The aim of this study is to determine the need for rehydration of male students during the class of physical education and sport. The methodical-organizational form of work that was applied in class is named assault course. The activity was monitored with the use of pedometer, which registered a number of steps in class. Total number of monitored male subjects was 29. The following were analyzed: number of steps, body weight before and after the class and BTW worth before and after the class. After applying ANOVA analysis, the results showed registered weight loss, but without statistical significance. Besides weight loss, the BTW worth loss that was registered, had statistical significance. The analyzed BTW shows the need for an organized rehydrating of students. So, during the class of physical education and sport, it is necessary to provide the students with liquid. It is preferred to check the results of this study within other age categories or within different conditions of realization of teaching content.