This study examined changes in attitude toward endurance running in senior high school students with different levels of physical fitness, and this study assessed mood and calculation functions of students before and after endurance running. The participants were 250 senior high school students (119 boys and 131 girls). Endurance running was practiced at a slow pace (slow jogging pace; heart rate: 30-35 [15s]; rate of perceived exertion (RPE): 11-13). Attitudes toward endurance running were assessed before and after the unit using a questionnaire. Attitudes toward endurance running, more specifically positivity and importance, were calculated in terms of a positive feeling score and cognitive score. In addition, negative attitudes toward endurance running were expressed as a negative feeling score. Changes in mood and calculation function were investigated in the participants and a control group. In the control group, comprising 75 boys and 41 girls, the changes of mood and calculation function were assessed before and after a health class. After the unit, the positive feeling and cognitive score increased significantly and the negative feeling score decreased significantly in both the lower and higher fitness groups. After endurance running, although levels of arousal in the control group were not increased in both boys and girls, arousal levels were increased significantly in both sexes in both the lower and higher fitness groups. The degree of mood change and the degree of attitude change were related significantly to the degree of change in perceived pleasure and the change in the positive feeling score for boys in the higher fitness group. Moreover, the degree of change in perceived pleasure and the degree of change in the positive and negative feeling scores were related significantly for girls in the lower fitness group. These results suggest that slow jogging in a unit, involving how students experience mood and calculation functions, leads to an increase in positive attitude toward endurance running. However, further investigation is necessary to examine the influence of slow jogging on mood and calculation functions, and the influence on attitude toward endurance running in this type of unit.