarize the current European PF monitoring and surveillance systems for school-aged children and to provide experience-based guidelines on how to design such systems. METHODS: The FitBack network consists of experts from diverse backgrounds with the common interest to improve the accessibility of PF monitoring for young people globally. Through FitBack network, we identified and compared the national or regional PF monitoring and surveillance systems currently in operation across Europe. We formulated a 10-step approach for designing and establishing one's own system, based on analysis of experienced strengths, weaknesses, opportunities, and threats to monitoring childhood fitness. RESULTS: We identified a total of eight PF monitoring systems in Finland, France, Galicia of Spain, Hungary, Lithuania, Portugal, Serbia, and Slovenia. The FitBack network recommends the following steps for designing and establishing one's own system: (1) set up mission statements and aims, (2) involve stakeholders, (3) utilize scientific background, (4) governance structure, (5) ensure sufficient funding, (6) data management planning, (7) provide meaningful feedback, (8) conduct pilot testing, (9) plan implementation process, and (10) invest in communication with stakeholders. CONCLUSIONS: This study provides an updated overview of the best practices for school-aged children's fitness monitoring and surveillance in Europe. Additionally, it offers a 10-step approach to assist in the creation of similar systems in Europe or globally.

Physical fitness among children with diverse weight status during and after the COVID-19 pandemic: a population-wide, cohort study based on the Slovenian physical fitness surveillance system (SLOfit).

Background: COVID-19 public health crisis has exerted immediate negative impacts on children's physical fitness, but the longer-term effects are not clear, and the impact on children with excess weight is yet unknown. We examined changes in multiple components of physical fitness in response to COVID-19 imposed restrictions, but also a year after the restrictions were terminated, and compared these trends in groups of boys and girls with normal weight, overweight, or obesity before the pandemic. Methods: Information was gathered through Slovenia's national fitness surveillance system, and included 41,330 children (19,890 girls), aged 5-17, who had their fitness levels measured yearly from 2019 to 2022. Multilevel linear mixed models, fitted separately for boys and girls, were used to model the individual-level trends over time in centile score for each fitness test across 3 weight groups. Findings: Overall fitness levels decreased markedly across all weight categories between 2019 and 2020, with the largest decreases in Total Fitness Index observed in children with normal weight and overweight (-8.4 and -7.7 centiles for boys and -8.3 and -8.8 for girls, respectively, p < 0.001). While there was some recovery in the overall fitness level between 2020 and 2022, it remained much lower in 2022 compared to 2019 across most groups, apart from boys with obesity. Fitness components that had the largest impact on general fitness trends were cardiorespiratory fitness, lower body power, body core, and upper body strength. Interpretation: A severe decline in fitness that has not come close to returning to pre-pandemic levels in most population groups of youth begs for urgent population-wide initiatives that will provide additional opportunities for physical activity to youth. Among vulnerable groups, girls with overweight and obesity deserve a special focus of these policies. Funding: Horizon 2020 (Grant no. 774548), Slovenian National Research Agency (Grant no. P5-0142), Croatian Science Foundation (Grant no. DOK-2020-01-3728).

Secular trends in skill-related physical fitness among Slovenian children and adolescents from 1983 to 2014.

It is vital from the public health and educational perspective to be familiar with changes in the fitness levels of individuals and populations since fitness is associated with several health outcomes and cognition. Skill-related physical fitness refers to performance in sports or occupation and is associated with motor skill performance. The aim of the present study was to examine secular trends in skill-related physical fitness of 16 678 participants in four youth generations of Slovenian children and adolescents in years 1983 (n = 3128), 1993/94 (n = 3413), 2003/04 (n = 5497), and 2013/14 (n = 4640). Using repeated cross-sectional design, we observed fitness level of all participants divided into three age groups: 6-10, 11-14, and 15-19 years. Skill-related physical performance was measured with seven fitness tests for speed, coordination, balance, and flexibility. Analysis of covariance was used to compare differences in fitness performance between decades in each age and sex group, adjusted for body height, body weight, and body mass index. Overall, large but inconsistent changes in coordination, a small improvement in speed, and a decline in flexibility were seen. The trends over the whole examined period were not linear throughout decades. Generally, positive trends were noticed in periods 1983-1993 (range 1.4%-17.9%; except flexibility) and 2003/04-2013/14 (range 0.2%-36.4%; except age group 15-19 years) while in the period 1993/94-2003/04 there are some particularities in secular trends according to individual components as well as age groups. In general, the secular trend showed a positive direction for both genders (p < 0.05), except for gross motor coordination, which demonstrated positive trends in 1993 and 2013 compared with a decade earlier (p < 0.05) and from 1983 to 2013/14, except for the youngest boys in 2003 and the youngest girls from 1993 to 2003 (p < 0.05). Our findings call for exercise programs aimed at improving speed and gross motor coordination in both sexes and all age groups, especially in the group of 15-19 years old.

