{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T11:08:17Z","timestamp":1789643297678,"version":"4.0.0"},"reference-count":107,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,4,2]],"date-time":"2025-04-02T00:00:00Z","timestamp":1743552000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,4,2]],"date-time":"2025-04-02T00:00:00Z","timestamp":1743552000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100009828","name":"Universit\u00e4t Erfurt","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100009828","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Physical fitness (PF) is a vital health indicator, but many children do not meet the WHO physical activity guidelines. Low PF in children raises the risk of non-communicable diseases (NCDs) and negatively impacts their quality of life, a situation amplified during the COVID-19 pandemic. This study uses data from 38,084 German third-graders (7.8 to 9.4 years) across seven cohorts (school years 2017\/18\u20132023\/24) who participated in a statewide fitness evaluation program in the Federal State of Thuringia. We aimed to examine age, sex, and pandemic effects on endurance (6-minute run), coordination (star run), speed (20-meter linear sprint), lower limb power (powerLOW; standing long jump), upper limb power (powerUP; ball-push test), and static balance (one-legged stance with eyes closed). Data on height and mass was incorporated to clarify the task-specific impact of the body mass index (BMI) on performance. Our results corroborated reported age and sex effects, demonstrating linear development across the age range for all tests, and in static balance only, girls scored higher than boys. The relationship between BMI and task-specific performance revealed an inverted U-shaped function in weight-bearing tests (first four). Functions were steeper for boys than girls, implying a stronger BMI impact on performance for boys. BMI and age interaction suggest that being overweight may limit age-related performance benefits. Negative pandemic declines in endurance, coordination, powerLOW, and powerUP were more pronounced in \u201cfitter\u201d schools. In conclusion, task-specific performances should be interpreted considering age, sex, and body constitution. Pandemic-related performance declines emphasize the role of access to physical activity resources for all children.<\/jats:p>","DOI":"10.1038\/s41598-025-95461-5","type":"journal-article","created":{"date-parts":[[2025,4,4]],"date-time":"2025-04-04T13:38:07Z","timestamp":1743773887000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Impact of age, sex, body constitution, and the COVID-19 pandemic on the physical fitness of 38,084 German primary school children"],"prefix":"10.1038","volume":"15","author":[{"given":"Florian","family":"B\u00e4hr","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toni","family":"W\u00f6hrl","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paula","family":"Teich","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Puta","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reinhold","family":"Kliegl","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,4,2]]},"reference":[{"key":"95461_CR1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/sj.ijo.0803774","volume":"32","author":"FB Ortega","year":"2008","unstructured":"Ortega, F. B., Ruiz, J. R., Castillo, M. J. & Sj\u00f6str\u00f6m, M. Physical fitness in childhood and adolescence: a powerful marker of health. Int. J. Obes. (Lond). 32, 1\u201311. https:\/\/doi.org\/10.1038\/sj.ijo.0803774 (2008).","journal-title":"Int. J. Obes. (Lond)"},{"key":"95461_CR2","first-page":"126","volume":"100","author":"CJ Caspersen","year":"1985","unstructured":"Caspersen, C. J., Powell, K. E. & Christenson, G. M. Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research. Public. Health Rep. 100, 126\u2013131 (1985).","journal-title":"Public. Health Rep."},{"key":"95461_CR3","doi-asserted-by":"publisher","first-page":"e653","DOI":"10.1161\/cir.0000000000000461","volume":"134","author":"R Ross","year":"2016","unstructured":"Ross, R. et al. Importance of assessing cardiorespiratory fitness in clinical practice: A case for fitness as a clinical vital sign: A scientific statement from the American heart association. Circulation 134, e653\u2013e699. https:\/\/doi.org\/10.1161\/cir.0000000000000461 (2016).","journal-title":"Circulation"},{"key":"95461_CR4","doi-asserted-by":"publisher","first-page":"387","DOI":"10.1038\/ijo.2009.42","volume":"33","author":"MD Tsiros","year":"2009","unstructured":"Tsiros, M. D. et al. Health-related quality of life in obese children and adolescents. Int. J. Obes. (Lond). 33, 387\u2013400. https:\/\/doi.org\/10.1038\/ijo.2009.42 (2009).","journal-title":"Int. J. Obes. (Lond)"},{"key":"95461_CR5","doi-asserted-by":"publisher","first-page":"288","DOI":"10.1038\/s41574-019-0176-8","volume":"15","author":"M Bl\u00fcher","year":"2019","unstructured":"Bl\u00fcher, M. Obesity: global epidemiology and pathogenesis. Nat. Rev. Endocrinol. 15, 288\u2013298. https:\/\/doi.org\/10.1038\/s41574-019-0176-8 (2019).","journal-title":"Nat. Rev. Endocrinol."},{"key":"95461_CR6","doi-asserted-by":"publisher","first-page":"56","DOI":"10.1111\/obr.12316","volume":"17","author":"A Llewellyn","year":"2016","unstructured":"Llewellyn, A., Simmonds, M., Owen, C. G. & Woolacott, N. Childhood obesity as a predictor of morbidity in adulthood: a systematic review and meta-analysis. Obes. Rev. 17, 56\u201367. https:\/\/doi.org\/10.1111\/obr.12316 (2016).","journal-title":"Obes. Rev."},{"key":"95461_CR7","doi-asserted-by":"publisher","first-page":"1","DOI":"10.3310\/hta19430","volume":"19","author":"M Simmonds","year":"2015","unstructured":"Simmonds, M. et al. The use of measures of obesity in childhood for predicting obesity and the development of obesity-related diseases in adulthood: a systematic review and meta-analysis. Health Technol. Assess. 