The relationship between relaxation and rhythmic exercises with regard to functional neuroplasticity mechanism is a subject that has been studied in recent researches. The purpose of this study was to investigate the effect of rhythmic exercises on the depth of relaxation in national judo athletes. 30 male athletes of national judo team were randomly selected and divided into three groups: control, experimental 1 (relaxation) and experimental 2 (relaxation and rhythmic), 10 subjects each group. Data were obtained from a three-month period (two 6- weeks, the first 6-weeks relaxation for experimental 1 and 2 groups, the second 6-weeks relaxation and rhythmic exercises for experimental 1 and 2 groups and no exercise for control group) by EMG index. ANOVA and repeated measures tests were used to analyze the data. Findings showed a significant difference in the relaxation skill among groups. On the other hand, exercise periods increased relaxation and rhythmic exercises reinforced relaxation depth. Findings indicated that rhythmic exercises could improve relaxation and its depth.