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Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]

BACKGROUND: To determine the validity of the lactate threshold (LT) and maximal oxygen uptake ([Image: see text] ) determined during graded exercise test (GXT) of different durations and using different LT calculations. Trained male cyclists (n = 17) completed five GXTs of varying stage length (1, 3...

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Autores principales: Jamnick, Nicholas A., Botella, Javier, Pyne, David B., Bishop, David J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066218/
https://www.ncbi.nlm.nih.gov/pubmed/30059543
http://dx.doi.org/10.1371/journal.pone.0199794
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author Jamnick, Nicholas A.
Botella, Javier
Pyne, David B.
Bishop, David J.
author_facet Jamnick, Nicholas A.
Botella, Javier
Pyne, David B.
Bishop, David J.
author_sort Jamnick, Nicholas A.
collection PubMed
description BACKGROUND: To determine the validity of the lactate threshold (LT) and maximal oxygen uptake ([Image: see text] ) determined during graded exercise test (GXT) of different durations and using different LT calculations. Trained male cyclists (n = 17) completed five GXTs of varying stage length (1, 3, 4, 7 and 10 min) to establish the LT, and a series of 30-min constant power bouts to establish the maximal lactate steady state (MLSS). [Image: see text] was assessed during each GXT and a subsequent verification exhaustive bout (VEB), and 14 different LTs were calculated from four of the GXTs (3, 4, 7 and 10 min)—yielding a total 56 LTs. Agreement was assessed between the highest [Image: see text] measured during each GXT ([Image: see text] ) as well as between each LT and MLSS. [Image: see text] and LT data were analysed using mean difference (MD) and intraclass correlation (ICC). RESULTS: The [Image: see text] value from GXT(1) was 61.0 ± 5.3 mL(.)kg(-1.)min(-1) and the peak power 420 ± 55 W (mean ± SD). The power at the MLSS was 264 ± 39 W. [Image: see text] from GXT(3, 4, 7, 10) underestimated [Image: see text] by ~1–5 mL(.)kg(-1.)min(-1). Many of the traditional LT methods were not valid and a newly developed Modified D(max) method derived from GXT(4) provided the most valid estimate of the MLSS (MD = 1.1 W; ICC = 0.96). CONCLUSION: The data highlight how GXT protocol design and data analysis influence the determination of both [Image: see text] and LT. It is also apparent that [Image: see text] and LT cannot be determined in a single GXT, even with the inclusion of a VEB.
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spelling pubmed-60662182018-08-10 Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text] Jamnick, Nicholas A. Botella, Javier Pyne, David B. Bishop, David J. PLoS One Research Article BACKGROUND: To determine the validity of the lactate threshold (LT) and maximal oxygen uptake ([Image: see text] ) determined during graded exercise test (GXT) of different durations and using different LT calculations. Trained male cyclists (n = 17) completed five GXTs of varying stage length (1, 3, 4, 7 and 10 min) to establish the LT, and a series of 30-min constant power bouts to establish the maximal lactate steady state (MLSS). [Image: see text] was assessed during each GXT and a subsequent verification exhaustive bout (VEB), and 14 different LTs were calculated from four of the GXTs (3, 4, 7 and 10 min)—yielding a total 56 LTs. Agreement was assessed between the highest [Image: see text] measured during each GXT ([Image: see text] ) as well as between each LT and MLSS. [Image: see text] and LT data were analysed using mean difference (MD) and intraclass correlation (ICC). RESULTS: The [Image: see text] value from GXT(1) was 61.0 ± 5.3 mL(.)kg(-1.)min(-1) and the peak power 420 ± 55 W (mean ± SD). The power at the MLSS was 264 ± 39 W. [Image: see text] from GXT(3, 4, 7, 10) underestimated [Image: see text] by ~1–5 mL(.)kg(-1.)min(-1). Many of the traditional LT methods were not valid and a newly developed Modified D(max) method derived from GXT(4) provided the most valid estimate of the MLSS (MD = 1.1 W; ICC = 0.96). CONCLUSION: The data highlight how GXT protocol design and data analysis influence the determination of both [Image: see text] and LT. It is also apparent that [Image: see text] and LT cannot be determined in a single GXT, even with the inclusion of a VEB. Public Library of Science 2018-07-30 /pmc/articles/PMC6066218/ /pubmed/30059543 http://dx.doi.org/10.1371/journal.pone.0199794 Text en © 2018 Jamnick et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Jamnick, Nicholas A.
Botella, Javier
Pyne, David B.
Bishop, David J.
Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title_full Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title_fullStr Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title_full_unstemmed Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title_short Manipulating graded exercise test variables affects the validity of the lactate threshold and [Image: see text]
title_sort manipulating graded exercise test variables affects the validity of the lactate threshold and [image: see text]
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066218/
https://www.ncbi.nlm.nih.gov/pubmed/30059543
http://dx.doi.org/10.1371/journal.pone.0199794
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