19, 1\u2013336. https:\/\/doi.org\/10.3310\/hta19430 (2015).","journal-title":"Health Technol. Assess."},{"key":"95461_CR8","doi-asserted-by":"publisher","first-page":"474","DOI":"10.1111\/j.1467-789X.2008.00475.x","volume":"9","author":"AS Singh","year":"2008","unstructured":"Singh, A. S., Mulder, C., Twisk, J. W., van Mechelen, W. & Chinapaw, M. J. Tracking of childhood overweight into adulthood: a systematic review of the literature. Obes. Rev. 9, 474\u2013488. https:\/\/doi.org\/10.1111\/j.1467-789X.2008.00475.x (2008).","journal-title":"Obes. Rev."},{"key":"95461_CR9","doi-asserted-by":"publisher","first-page":"474","DOI":"10.21037\/tp-21-507","volume":"11","author":"A Garc\u00eda-Hermoso","year":"2022","unstructured":"Garc\u00eda-Hermoso, A., Izquierdo, M. & Ram\u00edrez-V\u00e9lez, R. Tracking of physical fitness levels from childhood and adolescence to adulthood: a systematic review and meta-analysis. Transl Pediatr. 11, 474\u2013486. https:\/\/doi.org\/10.21037\/tp-21-507 (2022).","journal-title":"Transl Pediatr."},{"key":"95461_CR10","doi-asserted-by":"publisher","first-page":"1079","DOI":"10.1007\/s40279-019-01098-6","volume":"49","author":"A Garc\u00eda-Hermoso","year":"2019","unstructured":"Garc\u00eda-Hermoso, A., Ram\u00edrez-Campillo, R. & Izquierdo, M. Is muscular fitness associated with future health benefits in children and adolescents?? A systematic review and Meta-Analysis of longitudinal studies. Sports Med. 49, 1079\u20131094. https:\/\/doi.org\/10.1007\/s40279-019-01098-6 (2019).","journal-title":"Sports Med."},{"key":"95461_CR11","doi-asserted-by":"publisher","first-page":"952","DOI":"10.1001\/jamapediatrics.2020.2400","volume":"174","author":"A Garc\u00eda-Hermoso","year":"2020","unstructured":"Garc\u00eda-Hermoso, A., Ram\u00edrez-V\u00e9lez, R., Garc\u00eda-Alonso, Y., Alonso-Mart\u00ednez, A. M. & Izquierdo, M. Association of cardiorespiratory fitness levels during youth with health risk later in life: A systematic review and Meta-analysis. JAMA Pediatr. 174, 952\u2013960. https:\/\/doi.org\/10.1001\/jamapediatrics.2020.2400 (2020).","journal-title":"JAMA Pediatr."},{"key":"95461_CR12","doi-asserted-by":"publisher","first-page":"40","DOI":"10.1186\/1479-5868-7-40","volume":"7","author":"I Janssen","year":"2010","unstructured":"Janssen, I. & LeBlanc, A. G. Systematic review of the health benefits of physical activity and fitness in school-aged children and youth. Int. J. Behav. Nutr. Phys. Activity. 7, 40. https:\/\/doi.org\/10.1186\/1479-5868-7-40 (2010).","journal-title":"Int. J. Behav. Nutr. Phys. Activity"},{"key":"95461_CR13","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1016\/S2352-4642(19)30323-2","volume":"4","author":"R Guthold","year":"2020","unstructured":"Guthold, R., Stevens, G. A., Riley, L. M. & Bull, F. C. Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1\u00b76 million participants. Lancet Child. Adolesc. Health. 4, 23\u201335. https:\/\/doi.org\/10.1016\/S2352-4642(19)30323-2 (2020).","journal-title":"Lancet Child. Adolesc. Health"},{"key":"95461_CR14","doi-asserted-by":"publisher","first-page":"247","DOI":"10.1016\/S0140-6736(12)60646-1","volume":"380","author":"PC Hallal","year":"2012","unstructured":"Hallal, P. C. et al. Global physical activity levels: surveillance progress, pitfalls, and prospects. Lancet 380, 247\u2013257. https:\/\/doi.org\/10.1016\/S0140-6736(12)60646-1 (2012).","journal-title":"Lancet"},{"key":"95461_CR15","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1093\/eurpub\/ckv024","volume":"25","author":"M Kalman","year":"2015","unstructured":"Kalman, M. et al. Secular trends in moderate-to-vigorous physical activity in 32 countries from 2002 to 2010: a cross-national perspective. Eur. J. Pub. Health. 25, 37\u201340. https:\/\/doi.org\/10.1093\/eurpub\/ckv024 (2015).","journal-title":"Eur. J. Pub. Health"},{"key":"95461_CR16","doi-asserted-by":"publisher","first-page":"1451","DOI":"10.1136\/bjsports-2020-102955","volume":"54","author":"FC Bull","year":"2020","unstructured":"Bull, F. C. et al. World health organization 2020 guidelines on physical activity and sedentary behaviour. Br. J. Sports Med. 54, 1451. https:\/\/doi.org\/10.1136\/bjsports-2020-102955 (2020).","journal-title":"Br. J. Sports Med."},{"key":"95461_CR17","unstructured":"Krause, L., Anding, C. & Kamtsiuris, P. Vol. 59 (Robert Koch-Institut, Epidemiologie und Gesundheitsberichterstattung, (2016)."},{"key":"95461_CR18","doi-asserted-by":"publisher","first-page":"303","DOI":"10.1007\/s40279-020-01373-x","volume":"51","author":"T F\u00fchner","year":"2021","unstructured":"F\u00fchner, T., Kliegl, R., Arntz, F., Kriemler, S. & Granacher, U. An update on secular trends in physical fitness of children and adolescents from 1972 to 2015: A systematic review. Sports Med. 51, 303\u2013320. https:\/\/doi.org\/10.1007\/s40279-020-01373-x (2021).","journal-title":"Sports Med."},{"key":"95461_CR19","doi-asserted-by":"publisher","first-page":"766","DOI":"10.1016\/s0140-6736(14)60460-8","volume":"384","author":"M Ng","year":"2014","unstructured":"Ng, M. et al. Global, regional, and National prevalence of overweight and obesity in children and adults during 1980\u20132013: a systematic analysis for the global burden of disease study 2013. Lancet 384, 766\u2013781. https:\/\/doi.org\/10.1016\/s0140-6736(14)60460-8 (2014).","journal-title":"Lancet"},{"key":"95461_CR20","doi-asserted-by":"publisher","first-page":"478","DOI":"10.1136\/bjsports-2017-097982","volume":"53","author":"GR Tomkinson","year":"2019","unstructured":"Tomkinson, G. R., Lang, J. J. & Tremblay, M. S. Temporal trends in the cardiorespiratory fitness of children and adolescents representing 19 high-income and upper middle-income countries between 1981 and 2014. Br. J. Sports Med. 53, 478\u2013486. https:\/\/doi.org\/10.1136\/bjsports-2017-097982 (2019).","journal-title":"Br. J. Sports Med."