北海道大学大学院教育学研究院紀要 = Bulletin of Faculty of Education, Hokkaido University;第140号

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Influence of exercise intensity on dynamics of blood volume caused by muscle pump action

Chen, Lu;Hatano, Kei;Yunoki, Takahiro;Yano, Tokuo

Permalink : http://hdl.handle.net/2115/86175
JaLCDOI : 10.14943/b.edu.140.191
KEYWORDS : total hemoglobin concentration;incremental exercise;exercise intensity;muscle blood volume;総ヘモグロビン濃度;漸増負荷運動;運動強度;筋血液量

Abstract

The aim of this study was to determine whether total hemoglobin concentration (cHb) in the quadriceps muscle measured by near-infrared spectroscopy (NIRS) varies depending on the muscle pump action accompanying the muscle contraction during incremental exercise and whether this variation is enhanced by exercise intensity. The subjects of this study were 6 healthy adult males. After 5 minutes of rest, exercise intensity was gradually increased at a rate of 50 w per 5 min from 50 w to 200 w. From 200 w, the work rate was increased by 20 w per one min. The subjects continued to exercise until a pedal rotation speed of 60 rpm could not be maintained (exhaustion). cHb in the quadriceps muscle was measured continuously at 20 Hz during exercise. A decrease in cHb was observed in the first pedaling after starting the exercise. The dynamics of cHb during one pedaling was divided into three phases: the rapid decline (phase I), the rapid rise (phase II), and the transition phase from phase II to the next phase I (phase III). The height between the lowest value and the highest value of cHb during one cycle was defined as cHb amplitude. There was no significant change in amplitude of cHb with increasing exercise intensity. Also, each duration of cHb phases did not significantly change with increasing exercise intensity. Therefore, it was concluded that there is a muscle pumping effect on cHb dynamics during incremental exercise. However, it seemed that the defined amplitude for the cHb dynamics did not increase with increasing exercise intensity.

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