Clarification of a marathon-induced muscle soreness

• Project/Area Number: 18K17878
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: Josai University (2020); Sojo University (2018-2019)
• Principal Investigator: Keisuke Ishikura 城西大学, 経営学部, 教授 (90755258)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2020: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000); Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2018: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: 筋肉痛 / マラソンの壁 / ランニングペース / ランニングフォーム / メカニカルストレス / メタボリックストレス

Outline of Final Research Achievements

The purpose of this study was to investigate the relationships between the marathon induced muscle damage and metabolic and/or mechanical factors. Twenty-three healthy male non-professional runners ran at the full marathon with GPS watch to obtain the running parameters. We set video camera at the 8- and 38-kilometers points to record their running form.
Runners with reduced pace exhibited high muscle damage markers values, but not oxidative stress markers immediately after the marathon. Also, they were significantly decreased stride length and stride rate, hence they needed more steps than that maintained runners during whole the marathon. In addition, they had significant a large change of running form in 38 km point compared to that in the 8 km point, however, there were no relations between the change ratio and muscle damage values. These results suggest that marathon muscle damage is occurred by mechanical stress such as impact of a large steps rather than metabolic stress.

Academic Significance and Societal Importance of the Research Achievements

マラソン終盤のペースダウン，いわゆる「マラソンの壁」の要因として，古くからグリコーゲンの枯渇が指摘されているが，明確な根拠に乏しい．我々はこれまで，マラソン終盤の速度低下とマラソン誘発性筋損傷に関連があることを示してきた．本研究の結果から，マラソン誘発性の筋損傷には，酸化ストレス等のメタボリックストレスよりもステップ数の増加によるメカニカルストレスの影響が大きいことが明確になった．マラソン後半の失速を防ぐためには，ストライド長を維持するようにトレーニングすることが有効であると考えられる．

Research Products

• [Presentation] Runners with Reduced Pace Exhibit a Short Stride Length and High Muscle Damage Values of at the End of a Marathon (2019)
  • Author(s): Keisuke Ishikura, Katsuyuki Tokinoya, Yasuko Yoshida, Nanami Sekine, Keisei Kosaki, Shota Kumamoto, Seiji Maeda, Yoshiharu Nabekura, Kazuhiro Takekoshi
  • Organizer: European College of Sports Science
  • Int'l Joint Research
• [Presentation] フルマラソン時の歩調変化と筋損傷，速度低下の関係 (2019)
  • Author(s): 石倉恵介，時野谷勝幸，吉田保子，関根七海，小崎恵生，隈元翔太，前田清司，鍋倉賢治，竹越一博
  • Organizer: 第74回日本体力医学会大会
• [Presentation] フルマラソン前後の尿Cell-free DNA中のミトコンドリアDNA量の変化 (2019)
  • Author(s): 宍倉康浩，時野谷勝幸，吉田保子，関根七海，菅澤威仁，石倉恵介，小崎恵生，隈元翔太，前田清二，鍋倉賢治，竹越一博
  • Organizer: 第74回日本体力医学会大会
• [Presentation] 若年男性におけるフルマラソンが尿中L-FABPに与える影響 (2019)
  • Author(s): 隈元翔太，小﨑恵生，時野谷勝幸，菅谷健，石倉恵介，鍋倉賢治，竹越一博，前田清司
  • Organizer: 第74回日本体力医学会大会
• [Presentation] Runners with Reduced Pace Exhibit a Short Stride Length and High Muscle Damage Values of at the End of a Marathon (2019)
  • Author(s): Keisuke Ishikura
  • Organizer: European College Sports Science
  • Int'l Joint Research