},{"key":"95461_CR21","doi-asserted-by":"publisher","first-page":"1101","DOI":"10.1186\/s12889-015-2467-x","volume":"15","author":"AK Brettschneider","year":"2015","unstructured":"Brettschneider, A. K. et al. Updated prevalence rates of overweight and obesity in 11- to 17-year-old adolescents in Germany. Results from the telephone-based KiGGS wave 1 after correction for bias in self-reports. BMC Public. Health. 15, 1101. https:\/\/doi.org\/10.1186\/s12889-015-2467-x (2015).","journal-title":"BMC Public. Health"},{"key":"95461_CR22","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1007\/s00431-017-2861-8","volume":"176","author":"AK Brettschneider","year":"2017","unstructured":"Brettschneider, A. K., Schienkiewitz, A., Schmidt, S., Ellert, U. & Kurth, B. M. Updated prevalence rates of overweight and obesity in 4- to 10-year-old children in Germany. Results from the telephone-based KiGGS wave 1 after correction for bias in parental reports. Eur. J. Pediatr. 176, 547\u2013551. https:\/\/doi.org\/10.1007\/s00431-017-2861-8 (2017).","journal-title":"Eur. J. Pediatr."},{"key":"95461_CR23","doi-asserted-by":"publisher","first-page":"15","DOI":"10.17886\/rki-gbe-2018-022.2","volume":"3","author":"A Schienkiewitz","year":"2018","unstructured":"Schienkiewitz, A., Brettschneider, A. K., Damerow, S. & Rosario, A. S. Overweight and obesity among children and adolescents in Germany. Results of the cross-sectional KiGGS wave 2 study and trends. J. Health Monit. 3, 15\u201322. https:\/\/doi.org\/10.17886\/rki-gbe-2018-022.2 (2018).","journal-title":"J. Health Monit."},{"key":"95461_CR24","doi-asserted-by":"publisher","first-page":"100748","DOI":"10.1016\/j.lanepe.2023.100748","volume":"34","author":"A Martinko","year":"2023","unstructured":"Martinko, A., Sori\u0107, M., Jurak, G. & Starc, G. 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). Lancet Reg. Health Eur. 34, 100748. https:\/\/doi.org\/10.1016\/j.lanepe.2023.100748 (2023).","journal-title":"Lancet Reg. Health Eur."},{"key":"95461_CR25","doi-asserted-by":"crossref","first-page":"3963","DOI":"10.3390\/ijerph19073963","volume":"19","author":"M R\u00faa-Alonso","year":"2022","unstructured":"R\u00faa-Alonso, M. et al. Comparison of physical fitness profiles obtained before and during COVID-19 pandemic in two independent large samples of children and adolescents: DAFIS project. Int. J. Environ. Res. Public Health. 19, 3963 (2022).","journal-title":"Int. J. Environ. Res. Public Health"},{"key":"95461_CR26","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1186\/s40798-024-00687-8","volume":"10","author":"L Piesch","year":"2024","unstructured":"Piesch, L. et al. Effect of COVID-19 pandemic lockdowns on body mass index of primary school children from different socioeconomic backgrounds. Sports Med. - Open. 10, 20. https:\/\/doi.org\/10.1186\/s40798-024-00687-8 (2024).","journal-title":"Sports Med. - Open."},{"key":"95461_CR27","doi-asserted-by":"publisher","first-page":"1088","DOI":"10.1080\/02640414.2022.2047504","volume":"40","author":"L Basterfield","year":"2022","unstructured":"Basterfield, L. et al. Changes in children\u2019s physical fitness, BMI and health-related quality of life after the first 2020 COVID-19 lockdown in England: A longitudinal study. J. Sports Sci. 40, 1088\u20131096. https:\/\/doi.org\/10.1080\/02640414.2022.2047504 (2022).","journal-title":"J. Sports Sci."},{"key":"95461_CR28","doi-asserted-by":"publisher","first-page":"e12890","DOI":"10.1111\/ijpo.12890","volume":"17","author":"G Jarnig","year":"2022","unstructured":"Jarnig, G. et al. Acceleration in BMI gain following COVID-19 restrictions. A longitudinal study with 7- to 10-year-old primary school children. Pediatr. Obes. 17, e12890. https:\/\/doi.org\/10.1111\/ijpo.12890 (2022).","journal-title":"Pediatr. Obes."},{"key":"95461_CR29","doi-asserted-by":"publisher","first-page":"480","DOI":"10.3934\/publichealth.2023034","volume":"10","author":"C Drenowatz","year":"2023","unstructured":"Drenowatz, C., Ferrari, G., Greier, K., Chen, S. & Hinterk\u00f6rner, F. Physical fitness in Austrian elementary school children prior to and post-COVID-19. AIMS Public. Health. 10, 480\u2013495. https:\/\/doi.org\/10.3934\/publichealth.2023034 (2023).","journal-title":"AIMS Public. Health"},{"key":"95461_CR30","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph19084565","author":"S Wessely","year":"2022","unstructured":"Wessely, S. et al. Changes in motor performance and BMI of primary school children over Time-Influence of the COVID-19 confinement and social burden. Int. J. Environ. Res. Public. Health. https:\/\/doi.org\/10.3390\/ijerph19084565 (2022).","journal-title":"Int. J. Environ. Res. Public. Health"},{"key":"95461_CR31","doi-asserted-by":"publisher","first-page":"8937693","DOI":"10.1155\/2022\/8937693","volume":"2022","author":"S V Pajek","year":"2022","unstructured":"V Pajek, S. Impact of the COVID-19 pandemic on the motor development of schoolchildren in rural and urban environments. Biomed. Res. Int. 2022, 8937693. https:\/\/doi.org\/10.1155\/2022\/8937693 (2022).","journal-title":"Biomed. Res. Int."},{"key":"95461_CR32","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph182111099","author":"C Chambonni\u00e8re","year":"2021","unstructured":"Chambonni\u00e8re, C. et al. Adverse collateral effects of COVID-19 public health restrictions on physical fitness and cognitive performance in primary school children. Int. J. Environ. Res. Public. Health. 