[Skip to Content]
[Skip to Content Landing]

Association of COVID-19 Mitigation Measures With Changes in Cardiorespiratory Fitness and Body Mass Index Among Children Aged 7 to 10 Years in Austria

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME
Key Points

Question  Were COVID-19 mitigation measures associated with changes in cardiorespiratory fitness measures and body mass index among primary schoolchildren in Austria?

Findings  In this cohort study of 764 primary schoolchildren aged 7 to 10 years, COVID-19 mitigation measures were associated with substantial reductions in cardiorespiratory fitness measures and increases in body mass index SD scores and the proportion of children with overweight or obesity.

Meaning  The findings suggest that collaborative efforts are needed to improve children’s health and fitness to prevent long-term negative health outcomes.


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 Relevance  In 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.

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Accepted for Publication: June 12, 2021.

Published: August 26, 2021. doi:10.1001/jamanetworkopen.2021.21675

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Jarnig G et al. JAMA Network Open.

Corresponding Author: Gerald Jarnig, MSc, Institute of Human Movement Science, Sport and Health, University of Graz, Mozartgasse 14, 8010 Graz, Austria (gerald.jarnig@gmx.at).

Author Contributions: Messrs Jarnig and Jaunig contributed equally to this work. Messrs Jarnig and Jaunig had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Jarnig, van Poppel.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Jarnig, Jaunig.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Jarnig, Jaunig.

Obtained funding: Jarnig.

Administrative, technical, or material support: Jarnig.

Supervision: van Poppel.

Conflict of Interest Disclosures: Mr Jarnig reported receiving grants from the Austrian Federal Ministry for Arts, Culture, Civil Service and Sport during the conduct of the study. No other disclosures were reported.

Funding/Support: This study was funded by grant GZ205.410/0014-II/B/5/2018 (Mr Jarnig) from the Austrian Federal Ministry for Arts, Culture, Civil Service and Sport. The University of Graz funded open access publishing.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: We thank all participants and their guardians and the trainers and staff who assisted with this study. Wolfgang Modritz (Nachwuchsmodell, Austria) initiated the study; Rodrigo A. Lima, PhD (University of Graz, Austria), and Dr Peter Hofmann (University of Graz, Austria) provided support in the conception phase; Dr Robert Klinglmair (Education Directorate of Carinthia, Austria) authorized assessments in schools; Mag. Christian Günter (Austrian Federal Ministry of Sport) and Mag. Hannes Wolf (Education Directorate of Carinthia, Austria) helped continue the assessments after the COVID-19 lockdown. None of the individuals listed were financially compensated.

Additional Information: The study was organized by Nachwuchsmodell Austria. The Austrian Working Group on Pediatric Endocrinology and Diabetics provided the calculations for the Austrian reference values for height SD scores and body mass index centile curves (ie, equicurves).

