出版社：Instituto Brasileiro de Pesquisa e Ensino em Fisiologia do Exercício
摘要：Introduction: The practice of physical exercise causes physiological changes in the body and among them the increase in the rate of production of heat and sweating. The sweat production and subsequent evaporation thermoregulatory mechanism is more efficient, however, dehydration can compromise performance. There are several ways to evaluate the changes in hydration levels after the practice of physical exercise and among them, the measure of acute changes in body weight before and after exercise. Objective: To evaluate the changes in hydration levels of marathon runners after athletics. Materials and Methods: A total of 6 athletes athletics, the national average age of 29.67 years, fit the practice of competitive exercises. The study took place in two distinct stages one another in forty-five days. In each step, each of the athletes covered a distance of 20 km around an athletics track. In the first stage each athlete received every 4 kilometers of racing 200 milliliters of water to hydrate and the second stage was not allowed to hydrate athletes during the race. Body mass was measured before and immediately after exercise. Results: The results indicate that racing occurs without hydration leads to dehydration average of 2.14% of body weight. Discussion: It has been shown that fluid losses above 2% in relation to body mass can affect performance during sports. Conclusion: The practice of athletics with distance of 20 km leads to dehydration of 2.14% of body mass, which impairs the performance of the race. Key words: Exercise, Physical exercise, Body mass, Dehydration, Performance.
