The breakpoint (BP) in lactate (La) was determined using the noninvasive V-slope and VE/VO2 methods. Eight normal male subjects performed three maximal graded exercise tests (GXT) with 3-min work stages during normal breathing (NB) and during irregular breathing with hypoventilation (IB-HV). The IB-HV resulted in mild but significantly increased arterialized-venous PCO2, PETCO2 and irregular VE/VO2 and irregular breathing frequency. The correlation coefficients for linear regressions of the La BP with the V-slope and VE/VO2 BPs during NB were: 0.77 (p < 0.05) and 0.79 (p < 0.05), respectively, and during IB-HV the correlations coefficients were: 0.82 (p < 0.05) and -0.02 (p > 0.05) for V-slope and VE/VO2 BPs, respectively. The differences were more apparent from the regression coefficients with the La BP; the slopes with NB for V-slope and VE/VO2 BPs were 1.06 +/- 0.40 SEM and 1.38 +/- 0.43; the intercepts with NB were -0.22 +/- 0.24 and -0.67 +/- 0.33, respectively. During IB-HV the slopes for the V-slope and VE/VO2 were 1.02 +/- 0.29 and -0.02 +/- 0.47, and the intercepts were -0.11 +/- 0.40 and 1.57 +/- 0.64, respectively. The VE/VO2 slope and intercept with IB-HV were notably different. It was concluded that the V-slope and VE/VO2 methods determine the La BP with 3-min stages during NB, whereas only the V-slope method determined the La BP with IB-HV.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.