Moore  SA , Faulkner  G , Rhodes  RE ,  et al.  Impact of the COVID-19 virus outbreak on movement and play behaviours of Canadian children and youth: a national survey.   Int J Behav Nutr Phys Act. 2020;17(1):85. doi:10.1186/s12966-020-00987-8 PubMedGoogle ScholarCrossref
Pombo  A , Luz  C , Rodrigues  LP , Ferreira  C , Cordovil  R .  Correlates of children’s physical activity during the COVID-19 confinement in Portugal.   Public Health. 2020;189:14-19. doi:10.1016/j.puhe.2020.09.009 PubMedGoogle ScholarCrossref
Dunton  GF , Do  B , Wang  SD .  Early effects of the COVID-19 pandemic on physical activity and sedentary behavior in children living in the U.S.   BMC Public Health. 2020;20(1):1351. doi:10.1186/s12889-020-09429-3 PubMedGoogle ScholarCrossref
López-Bueno  R , López-Sánchez  GF , Casajús  JA ,  et al.  Health-related behaviors among school-aged children and adolescents during the Spanish COVID-19 confinement.   Front Pediatr. 2020;8:573. doi:10.3389/fped.2020.00573 PubMedGoogle ScholarCrossref
Pietrobelli  A , Pecoraro  L , Ferruzzi  A ,  et al.  Effects of COVID-19 lockdown on lifestyle behaviors in children with obesity living in Verona, Italy: a longitudinal study.   Obesity (Silver Spring). 2020;28(8):1382-1385. doi:10.1002/oby.22861 PubMedGoogle ScholarCrossref
Margaritis  I , Houdart  S , El Ouadrhiri  Y , Bigard  X , Vuillemin  A , Duché  P .  How to deal with COVID-19 epidemic-related lockdown physical inactivity and sedentary increase in youth? adaptation of Anses’ benchmarks.   Arch Public Health. 2020;78:52. doi:10.1186/s13690-020-00432-z PubMedGoogle ScholarCrossref
Ortega  FB , Ruiz  JR , Castillo  MJ , Sjöström  M .  Physical fitness in childhood and adolescence: a powerful marker of health.   Int J Obes (Lond). 2008;32(1):1-11. doi:10.1038/sj.ijo.0803774 PubMedGoogle ScholarCrossref
Mintjens  S , Menting  MD , Daams  JG , van Poppel  MNM , Roseboom  TJ , Gemke  RJBJ .  Cardiorespiratory fitness in childhood and adolescence affects future cardiovascular risk factors: a systematic review of longitudinal studies.   Sports Med. 2018;48(11):2577-2605. doi:10.1007/s40279-018-0974-5 PubMedGoogle ScholarCrossref
Umer  A , Kelley  GA , Cottrell  LE , Giacobbi  P  Jr , Innes  KE , Lilly  CL .  Childhood obesity and adult cardiovascular disease risk factors: a systematic review with meta-analysis.   BMC Public Health. 2017;17(1):683. doi:10.1186/s12889-017-4691-z PubMedGoogle ScholarCrossref
Freedman  DS , Khan  LK , Dietz  WH , Srinivasan  SR , Berenson  GS .  Relationship of childhood obesity to coronary heart disease risk factors in adulthood: the Bogalusa Heart Study.   Pediatrics. 2001;108(3):712-718. doi:10.1542/peds.108.3.712 PubMedGoogle ScholarCrossref
von Elm  E , Altman  DG , Egger  M , Pocock  SJ , Gøtzsche  PC , Vandenbroucke  JP ; STROBE Initiative.  The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies.   PLoS Med. 2007;4(10):e296. doi:10.1371/journal.pmed.0040296 PubMedGoogle Scholar
Republic of Austria. Legal Information System of the Republic of Austria, Federal Law Gazzette [State Law Gazzette]. Published February 12, 2021. Accessed February 12, 2021. https://www.ris.bka.gv.at/Bgbl-Auth/
Stemper  T , Bachmann  C , Diehlmann  K , Kemper  B.   DüMo Düsseldorfer Modell der Bewegungs-, Sport- und Talentförderung: 2003-2018: Konzept, Normwerte, Untersuchungsergebnisse. LIT; 2020.
Bös  K.   Deutscher Motorik-Test 6-18: (DMT 6-18): Manual und internetbasierte Auswertungssoftware. 2. Auflage. Feldhaus, Edition Czwalina; 2016.
Cole TJ, Green PJ. Smoothing reference centile curves:  the LMS method and penalized likelihood.   Stat Med. 1992;11:1305-1319. doi:10.1002/sim.4780111005PubMedGoogle Scholar
Cole  TJ , Lobstein  T .  Extended international (IOTF) body mass index cut-offs for thinness, overweight and obesity.   Pediatr Obes. 2012;7(4):284-294. doi:10.1111/j.2047-6310.2012.00064.x PubMedGoogle ScholarCrossref
Mayer  M , Gleiss  A , Häusler  G ,  et al.  Weight and body mass index (BMI): current data for Austrian boys and girls aged 4 to under 19 years.   Ann Hum Biol. 2015;42(1):45-55. doi:10.3109/03014460.2014.907444 PubMedGoogle ScholarCrossref
Gleiss  A , Lassi  M , Blümel  P ,  et al.  Austrian height and body proportion references for children aged 4 to under 19 years.   Ann Hum Biol. 2013;40(4):324-332. doi:10.3109/03014460.2013.776110 PubMedGoogle ScholarCrossref
