{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T06:30:55Z","timestamp":1787725855711,"version":"build-2784847793"},"reference-count":40,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T00:00:00Z","timestamp":1787702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Physical fitness is widely regarded as an important indicator of overall health and functional capacity. However, cross-sectional studies consistently report declining fitness levels and rising overweight\/obesity among college students. Longitudinal research tracking individual developmental trajectories remains scarce, and the \u201cfat but fit paradox\u201d is underexplored in this population. This study aimed to model 4-year trajectories of physical fitness indicators (PFI) across body mass index (BMI) categories, and to test the existence of the \u201cfat but fit paradox\u201d.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This study used de-identified, individual-level longitudinal data comprising four annual physical fitness assessments from 183,075 Han Chinese college students across 140 universities in Chengdu, China. MG-LGCMs were constructed to examine developmental trajectories of physical fitness indicators, with baseline BMI category as the grouping variable and gender as a covariate.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Results revealed significant heterogeneity across BMI categories. The normal-weight group exhibited the highest baseline fitness yet showed non-significant linear growth, whereas the obese group, despite the lowest baseline, demonstrated the fastest improvement. For gravity-dependent indicators\u2013endurance running, pull-ups (males), and 1-minute sit-ups (females)\u2013overweight and obese groups initially displayed a disadvantage but subsequently improved significantly faster. Absolute forced vital capacity followed a \u201cfat but fit paradox,\u201d with higher-BMI groups maintaining superior score across 4 years. Flexibility consistently favored the normal-weight group. Gender significantly moderated both initial status and rate of change: males showed steeper acceleration across most motor domains, while females maintained baseline superiority in flexibility.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>These findings challenge uniform weight-centric assumptions about physical fitness. They highlight the need for trajectory-informed, intersectional intervention strategies in collegiate physical education and health promotion.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fpubh.2026.1917457","type":"journal-article","created":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T06:00:41Z","timestamp":1787724041000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Longitudinal trajectories of physical fitness in Chinese college students: a multi-group latent growth curve analysis"],"prefix":"10.3389","volume":"14","author":[{"given":"Mei","family":"Jiang","sequence":"first","affiliation":[{"name":"Sports Institute, Chengdu University of Technology","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhou","family":"He","sequence":"additional","affiliation":[{"name":"School of Mathematics, Southwest Jiaotong University","place":["Chengdu, Sichuan, China"]},{"name":"Sichuan Provincial Department of Education, Sichuan Province Big Data Research and Joint Application Technology Center of Student Health","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,26]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/sj.ijo.0803774","article-title":"Sj\u00f6str\u00f6m M. 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