The purpose of this study is to conduct the examination of heart rate and speed variations with respect to the various interval trainings of swimming. One trained, one post-trained and one untrained swimmers were employed for this study. The experiment was conducted during the summer of 1968. The temperature of atomosphere varied from 30°C to 33°C and that of water from 27°C to 29°C.
The data of heart rate were obtained from the record of ECG. Two electrodes or ECG consisting of silver cups of 10mm in diameter were attached to the skin over sternum. In order to avoid mechanical and electrical disturbances, the electrodes were tightly fixed through the following procedures;
1) The electrodes were pasted on cleaned skin with ECG jelly.
2) The adhesive plaster was placed over the electrodes.
3) The adhesive plaster was coated with wax.
The wire of 20 meters was used to connect the electrodes and the recorder. On trial of interval training was consisted of two phases; 1) The active phaseTo swim 50 meters according to his swimming ability. 2) The rest phase.To take a 0, 5, 10, 20, 30, 45 or 60 seconds interval between each 50 meters swimming. Each trial of training was repeated ten times.
Results are as follows;
1) The longer the rest period is, the higher the swimming speed is.
2) All swimmers swim 50 meters at 60-80% of their maximum speed and the percent of the trained is higher than that of the untrained.
3) Maximum heart rates of the trained, the post-trained and the untrained during tenth swimming are 188, 180 and 173 respectively, which are the same in every trial.
4) Decreasing rates of heart rate during the rest period are 10 under in 5-10 seconds interval, 15-25 in 20-30 seconds interval and 20-50 in 45-60 seconds interval,