The researcher assumed that there are statistically significant differences in the results of the lactic acid index between the pre and post-tests and that there are statistically significant differences between the lactic acid index and achievement.

The researcher used the experimental method in the one-group method due to its suitability to the nature of the research, and the research community was determined by the players of the Missan Governorate team for the 800-meter running event for the youth category for the season 2021, whose number is (6) players. The duration of the curriculum is (12) weeks, at the rate of (2) two units per week, as the total number of units of the training curriculum is (24) units.