Impact of methods for data selection on the day-to-day reproducibility of resting metabolic rate assessed with four different metabolic carts Alcántara Alcántara, Juan Manuel Jurado Fasoli, Lucas Dote Montero, Manuel Amaro Gahete, Francisco José Ruiz, J.R Sánchez Delgado, Guillermo Resting energy expenditure REE Indirect calorimetry Reliability Coefficient of variation Between-days reproducibility This work was supported by the Spanish Ministry of Economy and Competitiveness via Retos de la Sociedad grant DEP2016-79512-R (to JRR) , and European Regional Development Funds (ERDF) ; Spanish Ministry of Education grant (FPU15/04059 to JMAA; FPU19/01609 to LJ-F; and FPU18/03357 to MD -M) ; the University of Granada Plan Propio de Investigacion 2016 -Excellence actions: Unit of Excellence on Exercise and Health (to JRR) ; the University of Granada Plan Propio 2020 and 2018 Programa Contratos-Puente (to JMA and GS -D, respectively) , and Programa Perfeccionamiento de Doctores (to GS -D) ; Junta de Andalucia, Consejena de Conocimiento, Investigacion y Universidades grant SOMM17/6107/UGR (to JRR) via the ERDF; Grant FJC2020-044453-I funded by MCIN/AEI/10.13039/501100011033 and by "European Union Next- GenerationEU/PRTR " (to JMA) ; the Fundacion Alfonso Martin Escudero (to GS -D) ; and a Marie Sklodowska-Curie Actions-Individual Fellowship grant (Horizon2020, 101028941, to GS -D) . Background and aims: Accomplishing a high day-to-day reproducibility is important to detect changes in resting metabolic rate (RMR) and respiratory exchange ratio (RER) that may be produced after an intervention or for monitoring patients' metabolism over time. We aimed to analyze: (i) the influence of different methods for selecting indirect calorimetry data on RMR and RER assessments; and, (ii) whether these methods influence RMR and RER day-to-day reproducibility.Methods and results: Twenty-eight young adults accomplished 4 consecutive RMR assessments (30-min each), using the Q-NRG (Cosmed, Rome, Italy), the Vyntus CPX (Jaeger-CareFusion, H & ouml;chberg, Germany), the Omnical (Maastricht Instruments, Maastricht, The Netherlands), and the Ultima CardiO2 (Medgraphics Corporation, St. Paul, Minnesota, USA) carts, on 2 consecutive mornings. Three types of methods were used: (i) short (periods of 5 consecutive minutes; 6-10, 11-15, 16-20, 21-25, and 26-30 min) and long time intervals (TI) methods (6-25 and 6-30 min); (ii) steady state (SSt methods); and, (iii) methods filtering the data by thresholding from the mean RMR (filtering methods). RMR and RER were similar when using different methods (except RMR for the Vyntus and RER for the Q-NRG). Conversely, using different methods impacted RMR (all P <= 0.037) and/or RER (P <= 0.009) day-to-day reproducibility in all carts. The 6-25 min and the 6-30 min long TI methods yielded more reproducible measurements for all metabolic carts.Conclusion: The 6-25 min and 6-30 min should be the preferred methods for selecting data, as they result in the highest day-to-day reproducibility of RMR and RER assessments. 2023-12-20T13:21:43Z 2023-12-20T13:21:43Z 2023-11 journal article J.M.A. Alcántara et al. Impact of methods for data selection on the day-to-day reproducibility of resting metabolic rate assessed with four different metabolic carts. Nutrition, Metabolism & Cardiovascular Diseases (2023) 33, 2179e2188. [https://doi.org/10.1016/j.numecd.2023.07.017] https://hdl.handle.net/10481/86377 10.1016/j.numecd.2023.07.017 eng info:eu-repo/grantAgreement/EC/H2020/101028941 http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Elsevier