2013 Fiscal Year Final Research Report

Mechanism of the effort-induced hyperventilation during intense exercise

Research Project

Project/Area Number	24700606
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Physical education
Research Institution	Hokkaido University
Principal Investigator	YUNOKI TAKAHIRO 北海道大学, 教育学研究科(研究院), 准教授 (00352500)
Project Period (FY)	2012-04-01 – 2014-03-31
Keywords	運動 / 呼吸
Research Abstract	This study determined the mechanism of the effort-induced hyperventilation during intense exercise (IE). Integrated EMG (iEMG) in the active muscle (AM) decreases during IE with reduced muscle glycogen. The first experiment showed that the iEMG decrement was suppressed by carbohydrate supplementation, indicating that the central command (CC) to the AM is decreased when effort sense is increased, while the CC decrement is suppressed when the increase in effort sense is avoided. Thus, this suggests the possibility that the effort-induced hyperventilation is associated with decrease in excitability of the primary motor cortex. Although this association was determined by using TMS, further analysis was needed to verify the above hypothesis. The last experiment showed that ventilation with breathing effort augments the corticospinal excitability of AM, suggesting that hyperventilation during IE have a role of supporting muscle activity by a mechanism differing from a homeostatic mechanism.