Extraordinary Fast-Twitch Fiber Abundance in Elite Weightlifters
| Autor: | Lauren M. Colenso-Semple, Jeremy W. Siu, Nathan Serrano, Pablo B. Costa, James R. Bagley, Kara K. Lazauskas, Andrew J. Galpin, Robert G. Lockie |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Male
Fast twitch muscle Physiology Biopsy Single fiber Social Sciences Skeletal Muscle Fibers Biochemistry Running Body Mass Index Contractile Proteins 0302 clinical medicine Animal Cells Secondary analysis Medicine and Health Sciences Psychology Public and Occupational Health Fiber Musculoskeletal System Multidisciplinary Fiber type Muscles Sports Science Muscle Fibers Fast-Twitch Medicine Female Cellular Types Anatomy Anaerobic exercise Research Article Sports Adult medicine.medical_specialty Weight Lifting Science Motor Proteins Actin Motors Surgical and Invasive Medical Procedures Myosins Biology Muscle Fibers Young Adult 03 medical and health sciences Molecular Motors Internal medicine medicine Humans Elite athletes Sports and Exercise Medicine Exercise Behavior Myosin Heavy Chains Fast-Twitch Muscle Fibers Biological Locomotion Biology and Life Sciences Proteins Cell Biology Physical Activity 030229 sport sciences Cytoskeletal Proteins Endocrinology Skeletal Muscles Physical Fitness Athletes Recreation 030217 neurology & neurosurgery |
| Zdroj: | PLoS ONE, Vol 14, Iss 3, p e0207975 (2019) PLoS ONE |
| DOI: | 10.1101/468744 |
| Popis: | Human skeletal muscle fibers exist across a continuum of slow → fast-twitch. The amount of each fibertype(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. These athletes displayed the highest MHC IIa concentrations ever reported in healthyVL(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%). The heavyweights accounted for 91% of the MHC IIa/IIx fibers. 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. These findings suggest athlete caliber (World vs. National), training experience, and body mass determine FT% more than sex and refutes the common pronouncement that women possess more slow and fewer fast-twitch fibers than men. Our results also show the abundance of pure MHC IIa and rarity of IIx in elite strength/power-trained athletes, indicate a potential link between MHC IIa/IIx frequency and body mass, and question the fidelity of HG as a measure of FT% distribution. The extreme fast-twitch abundance partially explains how elite weightlifters generate high forces in rapid time-frames. These data highlight the need for more cellular and molecular muscle research on elite anaerobic athletes. |
| Databáze: | OpenAIRE |
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