Uncovering mechanisms of human circulatory control during exercise in the heat and building a basis for its applications

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K17582
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: Akita University
• Principal Investigator: Watanabe Kazuhito 秋田大学, 教育文化学部, 准教授 (70733145)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 暑熱ストレス / 心機能 / 循環反応 / 呼吸代謝応答 / 血液の運動エネルギー

Outline of Final Research Achievements

This study comprehensively investigated human circulatory responses and cardiac function and its relation to the other physiological responses during hyperthermia. Findings of this study suggest that local hyperthermia does not have profound effects on left ventricular function, whereas core hyperthermia enhances left ventricular systolic and diastolic functions. Alterations in pulmonary ventilation, systemic aerobic metabolism and blood volume may be involved in the enhanced LV functions during hyperthermia, but these responses are not obligatory for increasing cardiac output during hyperthermia. Furthermore, observations based on hydrodynamic approach suggest that local hyperthermia-induced selective augmentations in the velocity and kinetic energy of flowing blood appear to play an important role in the elevated cardiac output during hyperthermia.

Free Research Field

運動生理学

Academic Significance and Societal Importance of the Research Achievements

本研究では、運動や暑熱に関わる種々の生理応答に関して、高体温時の循環応答や心機能を中心とした統合的な検討を行い、呼吸、代謝、体液等の変化が心機能変化の誘因となり得ること、また、心拍出量応答は必ずしもそれらの要因と関連せず、末梢血の流速や運動エネルギーに強く影響を受ける可能性があることが示唆された。本研究の成果はヒトの高体温時の循環動態制御メカニズムの解明に寄与し、今後のさらなる知見の集積により運動や暑熱負荷の効果や安全性の向上に資する方法開発へ繋がると考えられる。