本研究旨在探討游泳選手從事有氧耐力訓練時，使用臨界負荷(Critical Power; CP)概念作爲訓練時的強度依據，對於游泳選手的成績與血乳酸代謝有何影響。本研究以十二名臺中市全國運動會游泳代表隊選手爲研究對象，每位受試者首先需接受臨界速度(Critical Velocity; CV)與400m捷泳的最大努力運動測試，確認每位受試者游泳的CV強度後，依據該強度安排受試者接受10週的CV強度有氧耐力訓練，經過10週CV強度有氧耐力訓練後，安排受試者再一次接受CV與400m捷泳的最大努力運動測試，運動測驗過後詳細紀錄下每位受試者的成績、血乳酸(LA)與CV值變化情形。研究結果顯示，經過10週的CV強度訓練後，除了受試者的50m捷泳成績與訓練前沒有顯著差異外，其他項目成績都有顯著的進步，而受試者的CV與血乳酸代謝在訓練過後也都有明顯的提昇，效果皆達顯著水準，顯示臨界速度確實可作爲訓練時的強度依據。

The purpose of this study is to investigate how influence on swimmer's achievement and effect of Lactic Acid (LA) using Critical Power (CP) as the strength of training when the swimmer engages in aerobic endurance exercise training. The target interviewees in this study were 12 swimming representative team players from National Taichung Athletic Meet and every interviewee has to receive the Critical Velocity (CV) and test with 400 meters freestyle under maximum efforts. After confirming each swimmer's intensity of CV, they start to receive 10-week CV aerobic training according to different intensity. After 10-week CV aerobic training, every interviewee has to receive CV and test with 400 meters freestyle under maximum efforts again. After exercise examining, it is clear to record each interviewee's achievement, and change of LA and CV value. The research result indicates each grade result has obviously improved after 10-week CV intensive training except 50 meters freestyle training and also the swimmer's CV and LA value is rising apparently to achieve standard after training which means the CP can be a basis of intensity when training.