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.

Physical fitness trajectories from childhood to adolescence in extremely preterm children: A longitudinal cohort study.

OBJECTIVE: Cohort studies on physical fitness (PF) in former extremely preterm children are scarce and yield conflicting results. Therefore, this study aimed to assess the effect of extremely preterm birth on PF in school-age with a focus on bronchopulmonary dysplasia (BPD). METHODS: Eighty school-aged children were enrolled in the longitudinal cohort study. Fifty were born extremely preterm (

Adequacy of energy and macronutrients intake in differently active slovenian adolescents.

OBJECTIVE: Evaluate the adequacy of energy/macronutrient intake in adolescents according to the Slovenian national recommendations adopted from the recommendations of the German Nutrition Society and to identify differences in energy/macronutrient intake between differently active adolescents. METHODS: Data on energy and macronutrient intake (24-hour dietary recall), physical activity (SHAPES questionnaire), and anthropometric characteristics (body mass and height) of adolescents were obtained on a representative sample of first-year secondary school students (average (SD) age: 15.3 (0.5) years; N = 341), who were included in the national survey The Analysis of Children's Development in Slovenia (ACDSi) in 2013/14. RESULTS: 75% of adolescents met the national recommendations for carbohydrates and proteins and 44% for fats, whereas only 10% of adolescents met the recommendations for energy intake. Energy/macronutrient intakes were significantly higher in vigorously physically active (VPA) boys compared to moderately (MPA) and less (LPA) physically active boys. No such differences were observed between girls of different physical activity levels. CONCLUSION: Adolescents need to be encouraged to meet their energy needs according to gender and physical activity (especially VPA girls) and to reach for higher quality foods in adequate macronutrient proportions.

Adult height prediction using the growth curve comparison method.

Understanding the growth pattern is important in view of child and adolescent development. Due to different tempo of growth and timing of adolescent growth spurt, individuals reach their adult height at different ages. Accurate models to assess the growth involve intrusive radiological methods whereas the predictive models based solely on height data are typically limited to percentiles and therefore rather inaccurate, especially during the onset of puberty. There is a need for more accurate non-invasive methods for height prediction that are easily applicable in the fields of sports and physical education, as well as in endocrinology. We developed a novel method, called Growth Curve Comparison (GCC), for height prediction, based on a large cohort of > 16,000 Slovenian schoolchildren followed yearly from ages 8 to 18. We compared the GCC method to the percentile method, linear regressor, decision tree regressor, and extreme gradient boosting. The GCC method outperformed the predictions of other methods over the entire age span both in boys and girls. The method was incorporated into a publicly available web application. We anticipate our method to be applicable also to other models predicting developmental outcomes of children and adolescents, such as for comparison of any developmental curves of anthropometric as well as fitness data. It can serve as a useful tool for assessment, planning, implementation, and monitoring of somatic and motor development of children and youth.

Effectiveness of a population-scaled, school-based physical activity intervention for the prevention of childhood obesity.

OBJECTIVE: The aim of this study was to examine the effectiveness of a real-world, population-scaled, school-based physical activity (PA) intervention that provided two to three additional physical education lessons per week to children aged 6 to 14 years in Slovenia. METHODS: More than 34,000 participants from over 200 schools were compared with a similar number of nonparticipants from the same schools. Generalized estimating equations were used to estimate the effects of differing levels of exposure to the intervention (i.e., from 1-5 years) on BMI in children with normal weight, overweight, or obesity at baseline. RESULTS: BMI was lower in the intervention group, irrespective of participation duration or baseline weight status. The difference in BMI increased with the program duration, with maximal effects being seen after 3 to 4 years of participation, and was consistently larger for children with obesity (peaking at 1.4 kg/m2 [95% CI: 1.0-1.9] for girls with obesity and peaking at 0.9 kg/m2 [95% CI: 0.6-1.3] for boys with obesity). The program started to become effective at reversing obesity after 3 years, whereas the lowest numbers needed to treat (NNTs) were observed after 5 years (NNTs = 17 for girls and 12 for boys). CONCLUSIONS: The population-scaled, school-based PA intervention was effective in preventing and treating obesity. The effects were the greatest in children initially presenting with obesity, such that the program was able to benefit children needing support the most.