18 https:\/\/doi.org\/10.3390\/ijerph182111099 (2021).","journal-title":"Int. J. Environ. Res. Public. Health"},{"key":"95461_CR33","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph19159504","author":"T Eberhardt","year":"2022","unstructured":"Eberhardt, T., B\u00f6s, K. & Niessner, C. Changes in physical fitness during the COVID-19 pandemic in German children. Int. J. Environ. Res. Public. Health. https:\/\/doi.org\/10.3390\/ijerph19159504 (2022).","journal-title":"Int. J. Environ. Res. Public. Health"},{"key":"95461_CR34","doi-asserted-by":"publisher","DOI":"10.3390\/sports10030043","author":"G Jarnig","year":"2022","unstructured":"Jarnig, G., Kerbl, R. & van Poppel, M. N. M. The impact of COVID-19-Related mitigation measures on the health and fitness status of primary school children in Austria: A longitudinal study with data from 708 children measured before and during the ongoing COVID-19 pandemic. Sports (Basel). https:\/\/doi.org\/10.3390\/sports10030043 (2022).","journal-title":"Sports (Basel)"},{"key":"95461_CR35","doi-asserted-by":"publisher","unstructured":"Stojan, R. et al. Motor performance in children before, during and after COVID-19 pandemic and the role of socioeconomic background: A 10-year cohort study of 68,996 third grade children. (2023). https:\/\/doi.org\/10.31219\/osf.io\/6qxrm","DOI":"10.31219\/osf.io\/6qxrm"},{"key":"95461_CR36","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1186\/s40798-023-00624-1","volume":"9","author":"P Teich","year":"2023","unstructured":"Teich, P. et al. Covid pandemic effects on the physical fitness of primary school children: results of the German EMOTIKON project. Sports Med. - Open. 9, 77. https:\/\/doi.org\/10.1186\/s40798-023-00624-1 (2023).","journal-title":"Sports Med. - Open."},{"key":"95461_CR37","doi-asserted-by":"publisher","DOI":"10.3389\/fpubh.2021.644235","author":"G Jurak","year":"2021","unstructured":"Jurak, G. et al. A COVID-19 crisis in child physical fitness: creating a barometric tool of public health engagement for the Republic of Slovenia. Front. Public. Health. https:\/\/doi.org\/10.3389\/fpubh.2021.644235 (2021).","journal-title":"Front. Public. Health"},{"key":"95461_CR38","doi-asserted-by":"publisher","unstructured":"Teich, P. et al. Association of school social status with Covid pandemic related changes and post-pandemic rebounds of children\u2019s physical fitness. (2024). https:\/\/doi.org\/10.21203\/rs.3.rs-4997009\/v1","DOI":"10.21203\/rs.3.rs-4997009\/v1"},{"key":"95461_CR39","doi-asserted-by":"publisher","first-page":"1680","DOI":"10.1186\/s12889-022-14089-6","volume":"22","author":"G Chen","year":"2022","unstructured":"Chen, G., Chen, J., Liu, J., Hu, Y. & Liu, Y. Relationship between body mass index and physical fitness of children and adolescents in Xinjiang, China: a cross-sectional study. BMC Public. Health. 22, 1680. https:\/\/doi.org\/10.1186\/s12889-022-14089-6 (2022).","journal-title":"BMC Public. Health"},{"key":"95461_CR40","doi-asserted-by":"publisher","first-page":"635478","DOI":"10.3389\/fspor.2021.635478","volume":"3","author":"C Drenowatz","year":"2021","unstructured":"Drenowatz, C., Hinterk\u00f6rner, F. & Greier, K. Physical fitness and motor competence in upper Austrian elementary school Children-Study protocol and preliminary findings of a State-Wide fitness testing program. Front. Sports Act. Living. 3, 635478. https:\/\/doi.org\/10.3389\/fspor.2021.635478 (2021).","journal-title":"Front. Sports Act. Living"},{"key":"95461_CR41","doi-asserted-by":"publisher","first-page":"404","DOI":"10.3109\/17477160903497902","volume":"5","author":"YC Huang","year":"2010","unstructured":"Huang, Y. C. & Malina, R. M. Body mass index and individual physical fitness tests in Taiwanese youth aged 9\u201318 years. Int. J. Pediatr. Obes. 5, 404\u2013411. https:\/\/doi.org\/10.3109\/17477160903497902 (2010).","journal-title":"Int. J. Pediatr. Obes."},{"key":"95461_CR42","doi-asserted-by":"publisher","first-page":"406","DOI":"10.1080\/03014460.2018.1494306","volume":"45","author":"J Kwieci\u0144ski","year":"2018","unstructured":"Kwieci\u0144ski, J. et al. Non-linear relationships between the BMI and physical fitness in Polish adolescents. Ann. Hum. Biol. 45, 406\u2013413. https:\/\/doi.org\/10.1080\/03014460.2018.1494306 (2018).","journal-title":"Ann. Hum. Biol."},{"key":"95461_CR43","doi-asserted-by":"publisher","DOI":"10.1002\/ajhb.23035","author":"VP Lopes","year":"2017","unstructured":"Lopes, V. P. et al. Linear and nonlinear relationships between body mass index and physical fitness in Brazilian children and adolescents. Am. J. Hum. Biol. https:\/\/doi.org\/10.1002\/ajhb.23035 (2017).","journal-title":"Am. J. Hum. Biol."},{"key":"95461_CR44","doi-asserted-by":"publisher","first-page":"443","DOI":"10.1111\/cch.12557","volume":"44","author":"VP Lopes","year":"2018","unstructured":"Lopes, V. P., Malina, R. M., Maia, J. A. R. & Rodrigues, L. P. Body mass index and motor coordination: Non-linear relationships in children 6\u201310 years. Child. Care Health Dev. 44, 443\u2013451. https:\/\/doi.org\/10.1111\/cch.12557 (2018).","journal-title":"Child. Care Health Dev."},{"key":"95461_CR45","doi-asserted-by":"publisher","DOI":"10.3389\/fpubh.2022.1047501","author":"G Qin","year":"2022","unstructured":"Qin, G., Qin, Y. & Liu, B. Association between BMI and health-related physical fitness: A cross-sectional study in Chinese high school students. Front. Public. Health. https:\/\/doi.org\/10.3389\/fpubh.2022.1047501 (2022).","journal-title":"Front. Public. Health"},{"key":"95461_CR46","doi-asserted-by":"publisher","first-page":"173s","DOI":"10.1093\/ajcn\/70.1.173s","volume":"70","author":"MC Bellizzi","year":"1999","unstructured":"Bellizzi, M. C. & Dietz, W. H. Workshop on childhood obesity: summary of the discussion. Am. J. Clin. Nutr. 70, 173s\u2013175s. https:\/\/doi.org\/10.1093\/ajcn\/70.1.173s (1999).","journal-title":"Am. J. Clin. Nutr."},{"key":"95461_CR47","doi-asserted-by":"publisher","first-page":"1369","DOI":"10.1038\/s41390-024-03112-8","volume":"96","author":"AO Agbaje","year":"2024","unstructured":"Agbaje, A. O. Waist-circumference-to-height-ratio had better longitudinal agreement with DEXA-measured fat mass than BMI in 7237 children. Pediatr. Res. 96, 1369\u20131380. https:\/\/doi.org\/10.1038\/s41390-024-03112-8 (2024).","journal-title":"Pediatr. Res."