Within the limits of the research sample, its objectives and hypotheses, and within the limits of the study and its results, the researchers were able to reach the following conclusions: 1- 10-20-30 training has a positive effect on the development of critical speed, physical variables (transitional speed, speed endurance and muscular capacity) and physiological variables (maximum oxygen consumption, maximum aerobic speed, maximum and average anaerobic capacity and fatigue index) and the digital level of the 800-meter race. 2- There were statistically significant differences between the experimental and control groups in the post-measurement of critical speed, physical variables (transitional speed, speed endurance and muscular capacity) and physiological variables (maximum oxygen consumption, maximum aerobic speed, maximum and average anaerobic capacity and fatigue index) and the digital level of the 800-meter race in favor of the experimental group.