LACTATE MINIMUM UNDERESTIMATES THE MAXIMAL LACTATE STEADY STATE IN SWIMMING MICE

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 genders, 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 % 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%). Pearsonâ 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 and Altman analysis showed that bias was higher for females (1.5 [0.98] % bm; Mean [MLSS and LM]: 4.4â 6.4% bm) as compared to males (0.84 [1.24] % bm; Mean [MLSS and LM]: 4.5â 7.5% bm). The error associated with the estimated of intensity for males was lower when compared to 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 genders could not explain the higher intensities supported by the females.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author