European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network.

OBJECTIVES: (1) To develop reference values for health-related fitness in European children and adolescents aged 6-18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. METHODS: This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test-retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. RESULTS: A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). CONCLUSION: This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe.

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

ABSTRACT: Blagus, R, Jurak, G, Starc, G, and Leskosek, 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.

Correction: Grasgruber et al. Mapping the Mountains of Giants: Anthropometric Data from the Western Balkans Reveal a Nucleus of Extraordinary Physical Stature in Europe. Biology 2022, 11, 786.

Note: The authors apologize for the rather extensive text corrections [...].

SLOfit Lifelong: A model for leveraging citizen science to promote and maintain physical fitness and physical literacy across the lifespan.

SLOfit Lifelong is a public health initiative which was created to upgrade a well-established, national physical fitness surveillance system for Slovenian schoolchildren that has been collecting annual fitness and health data for over three decades. The ultimate objective of creating SLOfit Lifelong was to build a modern societal infrastructure with the capacity and ability to detect future causal associations between childhood physical fitness trends and future health outcomes based on the lifelong surveillance of one's own fitness status. By instilling citizens with an ambition to test, understand, and follow-up their own physical fitness and health status (including related health risk factors), this initiative provides the technical support and expert feedback needed to engender greater individual control over understanding (and thus modulating), one's own physical fitness status as they progress into older adulthood. This perspective paper details the extensive approach taken to devise appropriate fitness test batteries for adults and older adults which can also relate to the student version of the original SLOfit test database, including establishing criterion health risk zones and a public approach to establish this national, citizen-driven health feedback framework. Through its sophisticated online web applications, social media, print media, and outreach workshops, SLOfit Lifelong provides the expert support for public health engagement by fostering positive lifelong physical literacy experiences an individual can enjoy across their aging journey.

Ringing the bell for quality P.E.: What are the realities of remote physical education?

BACKGROUND: To date, few data on the quality and quantity of online physical education (P.E.) during the COVID-19 pandemic have been published. We assessed activity in online classes and reported allocated curriculum time for P.E. in a multi-national sample of European children (6-18 years). METHODS: Data from two online surveys were analysed. A total of 8395 children were included in the first round (May-June 2020) and 24 302 in the second round (January-February 2021). RESULTS: Activity levels during P.E. classes were low in spring 2020, particularly among the youngest children and in certain countries. 27.9% of students did not do any online P.E. and 15.7% were hardly ever very active. Only 18.4% were always very active and 14.9% reported being very active quite often. In winter 2020, we observed a large variability in the allocated curriculum time for P.E. In many countries, this was lower than the compulsory requirements. Only 65.7% of respondents had the same number of P.E. lessons than before pandemic, while 23.8% had less P.E., and 6.8% claimed to have no P.E. lessons. Rates for no P.E. were especially high among secondary school students, and in large cities and megapolises. CONCLUSIONS: During the COVID-19 pandemic, European children were provided much less P.E. in quantity and quality than before the pandemic. Countermeasures are needed to ensure that these changes do not become permanent. Particular attention is needed in large cities and megapolises. The critical role of P.E. for students' health and development must be strengthened in the school system.

Work-related Musculoskeletal Disorders Among Physiotherapists and Physiotherapy Students in Croatia and their Association with Physical Fitness.

