Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration

Purpose: Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by the exercise (in mM) by 3.3 (or 3) mL·kg−1 per mM. Our purpose was to verify the value of thi...

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Main Authors: David W. Hill, John Michael Mihalek
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-01-01
Series:Frontiers in Physiology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fphys.2023.1283327/full
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author David W. Hill
John Michael Mihalek
author_facet David W. Hill
John Michael Mihalek
author_sort David W. Hill
collection DOAJ
description Purpose: Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by the exercise (in mM) by 3.3 (or 3) mL·kg−1 per mM. Our purpose was to verify the value of this conversion factor, using methods that were completely different from those of the original studies.Methods: Six women (mean ± SD), age, 23 ± 1 year; VO2max, 46 ± 4 mL·kg−1·min−1) and three men (23 ± 0 years; 54 ± 8 mL·kg−1·min−1) completed 6 min of heavy intensity exercise in conditions of normoxia and hypoxia (FIO2, ∼12%). VO2 was measured throughout the exercise and 7 min of recovery. The increase in glycolytic contribution was estimated as the reduction in aerobic contribution in hypoxia, after correction for the effects of hypoxia on the oxygen demand and on the contribution from phosphocreatine. The peak post-exercise blood lactate concentration was measured in fingerstick blood samples.Results: The ratio between the increase in estimated glycolytic contribution (in mL·kg–1) in hypoxia and the increase in peak blood lactate concentration (in mM) yielded an oxygen equivalent of 3.4 ± 0.4 mL·kg–1 per mM (range, 2.6 mL·kg−1 per mM to 4.0 mL·kg−1 per mM) for cycle ergometer exercise.Conclusion: These results generally support the use of a common conversion factor to calculate the glycolytic contribution from post-exercise blood lactate concentrations. However, there is some inter-individual variability in the conversion factor.
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spelling doaj.art-7ac2076921b34896b9208253664d211e2024-01-24T04:30:30ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2024-01-011410.3389/fphys.2023.12833271283327Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentrationDavid W. Hill0John Michael Mihalek1Applied Physiology Laboratory, University of North Texas, Denton, TX, United StatesCollege of Applied Human Sciences, West Virginia University, Morgantown, WV, United StatesPurpose: Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by the exercise (in mM) by 3.3 (or 3) mL·kg−1 per mM. Our purpose was to verify the value of this conversion factor, using methods that were completely different from those of the original studies.Methods: Six women (mean ± SD), age, 23 ± 1 year; VO2max, 46 ± 4 mL·kg−1·min−1) and three men (23 ± 0 years; 54 ± 8 mL·kg−1·min−1) completed 6 min of heavy intensity exercise in conditions of normoxia and hypoxia (FIO2, ∼12%). VO2 was measured throughout the exercise and 7 min of recovery. The increase in glycolytic contribution was estimated as the reduction in aerobic contribution in hypoxia, after correction for the effects of hypoxia on the oxygen demand and on the contribution from phosphocreatine. The peak post-exercise blood lactate concentration was measured in fingerstick blood samples.Results: The ratio between the increase in estimated glycolytic contribution (in mL·kg–1) in hypoxia and the increase in peak blood lactate concentration (in mM) yielded an oxygen equivalent of 3.4 ± 0.4 mL·kg–1 per mM (range, 2.6 mL·kg−1 per mM to 4.0 mL·kg−1 per mM) for cycle ergometer exercise.Conclusion: These results generally support the use of a common conversion factor to calculate the glycolytic contribution from post-exercise blood lactate concentrations. However, there is some inter-individual variability in the conversion factor.https://www.frontiersin.org/articles/10.3389/fphys.2023.1283327/fullanaerobiccyclingenergy demandexercise intensityglycolysisheavy intensity
spellingShingle David W. Hill
John Michael Mihalek
Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
Frontiers in Physiology
anaerobic
cycling
energy demand
exercise intensity
glycolysis
heavy intensity
title Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
title_full Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
title_fullStr Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
title_full_unstemmed Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
title_short Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration
title_sort calculation of a conversion factor for estimating the glycolytic contribution in exercise from post exercise blood lactate concentration
topic anaerobic
cycling
energy demand
exercise intensity
glycolysis
heavy intensity
url https://www.frontiersin.org/articles/10.3389/fphys.2023.1283327/full
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