163854 20260506141200.0 doi 10.1007/s00421-025-05947-3 sideral 146048 ART-2026-146048 eng Baltasar-Fernández, Iván Changes and major determinants of relative muscle power loss in older adults: results from an 8-year longitudinal study 2026 Objectives: This study aimed to evaluate longitudinal changes in relative sit-to-stand power (STSpower) in older adults and investigate contributing factors to its decline. Methods: 565 older adults (143 men and 422 women; ≥ 65 years) were tested at baseline and after 8 years of follow-up. Relative STSpower was estimated from the 30-s STS test using the Alcazar equation while body composition was assessed using bioelectrical impedance analysis. The basic components of relative STSpower (specific STSpower, leg muscle mass, body fat mass and fat-free mass) were calculated. Factors such as medication intake and daily walking and sitting time were recorded. Results: Relative STSpower declined significantly in both sexes, with greater reductions in men than women (11.8 vs 8.0%, p = 0.024). Losses were greater in men and women aged ≥75 years (− 2.0% and − 2.0%∙year−1, respectively) compared to those aged 65–69 years (− 1.1% and − 0.7% year−1, respectively). Approximately 95% of the average decline in relative STSpower was attributed to reductions in specific STSpower, while the remaining 5% was explained by the loss of leg muscle mass. Medication intake was associated with an increased risk of decreasing power in women (OR = 1.87, p = 0.049), while a trend was shown in men (OR = 2.58; p = 0.052). Sedentary time showed a tendency only in women (OR = 1.73; p = 0.085). Conclusion: Relative STSpower decreased progressively with aging, but differently in older men and women. This decline was primarily driven by reductions in specific STSpower, while the loss in leg muscle mass contributed to a lesser extent. Medication and sedentary time may influence power loss. info:eu-repo/grantAgreement/ES/AEI/RED2022-134800-T info:eu-repo/grantAgreement/ES/ISCIII/CB16-10-00477 info:eu-repo/grantAgreement/ES/MCD/EXP 104961 info:eu-repo/grantAgreement/ES/MCD/EXP 99828 info:eu-repo/grantAgreement/ES/MECD/EXERNET-DEP2005-00046 info:eu-repo/grantAgreement/ES/MECD/09-UPB-19 info:eu-repo/grantAgreement/ES/MECD/27-UPB-21 info:eu-repo/grantAgreement/ES/MECD/29-UPB-22 info:eu-repo/grantAgreement/ES/MECD/45-UPB-20 info:eu-repo/grantAgreement/ES/MECD/5-UPB-23 info:eu-repo/semantics/closedAccess All rights reserved http://www.europeana.eu/rights/rr-f/ info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Alcázar, Julián Gómez-Cabello, Alba (orcid)0000-0001-6492-2512 Moradell, Ana Universidad de Zaragoza (orcid)0000-0003-0330-5558 Pedrero Chamizo, Raquel Alegre, Luis M. Villa-Vicente, José Gerardo Gusi, Narcís González-Gross, Marcela Casajús, José Antonio Universidad de Zaragoza (orcid)0000-0002-7215-6931 Vicente-Rodríguez, Germán Universidad de Zaragoza (orcid)0000-0002-4303-4097 Ara, Ignacio 2008 640 Universidad de Zaragoza Dpto. Produc.Animal Cienc.Ali. Área Nutrición Bromatología 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 126 (2026), 1737-1750 EUR J APPL PHYSIOL EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY 1439-6319 4285534 http://zaguan.unizar.es/record/163854/files/texto_completo.pdf Versión publicada 2575681 http://zaguan.unizar.es/record/163854/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:163854 articulos driver 2026-05-06-14:10:09 ARTICLE