},{"key":"95461_CR48","doi-asserted-by":"publisher","first-page":"718","DOI":"10.3945\/an.117.015446","volume":"8","author":"CAS Alves Junior","year":"2017","unstructured":"Alves Junior, C. A. S., Mocellin, M. C., Gon\u00e7alves, E. C. A., Silva, D. A. S. & Trindade, E. B. S. M. Anthropometric indicators as body fat discriminators in children and adolescents: A systematic review and Meta-Analysis. Adv. Nutr. 8, 718\u2013727. https:\/\/doi.org\/10.3945\/an.117.015446 (2017).","journal-title":"Adv. Nutr."},{"key":"95461_CR49","doi-asserted-by":"crossref","first-page":"512","DOI":"10.3390\/nu8080512","volume":"8","author":"N Martin-Calvo","year":"2016","unstructured":"Martin-Calvo, N., Moreno-Galarraga, L. & Martinez-Gonzalez, M. A. Association between body mass index, Waist-to-Height ratio and adiposity in children: A systematic review and Meta-Analysis. Nutrients 8, 512 (2016).","journal-title":"Nutrients"},{"key":"95461_CR50","doi-asserted-by":"publisher","first-page":"988","DOI":"10.1038\/sj.ijo.0803226","volume":"30","author":"HD McCarthy","year":"2006","unstructured":"McCarthy, H. D. & Ashwell, M. A study of central fatness using waist-to-height ratios in UK children and adolescents over two decades supports the simple message \u2013 \u2018keep your waist circumference to less than half your height\u2019. Int. J. Obes. 30, 988\u2013992. https:\/\/doi.org\/10.1038\/sj.ijo.0803226 (2006).","journal-title":"Int. J. Obes."},{"key":"95461_CR51","doi-asserted-by":"publisher","first-page":"366","DOI":"10.1016\/j.jpeds.2015.04.043","volume":"167","author":"MC Brault","year":"2015","unstructured":"Brault, M. C., Turcotte, O., Aim\u00e9, A., C\u00f4t\u00e9, M. & B\u00e9gin, C. Body mass index accuracy in preadolescents: can we trust Self-Report or should we seek parent report?? J. Pediatr. 167, 366\u2013371. https:\/\/doi.org\/10.1016\/j.jpeds.2015.04.043 (2015).","journal-title":"J. Pediatr."},{"key":"95461_CR52","doi-asserted-by":"publisher","first-page":"632","DOI":"10.3390\/ijerph9020632","volume":"9","author":"AK Brettschneider","year":"2012","unstructured":"Brettschneider, A. K., Ellert, U. & Schaffrath Rosario, A. Comparison of BMI derived from parent-reported height and weight with measured values: results from the German KiGGS study. Int. J. Environ. Res. Public. Health. 9, 632\u2013647. https:\/\/doi.org\/10.3390\/ijerph9020632 (2012).","journal-title":"Int. J. Environ. Res. Public. Health"},{"key":"95461_CR53","doi-asserted-by":"publisher","first-page":"52","DOI":"10.1542\/peds.106.1.52","volume":"106","author":"E Goodman","year":"2000","unstructured":"Goodman, E., Hinden, B. R. & Khandelwal, S. Accuracy of teen and parental reports of obesity and body mass index. Pediatrics 106, 52\u201358. https:\/\/doi.org\/10.1542\/peds.106.1.52 (2000).","journal-title":"Pediatrics"},{"key":"95461_CR54","doi-asserted-by":"publisher","first-page":"17566","DOI":"10.1038\/s41598-021-97000-4","volume":"11","author":"T F\u00fchner","year":"2021","unstructured":"F\u00fchner, T., Granacher, U., Golle, K. & Kliegl, R. Age and sex effects in physical fitness components of 108,295 third graders including 515 primary schools and 9 cohorts. Sci. Rep. 11, 17566. https:\/\/doi.org\/10.1038\/s41598-021-97000-4 (2021).","journal-title":"Sci. Rep."},{"key":"95461_CR55","first-page":"45","volume":"44","author":"TJ Cole","year":"1990","unstructured":"Cole, T. J. The LMS method for constructing normalized growth standards. Eur. J. Clin. Nutr. 44, 45\u201360 (1990).","journal-title":"Eur. J. Clin. Nutr."},{"key":"95461_CR56","doi-asserted-by":"publisher","first-page":"1305","DOI":"10.1002\/sim.4780111005","volume":"11","author":"TJ Cole","year":"1992","unstructured":"Cole, T. J. & Green, P. J. Smoothing reference centile curves: the LMS method and penalized likelihood. Stat. Med. 11, 1305\u20131319. https:\/\/doi.org\/10.1002\/sim.4780111005 (1992).","journal-title":"Stat. Med."},{"key":"95461_CR57","unstructured":"Flegal, K. M. & Cole, T. J. Construction of LMS parameters for the centers for disease control and prevention 2000 growth charts. Natl. Health Stat. Rep., 1\u20133 (2013)."},{"key":"95461_CR58","doi-asserted-by":"publisher","first-page":"2191","DOI":"10.1001\/jama.2013.281053","volume":"310","author":"World Medical Association","year":"2013","unstructured":"World Medical Association. World medical association declaration of Helsinki: ethical principles for medical research involving human subjects. Jama 310, 2191\u20132194. https:\/\/doi.org\/10.1001\/jama.2013.281053 (2013).","journal-title":"Jama"},{"key":"95461_CR59","doi-asserted-by":"publisher","first-page":"7801","DOI":"10.1038\/s41598-022-11710-x","volume":"12","author":"T F\u00fchner","year":"2022","unstructured":"F\u00fchner, T., Granacher, U., Golle, K. & Kliegl, R. Effect of timing of school enrollment on physical fitness in third graders. Sci. Rep. 12, 7801. https:\/\/doi.org\/10.1038\/s41598-022-11710-x (2022).","journal-title":"Sci. Rep."},{"key":"95461_CR60","doi-asserted-by":"publisher","first-page":"8788","DOI":"10.1038\/s41598-023-35727-y","volume":"13","author":"P Teich","year":"2023","unstructured":"Teich, P., F\u00fchner, T., Granacher, U. & Kliegl, R. Physical fitness of primary school children differs depending on their timing of school enrollment. Sci. Rep. 13, 8788. https:\/\/doi.org\/10.1038\/s41598-023-35727-y (2023).","journal-title":"Sci. Rep."},{"key":"95461_CR61","volume-title":"Deutscher Motorik Test 6\u201318 (DTM)","author":"K B\u00f6s","year":"2009","unstructured":"B\u00f6s, K. et al. Deutscher Motorik Test 6\u201318 (DTM) 1st edn, Vol. 186 (Czwalina, 2009).","edition":"1"},{"key":"95461_CR62","first-page":"351","volume":"62","author":"B von Haaren","year":"2011","unstructured":"von Haaren, B., H\u00e4rtel, S., Seidel, I., Schlenker, L. & B\u00f6s, K. Validity of a 6-min endurance run and a 20-m shuttle run in 9- to 11-year old children [Die Validit\u00e4t des 6-Minuten-Laufs und 20m Shuttle Runs bei 9- bis 11-j\u00e4hrigen Kindern]. Dtsch. Z. F\u00fcr Sportmedizin. 62, 351\u2013355 (2011).","journal-title":"Dtsch. Z. F\u00fcr Sportmedizin"},{"key":"95461_CR63","unstructured":"Schulz, S. The reliability of the star coordination run and the 1-kg medicine ball push-physical fitness tests used in the EMOTIKON-study. Univ. Potsdam (2013)."