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Muscle conduction velocity, strength, neural activity, and morphological changes after eccentric and concentric training
Author(s) -
Cadore E. L.,
GonzálezIzal M.,
Pallarés J. G.,
RodriguezFalces J.,
Häkkinen K.,
Kraemer W. J.,
Pinto R. S.,
Izquierdo M.
Publication year - 2014
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12186
Subject(s) - concentric , isometric exercise , eccentric , medicine , ultrasonography , electromyography , eccentric training , anatomy , physical medicine and rehabilitation , physical therapy , mathematics , surgery , physics , geometry , quantum mechanics
This study compared the effects of concentric and eccentric training on neuromuscular adaptations in young subjects. Twenty‐two men and women were assigned to one of two groups: concentric ( CON , n = 11) and eccentric ( ECC , n = 11) training. Training consisted of 6 weeks of isokinetic exercise, performed twice weekly, starting with two sets of eight repetitions, and progressing to five sets of 10 repetitions. Subjects were tested in strength variables [concentric, eccentric, and isometric peak torque (PT), and rate of force development ( RFD )], muscle conduction velocity ( CV ), neuromuscular activity, vastus lateralis ( VL ) muscle thickness, and echo intensity as determined by ultrasonography. There were similar increases in the concentric and eccentric PTs in both the CON and ECC groups ( P < 0.01), but only the ECC group showed an increase in isometric PT ( P < 0.001). Similarly, both groups exhibited increased VL muscle thickness, CV , and RFD , and reduced VL echo intensity ( P < 0.05). Significant correlations were observed among the relative changes in the neuromuscular outcomes and training variables (e.g., total work, average PT ) ( r = 0.68–0.75, P < 0.05). The results showed that both training types similarly improved dynamic PT , CV , RFD , and muscle thickness and quality during the early weeks of training.