The research aims to know the effect of CrossFit training for the age group for young people under 13 years of age on the physical effort represented in (lactic acid rate in the blood during rest - the rate of lactic acid in the blood after the effort), the special endurance represented by (performance endurance - strength endurance - speed endurance). Some of the offensive technique skills are represented in (OH Gary + Tani Atoshi - Tai Atoshi + OH Gary - H Mata + OH Gary - H Mata + Ko H Gary - Hirai Joshi + The research community and sample were chosen in a deliberate way from the players of the Sharkia Sports Club in Zagazig for juniors (under 13 years old) for the 2019/2020 sports season. The community included (34) players, (4) players were excluded for irregular training, and then (8) were withdrawn. Players for the exploratory sample, so that the strength of the basic research sample becomes (22) players. The researcher used the experimental method using the experimental design for one experimental group due to its relevance to the nature of this study. The use of CrossFit training led to a decrease in the concentration of lactic acid in the blood of judokas, and the use of CrossFit training led to an improvement in the special endurance, offensive technique level of judokas.or Soto Gari - Tsuri Kumi Joshi + OH Gary - Heza Gurma + Hari Joshi