The aim of the research was to try to identify The effect of CrossFit exercises on improving some physical and biomechanical variables as afunction of the electrical muscle activity of block players in volleyball. The research sample was selected deliberately from players registered with the Egyptian Volleyball Federation, where the number of the sample was (10) players. The researchers used the experimental approach using the one-group experimental design with the pre- and post-measurements for its relevance to the nature and purpose of the research. The most important results were the proposed training program using CrossFit exercises, which led to the improvement of physical, biomechanical and muscular variables. The most important recommendations were to use the proposed training program for CrossFit exercises to contribute to improving the physical, biomechanical and muscular variables. also similar studies should be conducted on other skills and different age groups for players using CrossFit exercises, application of the program Exercises proposed using CrossFit exercises in various sports activities to improve athletes' performance and reach higher levels. Keywords: CrossFit exercises - electrical muscle activity - block