The purposes of this study were to identify the difference among rating of perceived exertion (RPE) of marathon enthusiasts, their exercise commitment, exercise adherence according to personal characteristics, and to verify the causal relationship among the variables of exercise commitment, and exercise adherence. [METHODS] The data were collected with purposive sampling from 360 marathon enthusiasts who have completed a full course marathon more than one time. With exclusion of 20 subjects due to missing survey or insincere responses. The data from 340 participants were analyzed by one-way ANOVA using SPSS WIN 18.0.