The effect of unilateral eccentric exercise and training on the contralateral side

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K17829
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: Teikyo Heisei University
• Principal Investigator: Tsuchiya Yosuke 帝京平成大学, 現代ライフ学部, 講師 (20614473)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 繰り返し効果 / 筋損傷 / 横緩和時間 / 磁気共鳴映像法 / 運動単位 / 神経適応

Outline of Final Research Achievements

A bout of maximal eccentric contractions (ECCs) provides a protective effect against muscle damage in subsequent bouts of the same exercise performed over several weeks (repeated bout effect). Recent some studies have shown that the initial bout of maximal ECCs is responsible for conferring protective effects upon the contralateral limb (CL-RBE). The purpose of this study was to investigate the contralateral and ipsilateral repeated bout effects of ECCs on muscle fiber activation using transverse relaxation time (T2) of magnetic resonance imaging (MRI). The acute T2, which is an indicator of the activation of muscle fibers, was larger for CL-RBE than ECCs of the first bout. Our results suggest that one of mechanisms for CL-RBE of ECCs is the increase in muscle fiber activation.

Free Research Field

スポーツ生理学

Academic Significance and Societal Importance of the Research Achievements

本研究では、対側性の繰り返し現象を神経系の適応の観点で、メカニズムを解明するという点において独自性を有している。繰り返し効果のメカニズムを検証した研究は複数報告されているものの、磁気共鳴画像法の横緩和時間を用いて、筋線維の動員を評価した検討はない。これらの検証によって得られた本研究の結果は、片側性の筋運動の反対側への効果メカニズムにとどまらず、スポーツや運動で受傷した際に余儀なくされるギプス固定や不活動の後のリハビリテーションに応用可能なデータを提示するものと考える。