Researchh Of Cerebral Oxyrenation During Incremental Exercise By NIRS

Purpose: The activities including physical, cognitive, emotion are all controlled by thenervous system. And the brain is the highest level of the nervous system. Brain functionactive induce brain hemodynamic change. Near infrared spectrum can real-time andcontinuous monitor the change of brain hemodynamic. The purpose of this study is toobserve brain oxygenation changes during incremental exercise and to research therelationship between the changes and exercise fatigue as well as the correlation betweenphysiological and biochemical indexes through the observation of the change of brainhemodynamic.Methods:13male participants were recruited from the Post Education Department at theCapital Institute of Physical Education. The exercise session then commenced at a poweroutput of0Watt, with the exercise load increased by25W every2minutes until volitionalexhaustion occurred. Simultaneously, for the entire duration of cycling exercise,measurements of pulse and saturation of pulse oxymora were obtained every30seconds;blood samples were drawn before the last minute of each intensity increment; ratings ofperceived exertion (RPE) were obtained at rest and at the end of each intensity increment.To avoid artificial signals for NIRS monitoring, the subjects were asked to keep their headon the headrest during cycling. After volitional exhaustion occurred, the participants weregiven a cool down period of exercise (25W,5minutes).Results:1There were significantly changes in△HbO2between CBVT and Rest stage, LTand CBVT stage, CBVH and LT stage. There were similar characteristics of the changes in△tHb.△HbO2began to decrease gradually before all-out.2The changes in blood lacticacid, pulse and RPE were significant correlated during incremental exercise.Conclusion:1. NIRS can be used to monitor the changes of brain hemodynamic duringincremental exercise.2.The decline of△HbO2occurred before exhaustion and this may beone of the factors lead to fatigue.