},{"key":"95461_CR64","doi-asserted-by":"publisher","first-page":"2277","DOI":"10.1519\/jsc.0000000000000864","volume":"29","author":"JR Fernandez-Santos","year":"2015","unstructured":"Fernandez-Santos, J. R., Ruiz, J. R., Cohen, D. D., Gonzalez-Montesinos, J. L. & Castro-Pi\u00f1ero, J. Reliability and validity of tests to assess Lower-Body muscular power in children. J. Strength. Cond Res. 29, 2277\u20132285. https:\/\/doi.org\/10.1519\/jsc.0000000000000864 (2015).","journal-title":"J. Strength. Cond Res."},{"key":"95461_CR65","first-page":"2277","volume":"2","author":"S Schulz","year":"2013","unstructured":"Schulz, S. Die reliabilit\u00e4t des sternlaufs und des medizinballsto\u00dfes Im EMOTIKON-Test [The reliability of the star-coordination-run test and the 1-kg medicine ball-push test: Physical fitness tests used in the EMOTIKON study]. Univ. Potsdam. 2, 2277\u20132285 (2013).","journal-title":"Univ. Potsdam"},{"key":"95461_CR66","unstructured":"Bormann, A. Wissenschaftliche Analyse im Rahmen der Implementierung des Einbeinstandtests in der Primarstufe im Land Branden\u2013burg (EMOTIKON\u2013Studie). \u00dcberpr\u00fcfung der Reliabilit\u00e4t und Normwertbildung [Scientific analysis as part of the implementation of the one\u2013legged\u2013stance test in primary school in the Federal State of Brandenburg, Germany (EMOTIKON study). Reliability and normative values]. \u00dcberpr\u00fcfung der Reliabilit\u00e4t und Normwertbildung [Scientific analysis as part of the implementation of the one-legged-stance test in primary school in the Federal State of Brandenburg, Germany (EMOTIKON study). Reliability and normative values].(University of Potsdam, 2016) (2016)."},{"key":"95461_CR67","doi-asserted-by":"publisher","first-page":"211","DOI":"10.1111\/j.2517-6161.1964.tb00553.x","volume":"26","author":"GEP Box","year":"1964","unstructured":"Box, G. E. P. & Cox, D. R. An analysis of transformations. J. Roy. Stat. Soc.: Ser. B (Methodol.). 26, 211\u2013243. https:\/\/doi.org\/10.1111\/j.2517-6161.1964.tb00553.x (1964).","journal-title":"J. Roy. Stat. Soc.: Ser. B (Methodol.)"},{"key":"95461_CR68","unstructured":"Vogel, M. Data and Methods Around Reference Values in Pediatrics. R package version 0.8.0. (2022)."},{"key":"95461_CR69","doi-asserted-by":"publisher","DOI":"10.1007\/s00103-012-1486-3","author":"H H\u00f6lling","year":"2012","unstructured":"H\u00f6lling, H. et al. Die KiGGS-Studie: bundesweit repr\u00e4sentative L\u00e4ngs- und querschnittstudie Zur gesundheit von kindern und Jugendlichen Im Rahmen des gesundheitsmonitorings am Robert Koch-Institut. Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz. https:\/\/doi.org\/10.1007\/s00103-012-1486-3 (2012).","journal-title":"Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz"},{"key":"95461_CR70","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1257\/jel.48.2.281","volume":"48","author":"DS Lee","year":"2010","unstructured":"Lee, D. S. & Lemieux, T. Regression discontinuity designs in economics. J. Econ. Lit. 48, 281\u2013355 (2010).","journal-title":"J. Econ. Lit."},{"key":"95461_CR71","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1353\/obs.2017.0000","volume":"3","author":"DL Thistlewaite","year":"2017","unstructured":"Thistlewaite, D. L. & Campbell, D. T. Regression-discontinuity analysis: an alternative to the ex-post facto experiment. Observational Stud. 3, 119\u2013128 (2017).","journal-title":"Observational Stud."},{"key":"95461_CR72","unstructured":"Bates, D., Kliegl, R., Vasishth, S. & Baayen, H. Parsimonious mixed models. arXiv preprint arXiv:1506.04967 (2015)."},{"key":"95461_CR73","doi-asserted-by":"crossref","first-page":"1882","DOI":"10.3758\/s13428-017-0956-9","volume":"50","author":"H Matuschek","year":"2018","unstructured":"Matuschek, H. & Kliegl, R. On the ambiguity of interaction and nonlinear main effects in a regime of dependent covariates. Behav. Res. Methods. 50, 1882\u20131894 (2018).","journal-title":"Behav. Res. Methods"},{"key":"95461_CR74","doi-asserted-by":"publisher","DOI":"10.3389\/fpsyg.2010.00238","author":"R Kliegl","year":"2011","unstructured":"Kliegl, R., Wei, P., Dambacher, M., Yan, M. & Zhou, X. Experimental effects and individual differences in linear mixed models: estimating the relationship between Spatial, object, and attraction effects in visual attention. Front. Psychol. https:\/\/doi.org\/10.3389\/fpsyg.2010.00238 (2011).","journal-title":"Front. Psychol."},{"key":"95461_CR75","doi-asserted-by":"publisher","unstructured":"Douglas Bates, P. A., Kleinschmidt, D., Calder\u00f3n, J. B. S., Zhan, L., Noack, A., Bouchet-Valat, M., Arslan, A., Kelman, T., Baldassari, A., Ehinger, B., Karrasch, D., Saba, E., Quinn, J., Hatherly, M., Piibeleht, M., Mogensen, P. K., Babayan, S., Holy, T., Nazarathy, Y. JuliaStats\/MixedModels.jl v4.26.1. https:\/\/doi.org\/10.5281\/zenodo.13864525 (2011).","DOI":"10.5281\/zenodo.13864525"},{"key":"95461_CR76","doi-asserted-by":"publisher","unstructured":"Alday, P. palday\/MixedModelsExtras.jl: v2.1.1. (2024). https:\/\/doi.org\/10.5281\/zenodo.10569543","DOI":"10.5281\/zenodo.10569543"},{"key":"95461_CR77","doi-asserted-by":"publisher","unstructured":"Alday, P. & Bates, D. palday\/MixedModelsMakie.jl: v0.3.24. (2023). https:\/\/doi.org\/10.5281\/zenodo.8125544","DOI":"10.5281\/zenodo.8125544"},{"key":"95461_CR78","doi-asserted-by":"publisher","first-page":"65","DOI":"10.1137\/141000671","volume":"59","author":"J Bezanson","year":"2017","unstructured":"Bezanson, J., Edelman, A., Karpinski, S., Shah, V. B. & Julia A fresh approach to numerical computing. SIAM Rev. 59, 65\u201398. https:\/\/doi.org\/10.1137\/141000671 (2017).","journal-title":"SIAM Rev."},{"key":"95461_CR79","doi-asserted-by":"crossref","first-page":"1686","DOI":"10.21105\/joss.01686","volume":"4","author":"H Wickham","year":"2019","unstructured":"Wickham, H. et al. Welcome to the tidyverse. J. Open. Source Softw. 