Introduction: Among physiotherapists, work-related musculoskeletal disorders (WMSDs) are the most common health problem. This study aimed to provide evidence for planning evidence-based health promotion programmes for ensuring and maintaining adequate physical fitness (PF) to decrease WMSDs among physiotherapists which would have started already during the study. Methods: A cross-sectional study involved the participation of a total of 100 physiotherapy students and 62 physiotherapists. Observed variables were prevalence of WMSDs in the last 12 months, lasting >3 days during physiotherapeutic activities and five PF components: body composition, cardiorespiratory and muscle endurance, muscle strength, and flexibility. A chi-square test and binary logistic regression were used as the main analytical methods. Results: Prevalence of WMSDs in physiotherapists was 63.9% (the most common locations: lower back, shoulders, neck), while in physiotherapy students it was 46.5% (the most common locations: lower back, neck, upper back) (p=0.031). Among the PF components, the results showed statistically significantly worse flexibility among students compared to physiotherapists (about two thirds of students had poor or very poor results of flexibility testing) (p=0.002) in comparison to physiotherapists. A statistically significant positive association between WMSDs and PF was observed only between knee pain and poor cardiorespiratory endurance (OR=4.03 with 95% CI 1.12-14.58; p=0.033). Conclusion: The study showed poor flexibility among students indicating that it is necessary to direct them to perform activities that will increase the extensibility of muscles. The awareness of this problem should be increased. A specific role should be played by staff involved in clinical practice.

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.

Mapping the Mountains of Giants: Anthropometric Data from the Western Balkans Reveal a Nucleus of Extraordinary Physical Stature in Europe.

The inhabitants of the Dinaric Alps (former Yugoslavia and Albania) have long been known as people of impressive body height, but after World War II, there was a critical lack of data related to this phenomenon. This anthropological synthesis includes the measurements of 47,158 individuals (24,642 males and 22,516 females) from the period 2010−2018 and describes detailed regional differences in male stature in the Western Balkans. According to these data, young men from Montenegro (182.9 cm) are currently the tallest 18-year-olds in the world, surpassing their Dutch peers (182.4 cm), and 18-year-old boys from Dalmatia are even taller (183.7 cm) at a regional level. A continuous belt of extraordinary height means (>184 cm) stretches from the Adriatic coast of Dalmatia through Herzegovina to the central part of Montenegro. This article summarizes all the key socio-economic, nutritional, and genetic data, and offers possible explanations for this anthropological phenomenon. Since the remarkable height of the Dinaric populations cannot be connected with any commonly known environmental factor, the most probable hypothesis is genetic and links these physical characteristics with the local founder effect of Y haplogroup I-M170. Furthermore, given that both the level of socio-economic development and dietary protein quality are still sub-optimal, the local upward trend in body height has the potential to continue in the future.

Can Primary School Mathematics Performance Be Predicted by Longitudinal Changes in Physical Fitness and Activity Indicators?

OBJECTIVE: To determine to what extent physical fitness indicators and/or moderate to vigorous physical activity (MVPA) may account for final mathematics academic performance (APmath) awarded at the end of primary school. METHODS: School-aged youth were sampled in a repeated-measures, longitudinal design in Grade 6 (∼11 years), and again in Grade 9 (∼14 years). The youth (N = 231, 111 girls) completed a fitness test battery consisting of: flamingo balance test, standing long jump, backward obstacle course, plate tapping, sit ups, sit and reach, handgrip, and 20-m shuttle run. APmath scores were obtained for all children at the end of Grade 5, end of Grade 8, and end of Grade 9 (their final year of primary school). In a sub-sample of Grade 6 youth (N = 50, 29 girls), MVPA was measured objectively via SenseWear Pro Armbands (MVPAOB) for seven consecutive days, with measurements repeated in Grade 9. RESULTS: Math scores decreased from Grade 6 to 9 for both boys and girls (95%CI: -0.89 to -0.53, p < 0.001). MVPAOB was reduced by ∼45.7 min (-33%) from Grade 6 to 9 (p < 0.01). Significant main and interaction effects are noted for each fitness indicator (p < 0.05). A backward stepwise multiple regression analysis determined significant shared variance in final APmath grade to the change scores from Grade 6 to Grade 9 in: ΔAPmath, Δbackward obstacle course, Δsit and reach, and Δsit-ups [R 2 = 0.494, F(4,180) = 43.67, p < 0.0001]. A second regression was performed only for the youth who completed MVPAOB measurements. In this sub-sample, MVPAOB did not significantly contribute to the model. CONCLUSION: Longitudinal changes in youth fitness and their delta change in APmath score accounted for 49.4% of the variance in the final math grade awarded at the end of Grade 9. Aerobic power, upper body strength, and muscular endurance share more common variance to final math grade in boys, whereas whole-body coordination was the more relevant index in girls; this finding suggests that future research exploring the relationship of AP and PF should not be limited to cardiorespiratory fitness, instead encompassing muscular and neuro-muscular components of PF.

