Higher muscle fiber conduction velocity and early rate of torque development in chronically strength-trained individuals
Del Vecchio A, Negro F, Falla D, Bazzucchi , Farina D, Felici F (2018)
Publication Type: Journal article
Publication year: 2018
Journal
Book Volume: 125
Pages Range: 1218-1226
Journal Issue: 4
DOI: 10.1152/japplphysiol.00025.2018
Abstract
Strength-trained individuals (ST) develop greater levels of forc.compared with untrained subjects. These differences are partly of neural origin and can be explained by training-induced changes in the neural drive to the muscles. In the present study we hypothesize a greater rate of torque development (RTD) and faster recruitment of motor units with greater muscle fiber conduction velocity (MFCV) in S.compared with a control cohort. MFCV was assessed during maximal voluntary isometric explosive contractions of the elbow flexors in eight ST and eight control individuals. MFCV was estimated from high-density surface electromyogram recordings (128 electrodes) in intervals of 50 ms starting from the onset of the electromyogram. RTD and MFCV wer.computed and normalized to their maximal voluntary torque (MVT) values. The explosive torque of the ST was greater than in the control group in all time intervals analyzed (P < 0.001). The absolute MFCV values were also greater for the ST than for controls at all time intervals (P < 0.001). ST also achieved greater normalized RTD in the first 50 ms of contraction [887.6 (152) vs. 568.5 (148.66)%MVT/s, mean (SD), P < 0.001] and normalized MFCV before the rise in forc.compared with controls. We have shown for the first time that ST can recruit motor units with greater MFCV in a shorter amount of tim.compared with untrained subjects during maximal voluntary isometric explosive contractions. NEW & NOTEWORTHY Strength-trained individuals show neuromuscular adaptations. These adaptations have been partly related to changes in the neural drive to the muscles. Here, we show for the first time that during the initial phase of a maximal isometric explosive contraction, strength-trained individuals achieve higher levels of force and recruit motor units with greater conduction velocities.
Authors with CRIS profile
Involved external institutions
Università degli Studi di Brescia
Italy (IT)
Imperial College London / The Imperial College of Science, Technology and Medicine
United Kingdom (GB)
Università degli Studi di Roma "Foro Italico"
Italy (IT)
University of Birmingham
United Kingdom (GB)
Italy (IT)
Imperial College London / The Imperial College of Science, Technology and Medicine
United Kingdom (GB)
Università degli Studi di Roma "Foro Italico"
Italy (IT)
University of Birmingham
United Kingdom (GB)
How to cite
APA:
Del Vecchio, A., Negro, F., Falla, D., Bazzucchi, ., Farina, D., & Felici, F. (2018). Higher muscle fiber conduction velocity and early rate of torque development in chronically strength-trained individuals. Journal of Applied Physiology, 125(4), 1218-1226. https://doi.org/10.1152/japplphysiol.00025.2018
MLA:
Del Vecchio, Alessandro, et al. "Higher muscle fiber conduction velocity and early rate of torque development in chronically strength-trained individuals." Journal of Applied Physiology 125.4 (2018): 1218-1226.
BibTeX: Download