4, 1686 (2019).","journal-title":"J. Open. Source Softw."},{"key":"95461_CR80","doi-asserted-by":"crossref","unstructured":"L\u00fcdecke, D. et al. easystats: Framework for Easy Statistical Modeling, Visualization, and Reporting. CRAN (2022).","DOI":"10.32614\/CRAN.package.easystats"},{"key":"95461_CR81","unstructured":"R Core Team. R: A Language and Environment for Statistical Computing. (2023)."},{"key":"95461_CR82","unstructured":"RStudio Team. RStudio: Integrated Development Environment for R. (2023)."},{"key":"95461_CR83","doi-asserted-by":"publisher","first-page":"134","DOI":"10.1177\/2372732217749254","volume":"5","author":"JL Rodgers","year":"2018","unstructured":"Rodgers, J. L. & Shrout, P. E. Psychology\u2019s replication crisis as scientific opportunity: A pr\u00e9cis for policymakers. Policy Insights Behav. Brain Sci. 5, 134\u2013141. https:\/\/doi.org\/10.1177\/2372732217749254 (2018).","journal-title":"Policy Insights Behav. Brain Sci."},{"key":"95461_CR84","doi-asserted-by":"publisher","first-page":"174","DOI":"10.1123\/pes.12.2.174","volume":"12","author":"G Beunen","year":"2000","unstructured":"Beunen, G. & Thomis, M. Muscular strength development in children and adolescents. Pediatr. Exerc. Sci. 12, 174\u2013197. https:\/\/doi.org\/10.1123\/pes.12.2.174 (2000).","journal-title":"Pediatr. Exerc. Sci."},{"key":"95461_CR85","doi-asserted-by":"publisher","first-page":"e0142393","DOI":"10.1371\/journal.pone.0142393","volume":"10","author":"K Golle","year":"2015","unstructured":"Golle, K., Muehlbauer, T., Wick, D. & Granacher, U. Physical fitness percentiles of German children aged 9\u201312 years: findings from a longitudinal study. PLoS One. 10, e0142393. https:\/\/doi.org\/10.1371\/journal.pone.0142393 (2015).","journal-title":"PLoS One"},{"key":"95461_CR86","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1080\/09751270.2010.11885146","volume":"2","author":"S Kirchengast","year":"2010","unstructured":"Kirchengast, S. Gender differences in body composition from childhood to old age: an evolutionary point of view. J. Life Sci. 2, 1\u201310. https:\/\/doi.org\/10.1080\/09751270.2010.11885146 (2010).","journal-title":"J. Life Sci."},{"key":"95461_CR87","doi-asserted-by":"publisher","first-page":"415","DOI":"10.1016\/j.beem.2007.04.007","volume":"21","author":"JC Wells","year":"2007","unstructured":"Wells, J. C. Sexual dimorphism of body composition. Best Pract. Res. Clin. Endocrinol. Metab. 21, 415\u2013430. https:\/\/doi.org\/10.1016\/j.beem.2007.04.007 (2007).","journal-title":"Best Pract. Res. Clin. Endocrinol. Metab."},{"key":"95461_CR88","doi-asserted-by":"publisher","first-page":"612","DOI":"10.1136\/adc.2005.085522","volume":"91","author":"JCK Wells","year":"2006","unstructured":"Wells, J. C. K. & Fewtrell, M. S. Measuring body composition. Arch. Dis. Child. 91, 612\u2013617. https:\/\/doi.org\/10.1136\/adc.2005.085522 (2006).","journal-title":"Arch. Dis. Child."},{"key":"95461_CR89","doi-asserted-by":"publisher","first-page":"220","DOI":"10.1123\/pes.21.2.220","volume":"21","author":"A Nevill","year":"2009","unstructured":"Nevill, A., Tsiotra, G., Tsimeas, P. & Koutedakis, Y. Allometric associations between body size, shape, and physical performance of Greek children. Pediatr. Exerc. Sci. 21, 220\u2013232. https:\/\/doi.org\/10.1123\/pes.21.2.220 (2009).","journal-title":"Pediatr. Exerc. Sci."},{"key":"95461_CR90","doi-asserted-by":"publisher","first-page":"e155","DOI":"10.1111\/sms.12231","volume":"25","author":"A Bustamante Valdivia","year":"2015","unstructured":"Bustamante Valdivia, A., Maia, J. & Nevill, A. Identifying the ideal body size and shape characteristics associated with children\u2019s physical performance tests in Peru. Scand. J. Med. Sci. Sports. 25, e155\u2013165. https:\/\/doi.org\/10.1111\/sms.12231 (2015).","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"95461_CR91","doi-asserted-by":"publisher","first-page":"1434","DOI":"10.1080\/02640414.2018.1562615","volume":"37","author":"N Lovecchio","year":"2019","unstructured":"Lovecchio, N., Giuriato, M., Zago, M. & Nevill, A. Identifying the optimal body shape and composition associated with strength outcomes in children and adolescent according to place of residence: an allometric approach. J. Sports Sci. 37, 1434\u20131441. https:\/\/doi.org\/10.1080\/02640414.2018.1562615 (2019).","journal-title":"J. Sports Sci."},{"key":"95461_CR92","doi-asserted-by":"publisher","first-page":"e0149493","DOI":"10.1371\/journal.pone.0149493","volume":"11","author":"S Silva","year":"2016","unstructured":"Silva, S. et al. An allometric modelling approach to identify the optimal body shape associated with, and differences between Brazilian and Peruvian youth motor performance. PLoS One. 11, e0149493. https:\/\/doi.org\/10.1371\/journal.pone.0149493 (2016).","journal-title":"PLoS One"},{"key":"95461_CR93","doi-asserted-by":"publisher","first-page":"701","DOI":"10.1249\/mss.0b013e31802f0512","volume":"39","author":"YC Huang","year":"2007","unstructured":"Huang, Y. C. & Malina, R. M. BMI and Health-Related physical fitness in Taiwanese youth 9\u201318 years. Med. Sci. Sports Exerc. 39, 701. https:\/\/doi.org\/10.1249\/mss.0b013e31802f0512 (2007).","journal-title":"Med. Sci. Sports Exerc."},{"key":"95461_CR94","doi-asserted-by":"publisher","first-page":"e0233362","DOI":"10.1371\/journal.pone.0233362","volume":"15","author":"F Fiori","year":"2020","unstructured":"Fiori, F. et al. Relationship between body mass index and physical fitness in Italian prepubertal schoolchildren. PLoS One. 15, e0233362. https:\/\/doi.org\/10.1371\/journal.pone.0233362 (2020).","journal-title":"PLoS One"},{"key":"95461_CR95","doi-asserted-by":"publisher","first-page":"1446","DOI":"10.1186\/s12889-021-11284-9","volume":"21","author":"L Rittsteiger","year":"2021","unstructured":"Rittsteiger, L. et al. Sports participation of children and adolescents in Germany: disentangling the influence of parental socioeconomic status. BMC Public. Health. 