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Extraordinary fast-twitch fiber abundance in elite weightlifters
Human skeletal muscle fibers exist across a continuum of slow → fast-twitch. The amount of each fiber type (FT) influences muscle performance but remains largely unexplored in elite athletes, particularly from strength/power sports. To address this nescience, vastus lateralis (VL) biopsies were perf...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6436686/ https://www.ncbi.nlm.nih.gov/pubmed/30917128 http://dx.doi.org/10.1371/journal.pone.0207975 |
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author | Serrano, Nathan Colenso-Semple, Lauren M. Lazauskus, Kara K. Siu, Jeremy W. Bagley, James R. Lockie, Robert G. Costa, Pablo B. Galpin, Andrew J. |
author_facet | Serrano, Nathan Colenso-Semple, Lauren M. Lazauskus, Kara K. Siu, Jeremy W. Bagley, James R. Lockie, Robert G. Costa, Pablo B. Galpin, Andrew J. |
author_sort | Serrano, Nathan |
collection | PubMed |
description | Human skeletal muscle fibers exist across a continuum of slow → fast-twitch. The amount of each fiber type (FT) influences muscle performance but remains largely unexplored in elite athletes, particularly from strength/power sports. To address this nescience, vastus lateralis (VL) biopsies were performed on World/Olympic (female, n = 6, “WCF”) and National-caliber (female, n = 9, “NCF”; and male, n = 6, “NCM”) American weightlifters. Participant accolades included 3 Olympic Games, 19 World Championships, 25 National records, and >170 National/International medals. Samples were analyzed for myosin heavy chain (MHC) content via SDS-PAGE using two distinct techniques: single fiber (SF) distribution (%) and homogenate (HG) composition. The main finding was that these athletes displayed the highest pure MHC IIa concentrations ever reported in healthy VL (23±9% I, 5±3% I/IIa, 67±13% IIa, and 6±10% IIa/IIx), with WCF expressing a notable 71±17% (NCF = 67±8%, NCM = 63±16%). No pure MHC IIx were found with SF. Secondary analysis revealed the heavyweights accounted for 91% of the MHC IIa/IIx fibers, which caused a correlation between this FT and body mass. Additionally, when compared to SF, HG overestimated MHC I (23±9 vs. 31±9%) and IIx (0±0 vs. 3±6%) by misclassifying I/IIa fibers as I and IIa/IIx fibers as IIx, highlighting the limitation of HG as a measure of isoform distribution. These results collectively suggest that athlete caliber (World vs. National) and/or years competing in the sport determine FT% more than sex, particularly for MHC IIa. The extreme fast-twitch myofiber abundance likely explains how elite weightlifters generate high forces in rapid time-frames. |
format | Online Article Text |
id | pubmed-6436686 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-64366862019-04-12 Extraordinary fast-twitch fiber abundance in elite weightlifters Serrano, Nathan Colenso-Semple, Lauren M. Lazauskus, Kara K. Siu, Jeremy W. Bagley, James R. Lockie, Robert G. Costa, Pablo B. Galpin, Andrew J. PLoS One Research Article Human skeletal muscle fibers exist across a continuum of slow → fast-twitch. The amount of each fiber type (FT) influences muscle performance but remains largely unexplored in elite athletes, particularly from strength/power sports. To address this nescience, vastus lateralis (VL) biopsies were performed on World/Olympic (female, n = 6, “WCF”) and National-caliber (female, n = 9, “NCF”; and male, n = 6, “NCM”) American weightlifters. Participant accolades included 3 Olympic Games, 19 World Championships, 25 National records, and >170 National/International medals. Samples were analyzed for myosin heavy chain (MHC) content via SDS-PAGE using two distinct techniques: single fiber (SF) distribution (%) and homogenate (HG) composition. The main finding was that these athletes displayed the highest pure MHC IIa concentrations ever reported in healthy VL (23±9% I, 5±3% I/IIa, 67±13% IIa, and 6±10% IIa/IIx), with WCF expressing a notable 71±17% (NCF = 67±8%, NCM = 63±16%). No pure MHC IIx were found with SF. Secondary analysis revealed the heavyweights accounted for 91% of the MHC IIa/IIx fibers, which caused a correlation between this FT and body mass. Additionally, when compared to SF, HG overestimated MHC I (23±9 vs. 31±9%) and IIx (0±0 vs. 3±6%) by misclassifying I/IIa fibers as I and IIa/IIx fibers as IIx, highlighting the limitation of HG as a measure of isoform distribution. These results collectively suggest that athlete caliber (World vs. National) and/or years competing in the sport determine FT% more than sex, particularly for MHC IIa. The extreme fast-twitch myofiber abundance likely explains how elite weightlifters generate high forces in rapid time-frames. Public Library of Science 2019-03-27 /pmc/articles/PMC6436686/ /pubmed/30917128 http://dx.doi.org/10.1371/journal.pone.0207975 Text en © 2019 Serrano 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 Serrano, Nathan Colenso-Semple, Lauren M. Lazauskus, Kara K. Siu, Jeremy W. Bagley, James R. Lockie, Robert G. Costa, Pablo B. Galpin, Andrew J. Extraordinary fast-twitch fiber abundance in elite weightlifters |
title | Extraordinary fast-twitch fiber abundance in elite weightlifters |
title_full | Extraordinary fast-twitch fiber abundance in elite weightlifters |
title_fullStr | Extraordinary fast-twitch fiber abundance in elite weightlifters |
title_full_unstemmed | Extraordinary fast-twitch fiber abundance in elite weightlifters |
title_short | Extraordinary fast-twitch fiber abundance in elite weightlifters |
title_sort | extraordinary fast-twitch fiber abundance in elite weightlifters |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6436686/ https://www.ncbi.nlm.nih.gov/pubmed/30917128 http://dx.doi.org/10.1371/journal.pone.0207975 |
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