In this paper we reported an investigation of exercise intensity and validity of method for athletes’ training in case of some interval training based on an empirical for junior elite swimmers from point of blood lactate. The subjects were ten junior swimmers designated to train by a local federation in Nigata. Six swimmers specialized in a short distance swimming and four swimmers specialized in 400 m individual medley. All subjects were measured for their blood lactate and heart rate immediately after swimming, velocity and the necessary time of swimming. The results of this experiment led us to conclude 1) In the case of this examination of repetition training of 100 m free style, it is though that a buffering of blood lactate can not compensate for a producing of that, and because of oxygen debt for respiratory muscle, anaerobic metabolism may be participated. 2) In the case of 400 m individual medley, it is thought that 400 m individual medley have been demanded aerobic work capacity in comparison with 100 m crawl stroke
