The effect of various intensity exercises (10-20-30) on performance endurance of kumite juniors in karate **Dr.Abdulaziz El-Sayed Mohamed El-Sayed Refaei This research aims to identify "the effect of various intensity exercises (10-20-30) on the development of performance endurance for kumite juniors in the sport of karate". Procedures: The researcher used the experimental approach, due to its suitability to the nature and procedures of the research, through the experimental design of one group by means of The two measurements (before and after). The research sample was chosen by the intentional method from the kumite players in the Egyptian national team for the sectors (Eastern sector), in the age group of (13, 14) years, and the results: Training 10-20-30 has a positive effect on the development of performance endurance among the kumite juniors in the sport of karate. An improvement in the telemetry of the pretest for the research sample individuals in the special physical tests and the performance endurance under study, and the percentages of improvement in the performance endurance variables Keywords 10-20-30 Training: It is a method derived from high-intensity interval training in which 10-second periods of speed are combined with 30 seconds of low-intensity running and 20 seconds of medium-intensity running, i.e. anaerobic work at near-maximal speed is combined with periods of aerobic work.