Baltasar-Fernández, Iván Alcázar, Julián Gómez-Cabello, Alba Moradell, Ana Pedrero Chamizo, Raquel Alegre, Luis M. Villa-Vicente, José Gerardo Gusi, Narcís González-Gross, Marcela Casajús, José Antonio Vicente-Rodríguez, Germán Ara, Ignacio Changes and major determinants of relative muscle power loss in older adults: results from an 8-year longitudinal study EUR J APPL PHYSIOL 10.1007/s00421-025-05947-3 2026 2026