IMPORTANCE Previous studies have shown reductions in self-reported physical activity levels in children associated with implementation of COVID-19 mitigation measures, and data on objectively assessed health parameters are limited. OBJECTIVE To examine the association of COVID-19 mitigation measures with changes in cardiorespiratory fitness (CRF) measures and body mass index (BMI) among primary schoolchildren. DESIGN, SETTING, AND PARTICIPANTS This cohort study included children aged 7 to 10 years from 12 randomly selected primary schools in urban and rural districts of Klagenfurt, Austria. Baseline CRF and BMI measurements were obtained in September 2019 before COVID-19 mitigation measures were implemented, and follow-up measurements were obtained in June and September 2020. EXPOSURES COVID-19 mitigation measures. MAIN OUTCOMES AND MEASURES Cardiorespiratory fitness was measured with a 6-minute endurance run test. Height and weight were objectively measured. Standard deviation scores were calculated for CRF and BMI. Changes over time were analyzed using analyses of variance. Secondary analyses were performed for subgroups stratified by sex. RESULTS A total of 764 children (383 girls [50.1%]) aged 7 to 10 years had all measurements completed. From September 2019 to September 2020, CRF SD scores changed by −1.06 (95% CI, −1.13 to −1.00), with a similar decrease in both boys and girls. Body mass index SD scores had increased by 0.12 (95% CI, 0.06-0.16) in June 2020 and by 0.16 (95% CI, 0.12-0.20) in September 2020 compared with September 2019. The increase in BMI SD scores (from September 2019 to September 2020) was greater among boys (0.23; 95% CI, 0.18-0.29) than among girls (0.09; 95% CI, 0.04-0.15). During the 1-year period, the percentage of children with overweight or obesity increased from 20.3% (155 children) to 24.1% (184 children) (difference, 3.8% [29 children]). CONCLUSIONS AND RELEVANCEIn this cohort study of children in Austria, COVID-19 mitigation measures were associated with decreases in CRF measures and increases in BMI. The findings suggest that collaborative efforts are needed to reverse these changes in children's health to prevent long-term negative health outcomes.

Background: The ramifications of COVID-19 restrictions might accelerate the already rising proportion of children with overweight or obesity. Objectives: To assess the association between COVID-19 restrictions and changes in body mass index (BMI) and the proportion of children with overweight or obesity. Methods: Cohort study with baseline measurements in September 2019 (prior to COVID-19 restrictions) and follow-up in June 2020, September 2020, and March 2021 at 12 primary schools in Austria. The height and weight of 738 children aged 7 to 10 years were measured and age-and sex-specific national and international standardized values were calculated. Changes over time were analysed by analysis of variance. Results: Mean BMI IOTF standard deviation scores (SDS) increased by 0.24 (95% CI, 0.21-0.28) between September 2019 and March 2021. The proportion of children with overweight or obesity increased from 20.7% to 26.2% during this period (p < 0.001) using national reference values-EQUI BMI AUT -comparable results were observed. Simultaneously, the height AUT SDS increased by 0.06 (95% CI, 0.05-0.08) with a larger increase in girls (+0.11; p < 0.001) than in boys (+0.03; p = 0.19). Conclusions: COVID-19 restrictions were associated with accelerated increases in mean BMI and the proportion of children with overweight or obesity. The increase in height SDS in girls calls for further investigations.

The COVID-19-related closing of schools and sport facilities resulted in major changes to daily routines worldwide. It was the aim of this study to investigate the impact of COVID-19-related mitigation measures on the health and fitness status of primary school children in Austria. Seven hundred and eight primary school children (7–10 years old) participated in the longitudinal study. Data on height, weight, waist circumference, and fitness were collected before (September 2019) and during the course of the COVID-19 pandemic (20 June, 20 September, 21 March, 21 June). A significant increase in EQUI BMIAUT (ⴄp2 = 0.087) and significant changes (ⴄp2 = 0.355) in waist circumference were found. Cardiorespiratory endurance (ⴄp2 = 0.440) and action speed (ⴄp2 = 0.221) decreased dramatically following lockdowns/school closures. In contrast, muscle strength showed no significant changes. The COVID-19-related mitigation measures intended to contain a communicable disease resulted in an acceleration of the pre-existing pandemic of overweight and obesity. The adverse combination of increasing BMI and the loss of physical fitness is likely to result in long-term negative effects on the health status of growing and developing individuals. Health professionals should therefore not only support further longitudinal observations of this “non-communicable disease” but also support intervention programs to reverse this worrying side-effect of COVID-19-associated containment policies.

Monitoring of anthropometric and physical fitness parameters in primary school children is important for the prevention of future health problems. Many of the existing test batteries that are useful for monitoring require expensive test materials, specialized test administrators, and a lot of space. This limits the usefulness of such tests for widespread use. The aim of this pilot study was to design and evaluate monitoring tools for anthropometrics and physical fitness tests in primary schools, called AUT FIT. The test battery consists of height, weight, and waist circumference measurement and eight fitness tests (6 min run, V sit-and-reach, jumping sideways, standing long jump, medicine ball throw, 4 × 10 m shuttle run, ruler drop, single leg stand). Data of 821 children aged 7 to 10 years were gathered. Most AUT FIT tests showed excellent test–retest and interrater reliability and were easy to implement. Criterion-related validity was evident by a strong correlation between physical education teacher rankings and rank scores for motor fitness. Nationwide implementation in the Austrian school system could be an important component for monitoring and improving the health and fitness of primary school children.

The ongoing COVID-19 pandemic not only impacted the health of school children directly through SARS-CoV-2 infections, but the associated closures of schools and sports facilities also resulted in long-term negative side effects. The aim of this study was to investigate the effects of COVID-19-related mitigation measures on the health and fitness status of primary school children in Austria. A total of 303 primary school children participated in the longitudinal study. Data on height, weight, and fitness were collected before the COVID-19 pandemic (September 2019) and at one-year intervals (September 2020 and September 2021) during the course of the pandemic. In the first year, from September 2019 to September 2020, there were alarming increases in body mass index (BMI) standard deviation scores (SDSs) (from 0.32 to 0.49) and dramatic decreases in both cardiorespiratory endurance (CRE) (from 0.49 to −0.43) and action speed (from −0.31 to −0.64). In the second year (September 2020 to September 2021), the BMI scores stabilized, and improvements in CRE were observed, especially in the subgroup of children who were members of sports clubs. In the future, more initiatives and projects, in addition to sports club activities, should be started and expanded, particularly in schools, to specifically counteract the observed health damage and, thus, have a positive effect on the development of all children, especially those without sports club membership.