Runners or any long-distance athletes who drink too much water during a race could put themselves at jeopardy for developing hyponatremia, a condition marked by a loss in the body's sodium content that can result in physical symptoms such as lethargy, disorientation, seizures and even respiratory distress.
"Those who are running to finish the race very fast do not have time to drink a lot of water along the way,” said Dr. Benjamin Levine, professor of internal medicine at UT Southwestern. "Those who are not running the race competitively tend to stop at every water station and take a drink. Over the course of a long race, they can dilute themselves.”
In addition, popular sports drinks include not always enough sodium to offset the body's loss of the mineral during exercise. The drinks often carry more water with smaller concentrations of salts than are normally found in the human body. Therefore, they do not replace salts adequately, said Dr. Levine, medical director of the Institute for Exercise and Environmental Medicine, a collaboration between UT Southwestern and Presbyterian Hospital of Dallas.
The study evaluates the blood concentration of sodium in runners both before and after a long race and examines their risk factors for developing hyponatremia. It recommends individualised fluid-replacement consumption by all competing athletes.
"Researchers of the study found a surprisingly large number of runners had actually gained weight during the race and their sodium concentrations were very low - some were dangerously low,” Dr. Levine said.
"All serious distance athletes should find out what their rate of fluid loss is and individualise their fluid intake prior to a distance event,” Dr. Levine said. "It is also good to accept some mild dehydration during a long race. There are plenty of Web sites available now that show how to customise your fluid intake.”
MEDICA.de; Source: UT Southwestern Medical Center