背景:中樞與周邊疲勞是造成遞增負荷運動測驗(GXT)力竭的主因。近紅外線光譜儀(NIRS)已被廣泛地應用於測量大腦與肌肉氧飽和度,用以觀察中樞與周邊疲勞的變化。目的:透過整理以NIRS觀察GXT的中樞與周邊氧飽和度變化情形之文獻,探討中樞與周邊調節的可能機制。方法:蒐集與分析相關文獻。結果:當運動強度在達到第二換氣閾值(VT2)之前,大腦氧飽和度隨強度增加而上升,肌肉部分則隨之下降;當運動強度超過VT2之後,大腦與肌肉的氧飽和度則持續下降。結語:大腦與肌肉氧飽和度會受到中樞的調節,亦即在高強度運動時,大腦氧飽和度的降低,會讓中樞產生疲勞感並減少神經肌肉的招募,而肌肉氧飽和度的持續下降,最終導致運動表現的下降或停止。
Background: The central and peripheral fatigue both are the primary factors of all-out phenomenon during the graded exercise test (GXT). Near-infrared spectroscopy (NIRS) is widely used to measure the cerebral and muscular oxygenation, and to evaluate the changes in central and peripheral fatigues. Purpose: To investigate the possible mechanism for regulating the central peripheral system through reviewing previous studies that used the NIRS to assess the cerebral and muscular oxygenation. Methods: Review and analyze previous studies. Results: When the intensity is lower than the second ventilatory threshold (VT2), cerebral oxygenation progressively increases and muscular oxygenation gradually decreases after the beginning of exercise. However, when the intensity is higher than the VT2, the cerebral and muscular oxygenation both gradually decreases till the end of GXT. Summary: The cerebral and muscular oxygenation may be regulated by central governor mechanism. The decreases in cerebral oxygenation during the high intensity exercise might induce the feeling of central fatigue and reduce neuromuscular recruitments, and then continuously decrease the muscular oxygenation, and thus limiting or stopping the exercise.