Journal article
Increases in motor unit action potential amplitudes are related to muscle hypertrophy following eight weeks of high-intensity exercise training in females
European journal of sport science, Vol.21(10), pp.1403-1413
10/03/2021
DOI: 10.1080/17461391.2020.1836262
PMCID: PMC9762464
PMID: 33043836
Abstract
We examined the motor unit action potential amplitude versus recruitment threshold relationship (MUAP(AMP)-RT) as an indicator of MU-specific hypertrophy following high-intensity exercise training in females. Participants were assigned to either a high-intensity exercise (EX, n = 9) or control (CON, n = 18) condition and completed pre- (PRE) and post-testing (POST) during which maximal voluntary isometric leg extension strength (MVIT), vastus lateralis (VL) muscle cross sectional area (mCSA), whole leg skeletal muscle mass (SMMRL), and high-density surface EMG (HD-sEMG) signals were recorded from the VL during an isometric ramp contraction at 70% MVIT. The HD-sEMG signals were decomposed and yielded a MUAP(AMP) and an absolute (ABS; Nm) and normalized (NORM; %MVIC) RT for each MU. Individual MUAP(AMP)-RT slopes and intercepts were calculated for each subject. Changes in the pooled MUAP(AMP)-RT relationships for each group were also examined. Finally, relationships among individual changes in slopes of MUAP(AMP)-RT and individual changes in mCSA and SMMRL were examined. Training elicited increases in MVIT (+18%), mCSA (+12%), and mean and pooled slopes of MUAP(AMP)-RTNORM. The individual changes in slopes of both the MUAP(AMP)-RT relationships were moderately to strongly (r = 0.48-0.68) related to changes in mCSA and SMMRL. Eight-weeks of high-intensity exercise elicited increases in MUAP(AMP)-RT slope in females. Further, the observed change in slope was related to both VL mCSA and SMM of the tested leg. However, changes in slope for the MUAP(AMP)-RT relationship were more subdued when MUAP(AMP) was expressed relative to the absolute versus relative RT.
Details
- Title: Subtitle
- Increases in motor unit action potential amplitudes are related to muscle hypertrophy following eight weeks of high-intensity exercise training in females
- Creators
- Nathaniel D. M. Jenkins - Oklahoma State UniversityEmily. M. Rogers - Oklahoma State UniversityNile F. Banks - Oklahoma State UniversityTyler W. D. Muddle - Oklahoma State UniversityRyan J. Colquhoun - University of South Alabama
- Resource Type
- Journal article
- Publication Details
- European journal of sport science, Vol.21(10), pp.1403-1413
- DOI
- 10.1080/17461391.2020.1836262
- PMID
- 33043836
- PMCID
- PMC9762464
- NLM abbreviation
- Eur J Sport Sci
- ISSN
- 1746-1391
- eISSN
- 1536-7290
- Publisher
- Taylor & Francis
- Number of pages
- 11
- Grant note
- P20GM109097 / CIRCA (The Center for Integrative Research on Childhood Adversity) National Institute of General Medical Sciences; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of General Medical Sciences (NIGMS)
- Language
- English
- Date published
- 10/03/2021
- Academic Unit
- Center for Social Science Innovation; Injury Prevention Research Center; Health, Sport, and Human Physiology ; Internal Medicine
- Record Identifier
- 9984259643202771
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