title: Lactate minimum underestimates the maximal lactate steady-state in swimming mice.
abstract: The intensity of lactate minimum (LM) has presented a good estimate of the intensity of maximal lactate steady-state (MLSS); however, this relationship has not yet been verified in the mouse model. We proposed validating the LM protocol for swimming mice by investigating the relationship among intensities of LM and MLSS as well as differences between sexes, in terms of aerobic capacity. Nineteen mice (male: 10, female: 9) were submitted to the evaluation protocols for LM and MLSS. The LM protocol consisted of hyperlactatemia induction (30 s exercise (13% body mass (bm)), 30 s resting pause and exhaustive exercise (13% bm), 9 min resting pause and incremental test). The LM underestimated MLSS (mice: 17.6%; male: 13.5%; female: 21.6%). Pearson's analysis showed a strong correlation among intensities of MLSS and LM (male (r = 0.67, p = 0.033); female (r = 0.86, p = 0.003)), but without agreement between protocols. The Bland-Altman analysis showed that bias was higher for females (1.5 (0.98) % bm; mean (MLSS and LM): 4.4%-6.4% bm) as compared with males (0.84 (1.24) % bm; mean (MLSS and LM): 4.5%-7.5% bm). The error associated with the estimated of intensity for males was lower when compared with the range of means for MLSS and LM. Therefore, the LM test could be used to determine individual aerobic intensity for males (considering the bias) but not females. Furthermore, the females supported higher intensities than the males. The differences in body mass between sexes could not explain the higher intensities supported by the females.
authors.affiliation: a Laboratory of Applied Sports Physiology, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Natalia Almeida
authors.initials: NA
authors.lastname: Rodrigues
authors.affiliation: b Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Adriana Souza
authors.initials: AS
authors.lastname: Torsoni
authors.affiliation: b Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: Fante
authors.affiliation: a Laboratory of Applied Sports Physiology, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Ivan Gustavo Masselli
authors.initials: IG
authors.lastname: Dos Reis
authors.affiliation: a Laboratory of Applied Sports Physiology, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Claudio Alexandre
authors.initials: CA
authors.lastname: Gobatto
authors.affiliation: a Laboratory of Applied Sports Physiology, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
authors.forename: Fúlvia Barros
authors.initials: FB
authors.lastname: Manchado-Gobatto
mesh_terms: D015308:Anaerobic Threshold; D000818:Animals; D001835:Body Weight; D005080:Exercise Test / Q000662:veterinary*; D017079:Exercise Tolerance; D005221:Fatigue / Q000097:blood / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D005260:Female; D065906:Hyperlactatemia / Q000097:blood / Q000209:etiology / Q000378:metabolism / Q000662:veterinary*; D007756:Laboratory Animal Science / Q000379:methods; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D051379:Mice; D008954:Models, Biological; D005082:Physical Exertion; D015203:Reproducibility of Results; D012727:Sex Characteristics; D013550:Swimming; D016474:Weight-Bearing
chemical_list: D019344:Lactic Acid
keywords: aerobic capacity; anaerobic threshold; blood lactate; capacité aérobie; lactate sanguin; maximal lactate steady state; maximum de lactate en régime stable; seuil anaérobie