Athletes prepare for the 100 meters men's race at the IAAF World Challenge Ostrava Golden Spike meeting in Ostrava May 31, 2011.
Drinking enough water is good for health, but drinking too much can be fatal, health experts say. Reuters

Health experts often advise people to keep hydrated by drinking plenty of water. However, recent research claims that overrehydration is more dangerous than dehydration. Previous research claimed that people should not wait until they feel thirsty to drink water. However, the latest study clarifies that this advice is meant only for people who sweat extensively or more frequently, such as athletes and workers who do heavy manual labor.

Researchers believe that some people misinterpret the advice and end up drinking water in excessive amounts -- sometimes with disastrous results. According to the researchers, a constant intake of fluids during an athletic event or while doing a strenuous physical activity is not always necessary.

“The risks associated with dehydration are small,” explains Dr. James Winger of the Loyola University Medical Center. “No one has died on sports fields from dehydration, and the adverse effects of mild dehydration are questionable. But athletes, on rare occasions, have died from overhydration.”

According to the researchers, drinking too much fluid can lead to confusion, nausea and lightheadedness. In rare cases, it may even lead to a cerebral edema, in which a part of brain swells due to retention of excess water. A condition called exercise-associated hyponatremia (EAH) is believed to have killed more than 14 athletes in the past, who died because of drinking excess water during exercise.

The complete study has been published in the Clinical Journal of Sports Medicine.