目的：透過YO-YO有氧耐力測驗(YO-YO test)，探討呼吸肌引起急性疲勞對於耐力性運動表現及肺功能之影響，以提供訓練之生理檢測指標，提升運動員的運動表現。方法：研究對象以10名男性大專甲組田徑隊選手（無吸菸），經平衡次序分配，分別在兩次YO-YO test前施行呼吸肌疲勞(respiratory muscle fatigue, RMF)與無呼吸肌疲勞(none respiratory muscle fatigue, NRMF)（年齡為20±1.10歲；身高為174.9±5.17公分；體重65.5±4.61公斤；安靜心跳62±6.66次／分鐘），並於YO-YO test前、運動後與運動後15分鐘（血乳酸為運動後5分鐘）檢測其肺功能，包括第一秒用力吐氣量(Forced Expiratory Volume in 1. second, FEV1.0)、用力肺活量(Forced Vital Capacity, FVC)、第一秒用力吐氣量及用力肺活量的比值(FEV1.0/FVC)，以及最大呼吸肌力、血乳酸與運動後最大心跳率(HR(下標 max))。以重複量數二因子變異數分析，考驗兩次測驗中不同時段的FEV1.0、FVC、FEV1.0/FVC、最大呼吸肌肌力與血乳酸值，以t檢定檢驗兩次測驗中的最大心跳率、跑步距離間之差異。結果：兩組中FEV1.0/FVC、最大呼吸肌肌力及血乳酸值在運動後與運動後15分鐘中均無顯著差異，FVC、FEV1.0則有顯著差異；呼吸肌疲勞組之最大心跳率(190.0±6.83 vs. 195.4±5.94bpm)與跑步距離(1580±226.86 vs. 1760±298.14m)顯著低於無呼吸肌疲勞組(p<.05)。結論：呼吸肌引起急性疲勞會影響肺功能FVC與FEV1.0之數值，且呼吸肌呈現疲勞狀態時，會降低YO-YO有氧耐力測驗的跑步距離。因此，當運動員與教練在訓練或比賽時應注意呼吸肌肌力的狀態，以利運動員運動表現的提昇。

Purpose: The purpose of the study was to investigate the influence of respiratory resistance fatigue to endurance ability and YO-YO endurance test. Methods: Ten university track and field athletics, nonsmoking males were recruited to participate following tests by counter-balanced order. Every subject have to perform respiratory muscle fatigue (RMF) and none respiratory muscle fatigue (NRMF) (age 20±1.10 years, height 174.9±5.17 cm, weight 65.5±4.61 kg), examine their maximum inspiratory pressure (PImax), maximum expiratory pressure (PE(subscript max)), forced expiratory volume in 1 second (FEV1.0), forced vital capacity (FVC) and the value of FEV1.0/FVC within acute and 15 min following task failure and YO-YO test. Maximum heart rate (HR(subscript max)) and lactic acid were separate examine within pro-exercise acute and 5min later. A repeated measures analysis of two-way ANOVA was used to evaluate treatment (RMF and NRMF) and trail on each of the FEV1.0, FVC, FEV1.0/ FVC%, PI(subscript max), PE(subscript max) and lactic acid. RMF and NRMF were compared with the t-test in order to assess differences in HR(subscript max) and running distance. Results: FEV1.0/FVC, PImax, PEmax and lactic acid were no significantly difference in RMF and NRMF within immediately and 15 min following task failure, but FVC and FEV1.0 were significantly. The HR(subscript max) (190.0±6.83 vs. 195.4±5.94 bpm) and running distance (1580±226.86 vs. 1760±298.14 m) in RMF was significantly impair in NRMF. Conclusions: The findings in this study conclude that respiratory muscle fatigue will affect the lung function of FVC and FEV1.0, and respiratory muscle fatigue may impair the average running distance covered in YO-YO endurance test.