The epidemiologic descriptions\u00a0 of a population show us the situation in which that population stands concerning its health aspects. In this specific case we can interpret its relation with their physical activities.\u00a0 The findings of this investigations can be utilize for the prevention and the control of some illnesses as well as the promotion of its health. In this investigation we pretend to find an epidemiologic description of the physical activity between a group of students of a mandatory high school of I.E.S. San Alberto Magno de Sabi\u00f1anigo, in Huesca Spain. We utilize the \u201cFour by one-day Physical Activity Questionnaire\u201d we collected an estimation of the total physical activity done by the students in and out of school activities, recorded in four registrations (surveys). We concluded that there was a high level of inactivity, it was much higher in the female population and it increase as the subject was older. It is very interesting to express the used of energy if we separated by the following activities: working, sports, and daily routine. On the other hand, we did not see a significant relation between the used of energy in other activities such as: smoking, watching television, and study. However, these activities do contribute to the understanding of the teenagers habits. With the collected data we can state that it is essential that students need to be conscious regarding their level of physical activity.<\/p>\n\n