title: Oxygen uptake, respiratory exchange ratio, or total distance: a comparison of methods to equalize exercise volume in Wistar rats.
abstract: This study compared strategies to equalize the volume of aerobic exercise performed with different intensities by Wistar rats, based on the distance covered during exercise bouts and energy expenditure (EE, isocaloric sessions) obtained from oxygen uptake (V̇O2) or respiratory exchange ratio (RER). Thirty-three male rats (270.5±12.8 g) underwent maximal exercise tests to determine V̇O2 reserve (V̇O2R), being randomly assigned to three groups: moderate-intensity continuous exercise at speed corresponding to 50% V̇O2R (MIC; n=11); high-intensity continuous exercise at 80% V̇O2R (HIC; n=11); and high-intensity intermittent exercise (HII; n=11) at 60% V̇O2R (3 min) and 80% V̇O2R (4 min). Exercise duration was calculated individually to elicit EE of 5 kcal in each session. No difference between groups was found for total running distance (MIC: 801±46, HIC: 734±42, HII: 885±64 m; P=0.13). Total EE measured by RER was systematically underestimated compared to values obtained from V̇O2 (HII: 4.5% and MIC: 6.2%, P<0.05). Total EE (calculated from V̇O2), and duration of HIC bouts (2.8 kcal and 30.8±2.2 min) were lower (P<0.0001) than in MIC (4.9 kcal and 64.7±1.8 min) and HII (4.7 kcal and 46.9±2.2 min). Predicted and actual values of total V̇O2, total EE, and duration of isocaloric sessions were similar in MIC and HII (P>0.05), which were both higher than in HIC (P<0.0001). In conclusion, the time to achieve a given EE in exercise bouts with different intensities did not correspond to the total distance. Therefore, the volume of aerobic exercise in protocols involving Wistar rats should be equalized using EE rather than total covered distance.
authors.affiliation: Laboratório de Atividade Física e Promoção da Saúde, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.|Laboratório de Pesquisa Clínica e Experimental em Biologia Vascular, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: L S
authors.initials: LS
authors.lastname: Paes
authors.affiliation: Laboratório de Atividade Física e Promoção da Saúde, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: J P
authors.initials: JP
authors.lastname: Borges
authors.affiliation: Laboratório de Atividade Física e Promoção da Saúde, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: F A
authors.initials: FA
authors.lastname: Cunha
authors.affiliation: Laboratório de Pesquisa Clínica e Experimental em Biologia Vascular, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: M G C
authors.initials: MG
authors.lastname: Souza
authors.affiliation: Laboratório de Pesquisa Clínica e Experimental em Biologia Vascular, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: F Z G A
authors.initials: FZ
authors.lastname: Cyrino
authors.affiliation: Laboratório de Pesquisa Clínica e Experimental em Biologia Vascular, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: D A
authors.initials: DA
authors.lastname: Bottino
authors.affiliation: Laboratório de Pesquisa Clínica e Experimental em Biologia Vascular, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: E
authors.initials: E
authors.lastname: Bouskela
authors.affiliation: Laboratório de Atividade Física e Promoção da Saúde, Instituto de Educação Física e Desportos, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.|Programa de Pós-Graduação em Ciências da Atividade Física, Universidade Salgado de Oliveira, Niterói, RJ, Brasil.
authors.forename: P
authors.initials: P
authors.lastname: Farinatti
mesh_terms: D000818:Animals; D004734:Energy Metabolism / Q000502:physiology*; D005080:Exercise Test / Q000592:standards; D008297:Male; D023421:Models, Animal; D010101:Oxygen Consumption / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000379:methods / Q000502:physiology*; D011897:Random Allocation; D017208:Rats, Wistar; D012420:Running / Q000502:physiology