Contralateral repeated bout effect after eccentric exercise on muscular activation
Contralateral repeated bout effect after eccentric exercise on muscular activation
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DOI：
10.1007/s00421-018-3933-9
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发表时间：
2018-09-01
影响因子：
3
通讯作者：
Ochi, Eisuke
中科院分区：
文献类型：
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作者：
Tsuchiya, Yosuke;Nakazato, Koichi;Ochi, Eisuke
本研究旨在利用磁共振成像（MRI）的横向弛豫时间（T2）研究对侧和同侧屈肘肌离心收缩（ECCs）对肌纤维激活的影响。最初，所有受试者在一个组（ECC 1）进行了30次ECC。2周后，他们对同侧臂（IL-RBE）和对侧臂（CL-RBE）进行了30次ECC。在ECC之前、之后即刻、1、2、3和5天测量最大自主等长收缩（MVC）扭矩、运动范围（ROM）、肌肉酸痛、横截面积（CSA）和T2。与ECC 1相比，IL-RBE和CL-RBE抑制了MVC扭矩的损失、有限的ROM、以及发展的肌肉酸痛和CSA（p <0. 05）。急性T2是肌纤维活化的指标，IL-RBE和CL-RBE的急性T2比ECC 1长（p < 0.05）。另外，在其他测量中，IL-RBE和CL-RBE之间没有观察到显著差异。我们的结果表明，ECCs的CL-RBE的机制之一是肌纤维激活的增加。此外，在未经训练的年轻男性中，CL-RBE的保护作用大小与IL-RBE相似。
The purpose of this study was to investigate the contralateral and ipsilateral repeated bout effects of eccentric contractions (ECCs) on muscle fiber activation using transverse relaxation time (T2) of magnetic resonance imaging (MRI).Eleven men (22.3 +/- 2.9 years) performed two bouts of 30 maximal ECCs of the elbow flexors spaced 2 weeks apart. Initially, all subjects performed 30 ECCs for one arm (ECC1). After 2 weeks, they performed 30 ECCs for both ipsilateral arm (IL-RBE) and contralateral arm (CL-RBE). Measurements were maximal voluntary isometric contraction (MVC) torque, range of motion (ROM), muscle soreness, cross-sectional area (CSA), and T2 at before, immediately after, 1, 2, 3, and 5 days after ECCs.The loss of MVC torque, limited ROM, and developed muscle soreness and CSA were inhibited for IL-RBE and CL-RBE compared with ECC1 (p < 0.05). The acute T2, which is an indicator of the activation of muscle fibers, was longer for IL-RBE and CL-RBE than ECC1 (p < 0.05). Otherwise, no significant difference between IL-RBE and CL-RBE was observed in other measurements.Our results suggest that one of the mechanisms for CL-RBE of ECCs is the increase in muscle fiber activation. In addition, the magnitude of protective effect for CL-RBE was similar to the IL-RBE in untrained young men.