Physical activity, screen time and the COVID-19 school closures in Europe - An observational study in 10 countries.

To date, few data on how the COVID-19 pandemic and restrictions affected children's physical activity in Europe have been published. This study examined the prevalence and correlates of physical activity and screen time from a large sample of European children during the COVID-19 pandemic to inform strategies and provide adequate mitigation measures. An online survey was conducted using convenience sampling from 15 May to 22 June, 2020. Parents were eligible if they resided in one of the survey countries and their children aged 6-18 years. 8395 children were included (median age [IQR], 13 [10-15] years; 47% boys; 57.6% urban residents; 15.5% in self-isolation). Approximately two-thirds followed structured routines (66.4% [95%CI, 65.4-67.4]), and more than half were active during online P.E. (56.6% [95%CI, 55.5-57.6]). 19.0% (95%CI, 18.2-19.9) met the WHO Global physical activity recommendation. Total screen time in excess of 2 h/day was highly prevalent (weekdays: 69.5% [95%CI, 68.5-70.5]; weekend: 63.8% [95%CI, 62.7-64.8]). Playing outdoors more than 2 h/day, following a daily routine and being active in online P.E. increased the odds of healthy levels of physical activity and screen time, particularly in mildly affected countries. In severely affected countries, online P.E. contributed most to meet screen time recommendation, whereas outdoor play was most important for adequate physical activity. Promoting safe and responsible outdoor activities, safeguarding P.E. lessons during distance learning and setting pre-planned, consistent daily routines are important in helping children maintain healthy active lifestyle in pandemic situation. These factors should be prioritised by policymakers, schools and parents. HighlightsTo our knowledge, our data provide the first multi-national estimates on physical activity and total screen time in European children roughly two months after COVID-19 was declared a global pandemic.Only 1 in 5 children met the WHO Global physical activity recommendations.Under pandemic conditions, parents should set pre-planned, consistent daily routines and integrate at least 2-hours outdoor activities into the daily schedule, preferable on each day. Schools should make P.E. lessons a priority. Decision makers should mandate online P.E. be delivered by schools during distance learning. Closing outdoor facilities for PA should be considered only as the last resort during lockdowns.

The Effect of Pandemic Movement Restriction Policies on Children's Physical Fitness, Activity, Screen Time, and Sleep.

Background: The negative impact of isolation, confinement, and physical (in)activity due to pandemic movement restriction has been well-documented over the past year, but less is known on the impact of these policies on children's physical fitness. This study was designed to determine the effects of pandemic movement restriction policies on the 24-hour movement behavior (24-HMB) of children, and whether any alterations are reflected in worsening physical fitness outcomes determined via direct testing. Methods: A two-phase, repeated-measures study with matched controls was conducted. Phase One: N = 62 schoolchildren (N = 31 female) completed self-assessment questionnaires on 24-HMB in October 2018 (pre-pandemic) and again in April 2020, at the height of movement restrictions enacted in response to the COVID-19 pandemic first wave. Phase Two: physical fitness of the original N = 62 children were determined directly pre- and post-isolation using an eight-component standardized fitness test battery and compared to N = 62 control children who were matched for age, sex, school region, and fitness centile scores. Results: During lockdown (total duration: 63 days), moderate-to-vigorous physical activity (MVPA) decreased by ~46 min per day, screen time demonstrated a significant interaction effect, such that kids reported spending less recreational screen time on weekends during lockdown compared to no restriction, and sleep duration was consistently lower (95% CI: -104.1 to -45.5 min, p < 0.001). No interaction effect was present for direct fitness indicators, including: hand tapping (reaction time), standing broad jump, polygon backward obstacle course (coordination), sit-ups, stand-and-reach, bent-arm hang, 60-m, and 600-m run (p ≥ 0.05) although significant main effects are noted for both sexes. Conclusion: Initial changes in 24-HMB did not translate to reductions in physical fitness per se, likely due to the high initial fitness levels of the children. Further work is needed to confirm whether longer or repeated movement restrictions exacerbate initial negative 24-HMB trends, especially for children who are less fit when restrictions are initiated, prolonged, or repeated.