de Onis  M , Onyango  AW , Borghi  E , Siyam  A , Nishida  C , Siekmann  J .  Development of a WHO growth reference for school-aged children and adolescents.   Bull World Health Organ. 2007;85(9):660-667. doi:10.2471/BLT.07.043497 PubMedGoogle ScholarCrossref
Hartley  HO .  The maximum F-ratio as a short-cut test for heterogeneity of variance.   Biometrika. 1950;37(3-4):308-312. doi:10.1093/biomet/37.3-4.308PubMedGoogle ScholarCrossref
Dayton  JD , Ford  K , Carroll  SJ , Flynn  PA , Kourtidou  S , Holzer  RJ .  The deconditioning effect of the COVID-19 pandemic on unaffected healthy children.   Pediatr Cardiol. 2021;42(3):554-559. doi:10.1007/s00246-020-02513-w PubMedGoogle ScholarCrossref
Dauty  M , Menu  P , Fouasson-Chailloux  A .  Effects of the COVID-19 confinement period on physical conditions in young elite soccer players.   J Sports Med Phys Fitness. 2020. doi:10.23736/S0022-4707.20.11669-4PubMedGoogle Scholar
Bingham  DD , Daly-Smith  A , Hall  J ,  et al.  COVID-19 lockdown: ethnic differences in children’s self-reported physical activity and the importance of leaving the home environment: a longitudinal and cross-sectional study from the Born in Bradford birth cohort study.  Preprint. Posted online March 3, 2021.  medRxiv. doi:10.1101/2021.02.26.21252543Google Scholar
Browne  NT , Snethen  JA , Greenberg  CS ,  et al.  When pandemics collide: the impact of COVID-19 on childhood obesity.   J Pediatr Nurs. 2021;56:90-98. doi:10.1016/j.pedn.2020.11.004 PubMedGoogle ScholarCrossref
Kovacs  VA , Starc  G , Brandes  M ,  et al.  Physical activity, screen time and the COVID-19 school closures in Europe—an observational study in 10 countries.   Eur J Sport Sci. 2021;1-10. doi:10.1080/17461391.2021.1897166 PubMedGoogle Scholar
Inchley  J , Currie  D , Budisavljevic  S ,  et al. Spotlight on adolescent health and well-being: findings from the 2017/2018 Health Behaviour in School-Aged Children (HBSC) Survey in Europe and Canada. World Health Organization. Regional Office for Europe. Accessed February 16, 2021. https://www.euro.who.int/en/health-topics/Life-stages/child-and-adolescent-health/health-behaviour-in-school-aged-children-hbsc/publications/2020/spotlight-on-adolescent-health-and-well-being.-findings-from-the-20172018-health-behaviour-in-school-aged-children-hbsc-survey-in-europe-and-canada.-international-report.-volume-2.-key-data
Mears  R , Salway  R , Sharp  D , Shield  JPH , Jago  R .  A longitudinal study investigating change in BMI z-score in primary school-aged children and the association of child BMI z-score with parent BMI.   BMC Public Health. 2020;20(1):1902. doi:10.1186/s12889-020-10001-2 PubMedGoogle ScholarCrossref
Kang  HM , Jeong  DC , Suh  BK , Ahn  MB .  The impact of the coronavirus disease-2019 pandemic on childhood obesity and vitamin D status.   J Korean Med Sci. 2021;36(3):e21. doi:10.3346/jkms.2021.36.e21 PubMedGoogle Scholar
Hale  T,  Angrist  N,  Goldszmidt  R ,  et al.  A global panel database of pandemic policies (Oxford COVID-19 Government Response Tracker).   Nat Hum Behav. 2021;5:529-538. Published February 12, 2021. Accessed February 12, 2021. https://www.bsg.ox.ac.uk/research/research-projects/coronavirus-government-response-trackerGoogle Scholar
Abarca-Gómez  L , Abdeen  ZA , Hamid  ZA ,  et al; NCD Risk Factor Collaboration (NCD-RisC).  Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults.   Lancet. 2017;390(10113):2627-2642. doi:10.1016/S0140-6736(17)32129-3 PubMedGoogle ScholarCrossref
AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

  • 1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
  • 1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
  • 1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
  • 1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
  • 1.00 credit toward the CME [and Self-Assessment requirements] of the American Board of Surgery’s Continuous Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.

Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
Want full access to the AMA Ed Hub?
After you sign up for AMA Membership, make sure you sign in or create a Physician account with the AMA in order to access all learning activities on the AMA Ed Hub
Buy this activity
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right

Name Your Search

Save Search
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience

Lookup An Activity


My Saved Searches

You currently have no searches saved.


My Saved Courses

You currently have no courses saved.