{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T09:06:10Z","timestamp":1789031170832,"version":"build-2803163510"},"reference-count":29,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Background: This study analyzed the time allocation characteristics of 24-h movement behaviors among firefighter cadets, clarified their independent associations with physical fitness performance, and identified key predictors of physical fitness using compositional data analysis. Methods: A total of 333 fire academy cadets (326 males, 7 females) from five specialty directions were recruited. ActiGraph GT3X-BT accelerometers were used to objectively measure 24-h movement behaviors over seven consecutive days. Isometric log-ratio (ILR) transformation was applied to compositional time-use data, and bidirectional stepwise regression based on AIC was used to identify key predictors. Robustness checks included bootstrap resampling, 10-fold cross-validation, leave-one-out sensitivity analysis, and influence diagnostics. Results: The optimal model (F = 14.46, p &lt; 0.001, adjusted R2 = 0.260) identified weight (\u03b2 = \u22120.42, p &lt; 0.001), sex (\u03b2 = \u221216.14, p &lt; 0.001), age (\u03b2 = 2.00, p &lt; 0.01), height (\u03b2 = 0.18, p &lt; 0.05), and Fire Rescue Technology (Fire Facilities) specialty (\u03b2 = \u22124.87, p &lt; 0.001) as significant predictors. The sex association should be interpreted as exploratory given the very small female subsample (n = 7). All ILR-transformed movement components were removed by stepwise regression. The weekend model showed slightly higher explanatory power (adjusted R2 = 0.270) than the weekday model (adjusted R2 = 0.260). Conclusions: Demographic and physical characteristics, rather than 24-h movement composition, are the primary predictors of physical fitness performance in this highly structured training population. The sex-related finding is exploratory and sample-specific due to the small female subsample. These findings provide evidence-based guidance for physical fitness training program design in fire academies and similar structured training environments.<\/jats:p>","DOI":"10.3390\/s26185700","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T14:55:46Z","timestamp":1788879346000},"page":"5700","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Wearable Sensor-Based Assessment of 24-Hour Movement Behaviors and Physical Fitness Performance in Fire Academy Cadets"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-9099-667X","authenticated-orcid":false,"given":"Gaodong","family":"Duan","sequence":"first","affiliation":[{"name":"School of Physical Education, Hunan University, Changsha 410082, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Zixia","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Physical Education, Hunan University, Changsha 410082, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"}]},{"given":"Zongkai","family":"Zhou","sequence":"additional","affiliation":[{"name":"School of Physical Education, Hunan University, Changsha 410082, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-5683-1925","authenticated-orcid":false,"given":"Zuguo","family":"Tian","sequence":"additional","affiliation":[{"name":"School of Physical Education, Hunan University, Changsha 410082, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"visualization","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"key":"ref_1","first-page":"53","article-title":"Occupational physical fitness characteristics and training development ideas for fire rescue personnel under the background of all-hazards and large-scale emergency response","volume":"27","author":"Song","year":"2023","journal-title":"Sports Sci. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"578","DOI":"10.1519\/JSC.0000000000000663","article-title":"The effect of a novel tactical training program on physical fitness and occupational performance in firefighters","volume":"29","author":"Pawlak","year":"2015","journal-title":"J. Strength Cond. Res."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Stone, B.L., Alvar, B.A., Orr, R.M., Lockie, R.G., Johnson, Q.R., Goatcher, J., and Dawes, J.J. (2020). Impact of an 11-week strength and conditioning program on firefighter trainee fitness. Sustainability, 12.","DOI":"10.3390\/su12166541"},{"key":"ref_4","first-page":"251","article-title":"Utilizing multimodal high-intensity interval training for a firefighter training academy during the COVID-19 pandemic","volume":"75","author":"Mang","year":"2023","journal-title":"Work"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"801","DOI":"10.1503\/cmaj.051351","article-title":"Health benefits of physical activity: The evidence","volume":"174","author":"Warburton","year":"2006","journal-title":"Can. Med. Assoc. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1249\/MSS.0000000000001811","article-title":"The 24-hour activity cycle: A new paradigm for physical activity","volume":"51","author":"Rosenberger","year":"2019","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1093\/aje\/kwp163","article-title":"Isotemporal substitution paradigm for physical activity epidemiology and weight change","volume":"170","author":"Mekary","year":"2009","journal-title":"Am. J. Epidemiol."},{"key":"ref_8","first-page":"31","article-title":"The adiposity of children is associated with their lifestyle composition: A time-use approach","volume":"76","author":"Dumuid","year":"2015","journal-title":"Prev. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1139\/apnm-2016-0026","article-title":"Associations between sleep duration, sedentary time, physical activity, and health indicators among children and youth using compositional analyses","volume":"41","author":"Carson","year":"2016","journal-title":"Appl. Physiol. Nutr. Metab."