A problem of dehydration after a physical education class and habits of fluid intake with eighth-graders: Pilot study

Abstract

The aim of this paper was examine whether a physical education class can result in a level of dehydration which, according to a large number of authors, causes a drop in cognitive and working abilities. In the light of present knowledge, changes are notable even when the level of dehydration is 1-2% of the body mass loss. Besides, it was necessary to determine whether the respondents had problems caused by dehydration and their beverage consumption habits. The research included 28 eight-graders of a primary school in Belgrade, aged 14 to 15. The analyses of body structure, body mass and water content was done by the analyser 'InBody 370', followed by a physical education class when the station work was used as the organizational and methodical form. After the class, students' body mass was measured. The difference in body mass before and after the class represented the lost body fluid and was used to establish the percentage of dehydration. T-test for dependent samples showed a highly significant difference (p=0.000) in body mass before and after the class. In 86% of students, the percentage of dehydration was more than 1% of BM (the average value of 1.20%±0.22%). These results indicate that a physical education class can cause, in most of our students, the level of dehydration which, according to a large number of authors, can bring about the drop in various (mostly cognitive) abilities, which can lead to confusion during other classes after the physical education class. Results of the questionnaire showed that most of students (68%) had a fluid intake only when they feel thirsty, while 25% does not have any fluid intake during physical activity. The largest number of students (43%) feels the lack of concentration, fatigue, drowsiness and lethargy during classes following the physical education class. Sometimes this condition appears in 39% of students while only 18% of them do not feel any changes. Evidently, there is a problem of insufficient hydration in students. This problem should be solved in an organized way, at the school level. Students should gain knowledge about proper hydration. Another important factor is making water and other useful drinks available to students. The young should be encouraged to drink water more often during school and especially after the physical education class.