Cardiovascular function and Lactic threshold were very important to all athletic, especially swimmer. The purpose of this study was to investigate the effects of 12 weeks circuit training to middle school's male swimmers Cardiovascular function and Lactic threshold. The subjects of this study were 8 male whose average age 15.3. They were voluntarily joined this program performing for one hour per day, 3 times a week over a period of 12 weeks.
For statistical analysis SPSS 10.0 statistic program has been used to calculate average and standard variation and the independent t-test has been applied to determine statistical significance of the data, accepting level for all significances was above α=.05. The results of this study were as follows.
In conclusion, circuit training increase their cardiovascular endurance and decrease blood lactic acid of middle school's male swimmers.