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Li, R., Cui, D., Fan, Q., Zhao, L., Xia, Z., Zuo, T., Qiu, Y., Jiang, Q., Huo, J., and Wang, Z. (2025). The impact of 24-h movement behaviors on college students\u2019 physical fitness and its isotemporal substitution benefits: A compositional data analysis approach. BMC Public Health, 25.","DOI":"10.1186\/s12889-025-23715-y"},{"key":"ref_11","unstructured":"ActiGraph LLC (2019). ActiGraph GT3X-BT User Manual, ActiGraph."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1186\/s44167-024-00062-8","article-title":"A systematic review of research reporting practices in observational studies examining associations between 24-h movement behaviors and indicators of health using compositional data analysis","volume":"3","author":"Brown","year":"2024","journal-title":"J. Act. Sedentary Sleep Behav."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1087","DOI":"10.1249\/MSS.0000000000003119","article-title":"The time course of health, fitness, and occupational performance changes in recruits across a fire academy","volume":"55","author":"Wohlgemuth","year":"2023","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2223","DOI":"10.1249\/MSS.0000000000001356","article-title":"Changes in health and fitness in firefighter recruits: An observational cohort study","volume":"49","author":"Cornell","year":"2017","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_15","unstructured":"(2022). Writing Group of the Chinese Physical Activity Guidelines. Chinese Physical Activity Guidelines (2021). Chin. J. Public Health, 38, 129\u2013130."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Chizewski, A., Box, A., Kesler, R.M., and Petruzzello, S.J. (2021). High intensity functional training (HIFT) improves fitness in recruit firefighters. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph182413400"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"100009","DOI":"10.1016\/j.gloepi.2019.100009","article-title":"Decomposing the effects of physical activity and cardiorespiratory fitness on mortality","volume":"1","author":"Wolfson","year":"2019","journal-title":"Glob. Epidemiol."},{"key":"ref_18","first-page":"265","article-title":"Parametric optimisation of a pulmonary ventilator using the Taguchi method","volume":"76","year":"2025","journal-title":"J. Electr. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"272","DOI":"10.2478\/cee-2026-0022","article-title":"The impact of road infrastructure development on selected environmental, economic, and social indicators","volume":"22","year":"2026","journal-title":"Civ. Environ. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1779","DOI":"10.1111\/sms.14427","article-title":"Associations between combinations of 24-h movement behaviors and physical fitness among Chinese adolescents: Sex and age disparities","volume":"33","author":"Cai","year":"2023","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1479","DOI":"10.1038\/s41591-026-04237-5","article-title":"Physical activity for public health in the 21st century","volume":"32","author":"Salvo","year":"2026","journal-title":"Nat. Med."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1519\/JSC.0000000000001039","article-title":"Body composition is strongly associated with cardiorespiratory fitness in a large Brazilian firefighter cohort","volume":"30","author":"Nogueira","year":"2016","journal-title":"J. Strength Cond. Res."},{"key":"ref_23","first-page":"46","article-title":"Relationships between body composition and firefighter occupational performance: A systematic review and meta-analysis","volume":"82","author":"Martin","year":"2025","journal-title":"Work"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Ras, J., Smith, D.L., Kengne, A.P., Soteriades, E.S., and Leach, L. (2023). Physical fitness, cardiovascular and musculoskeletal health, and occupational performance in firefighters. Front. Public Health, 11.","DOI":"10.3389\/fpubh.2023.1241250"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1381","DOI":"10.1093\/milmed\/usab315","article-title":"Anthropometrics and body composition predict physical performance and selection to attend Special Forces training in United States Army soldiers","volume":"187","author":"Farina","year":"2022","journal-title":"Mil. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"S87","DOI":"10.1519\/JSC.0b013e31825ced6c","article-title":"Body composition and military performance: Many things to many people","volume":"26","author":"Friedl","year":"2012","journal-title":"J. Strength Cond. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1080\/17461391.2021.1916082","article-title":"Sex differences in the physical performance, physiological, and psycho-cognitive responses to military operational stress","volume":"22","author":"Conkright","year":"2022","journal-title":"Eur. J. Sport. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"8788","DOI":"10.1038\/s41598-025-92865-1","article-title":"Disparities in sports participation behavior among Chinese residents","volume":"15","author":"Peng","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.annepidem.2024.12.011","article-title":"Gender differences in physical activity and sport participation in adults across 28 European countries between 2005 and 2022","volume":"101","author":"Owen","year":"2025","journal-title":"Ann. Epidemiol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/18\/5700\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T08:09:48Z","timestamp":1789027788000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/18\/5700"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,8]]},"references-count":29,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["s26185700"],"URL":"https:\/\/doi.org\/10.3390\/s26185700","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,8]]}}}