The study aims to identify the relationship between MCT1 gene and some physiological variables and the level of lactic acid after effort and until fatigue in order to identify the differences between the performance under effort and until fatigue for juniors under the study.
Study sample included 10  juniors from Benha sports club at age stage  from 12 to 16 years old .The  study used  the experimental method, The most important results  indicated that there are statistically significant differences between MCT1 gene concentration  under  effort and until fatigue, as well as the existence of relationship between MCT1 gene concentration and between and some physiological variables, while there was no relationship between the concentration of the gene and the level of lactic acid under effort, while there was a relationship between gene concentration and  performance until  fatigue