000096022 001__ 96022 000096022 005__ 20230914083226.0 000096022 0247_ $$2doi$$a10.14814/phy2.14053 000096022 0248_ $$2sideral$$a112481 000096022 037__ $$aART-2019-112481 000096022 041__ $$aeng 000096022 100__ $$0(orcid)0000-0002-1473-1870$$aGonzález-Haro, C. 000096022 245__ $$aConcordance between 13 C: 12 C ratio technique respect to indirect calorimetry to estimate carbohydrate and Fat oxidation rates by means stoichiometric equations during exercise. A reliability and agreement study 000096022 260__ $$c2019 000096022 5060_ $$aAccess copy available to the general public$$fUnrestricted 000096022 5203_ $$aIndirect calorimetry is a tool used routinely by sport/exercise physiologist to assess the metabolic response to training and to nutritional interventions. There are different stoichiometric equations to estimate fat (Fat OxR ) and carbohydrates (CHO O xR ) oxidation rates, however there are not enough information in literature about what are the most accurate equations. The purpose of this study was to determine the concordance between indirect calorimetry and a method of reference for stoichiometric equations used to estimate Fat OxR and CHO O xR . Concordance between indirect calorimetry and the method of reference ( 13 C to 12 C ratio ( 13 C: 12 C ratio) technique) for key stoichiometric equations was assessed in well-trained triathletes. Subjects carried out a carbohydrate depletion-repletion protocol, labeling the glycogen stores with 13 C, and a laboratory test to assess the 13 C metabolic response during a wide range of aerobic intensities during exercise. All the equations showed a narrow agreement interval (¿) (CHO O xR nPC (protein component negligible): -0.308, 0.308, CHO O xR PC (protein component): -0.268, 0.268, Fat OxR nPC and PC: -0.032, 0.032 (g·min -1 )). Fat OxR showed a similar concordance (28–32%) with CHO O xR nPC ranging from 55% to 75%, and for CHO O xR PC between 51% to 71%. None of the stoichiometric equations met a perfect agreement with the method of reference. The Jeukendrup and Wallis equation showed the best concordance for CHO O xR nPC whilst the Frayn and Ferrannini (Glu) equations had the best agreement for CHO O xR PC. All Fat OxR equations showed similar concordances and they are able to be used indistinctly. © 2019 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society. 000096022 536__ $$9info:eu-repo/grantAgreement/ES/MICINN/DEP2008-03204 000096022 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/ 000096022 592__ $$a0.909$$b2019 000096022 593__ $$aPhysiology (medical)$$c2019$$dQ2 000096022 593__ $$aPhysiology$$c2019$$dQ2 000096022 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000096022 773__ $$g7, 8 (2019), e14053 [17 pp.]$$pPhysiol. reports$$tPhysiological Reports$$x2051-817X 000096022 8564_ $$s374878$$uhttps://zaguan.unizar.es/record/96022/files/texto_completo.pdf$$yVersión publicada 000096022 8564_ $$s45009$$uhttps://zaguan.unizar.es/record/96022/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000096022 909CO $$ooai:zaguan.unizar.es:96022$$particulos$$pdriver 000096022 951__ $$a2023-09-13-10:43:04 000096022 980__ $$aARTICLE