21, 1446. https:\/\/doi.org\/10.1186\/s12889-021-11284-9 (2021).","journal-title":"BMC Public. Health"},{"key":"95461_CR96","doi-asserted-by":"publisher","first-page":"935245","DOI":"10.1155\/2013\/935245","volume":"2013","author":"C Drenowatz","year":"2013","unstructured":"Drenowatz, C. et al. Organized sports, overweight, and physical fitness in primary school children in Germany. J. Obes. 2013, 935245. https:\/\/doi.org\/10.1155\/2013\/935245 (2013).","journal-title":"J. Obes."},{"key":"95461_CR97","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1186\/s12955-021-01766-0","volume":"19","author":"A Bermejo-Cantarero","year":"2021","unstructured":"Bermejo-Cantarero, A. et al. Relationship between both cardiorespiratory and muscular fitness and health-related quality of life in children and adolescents: a systematic review and meta-analysis of observational studies. Health Qual. Life Outcomes. 19, 127. https:\/\/doi.org\/10.1186\/s12955-021-01766-0 (2021).","journal-title":"Health Qual. Life Outcomes"},{"key":"95461_CR98","doi-asserted-by":"publisher","first-page":"e13019","DOI":"10.1111\/desc.13019","volume":"24","author":"A Meijer","year":"2021","unstructured":"Meijer, A. et al. Cardiovascular fitness and executive functioning in primary school-aged children. Dev. Sci. 24, e13019. https:\/\/doi.org\/10.1111\/desc.13019 (2021).","journal-title":"Dev. Sci."},{"key":"95461_CR99","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1007\/s10648-023-09759-9","volume":"35","author":"AC Brady","year":"2023","unstructured":"Brady, A. C., Griffin, M. M., Lewis, A. R., Fong, C. J. & Robinson, D. H. How scientific is educational psychology research?? The increasing trend of squeezing causality and recommendations from Non-intervention studies. Educational Psychol. Rev. 35, 37. https:\/\/doi.org\/10.1007\/s10648-023-09759-9 (2023).","journal-title":"Educational Psychol. Rev."},{"key":"95461_CR100","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1007\/s10648-023-09777-7","volume":"35","author":"MP Grosz","year":"2023","unstructured":"Grosz, M. P. Should researchers make causal inferences and recommendations for practice on the basis of nonexperimental studies? Educational Psychol. Rev. 35, 57. https:\/\/doi.org\/10.1007\/s10648-023-09777-7 (2023).","journal-title":"Educational Psychol. Rev."},{"key":"95461_CR101","doi-asserted-by":"publisher","first-page":"806","DOI":"10.1177\/0011000006288127","volume":"34","author":"RL Worthington","year":"2006","unstructured":"Worthington, R. L. & Whittaker, T. A. Scale development research:a content analysis and recommendations for best practices. Couns. Psychol. 34, 806\u2013838. https:\/\/doi.org\/10.1177\/0011000006288127 (2006).","journal-title":"Couns. Psychol."},{"key":"95461_CR102","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1007\/s00038-016-0811-2","volume":"61","author":"M Zaqout","year":"2016","unstructured":"Zaqout, M. et al. Determinant factors of physical fitness in European children. Int. J. Public. Health. 61, 573\u2013582. https:\/\/doi.org\/10.1007\/s00038-016-0811-2 (2016).","journal-title":"Int. J. Public. Health"},{"key":"95461_CR103","doi-asserted-by":"publisher","first-page":"e896","DOI":"10.1542\/peds.2013-3169","volume":"133","author":"MD Peterson","year":"2014","unstructured":"Peterson, M. D., Saltarelli, W. A., Visich, P. S. & Gordon, P. M. Strength capacity and cardiometabolic risk clustering in adolescents. Pediatrics 133, e896\u2013903. https:\/\/doi.org\/10.1542\/peds.2013-3169 (2014).","journal-title":"Pediatrics"},{"key":"95461_CR104","unstructured":"W\u00f6hrl, T., Teich, P., B\u00e4hr, F. & Kliegl, R. Assessing bias of parental report of children\u2019s body mass and body height with measures of physical fitness. Technical Report: German Kids Fitness Lab, University of Erfurt. (2023)."},{"key":"95461_CR105","unstructured":"Kliegl, R., Teich, P., W\u00f6hrl, T., B\u00e4hr, F. & Golle, K. Assessing bias of parental report of children\u2019s body mass and body height with measures of physical fitness. Technical Report: German Kids Fitness Lab, University of Erfurt. (2023)."},{"key":"95461_CR106","doi-asserted-by":"publisher","DOI":"10.3389\/fpubh.2021.720589","author":"T Eberhardt","year":"2021","unstructured":"Eberhardt, T., B\u00f6s, K. & Niessner, C. The fitness barometer: A best practice example for monitoring motor performance with pooled data collected from practitioners. Front. Public. Health. 9 https:\/\/doi.org\/10.3389\/fpubh.2021.720589 (2021).","journal-title":"Front. Public. Health"},{"key":"95461_CR107","doi-asserted-by":"publisher","first-page":"86","DOI":"10.1016\/j.pcad.2019.01.002","volume":"62","author":"LA Kaminsky","year":"2019","unstructured":"Kaminsky, L. A. et al. Cardiorespiratory fitness and cardiovascular disease - The past, present, and future. Prog Cardiovasc. Dis. 62, 86\u201393. https:\/\/doi.org\/10.1016\/j.pcad.2019.01.002 (2019).","journal-title":"Prog Cardiovasc. Dis."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-95461-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-95461-5","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-95461-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,10]],"date-time":"2025-04-10T07:50:19Z","timestamp":1744271419000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-95461-5"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,2]]},"references-count":107,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["95461"],"URL":"https:\/\/doi.org\/10.1038\/s41598-025-95461-5","relation":{"has-preprint":[{"id-type":"doi","id":"10.21203\/rs.3.rs-3885133\/v1","asserted-by":"object"}]},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,2]]},"assertion":[{"value":"21 January 2024","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"21 March 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 April 2025","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"11300"}}