Over-Hydration Can Be Dangerous for Some

By Sondra Forsyth

Although it’s important for athletes to stay hydrated, it’s just as crucial not to drink too much water, according to new guidelines.

Overhydrating with water or sports drinks can lead to a condition called exercise-associated hyponatremia (EAH), said Mitchell Rosner, MD, a kidney specialist at the University of Virginia School of Medicine. Rosner, the chairman of the group that developed the guidelines, said EAH occurs when the body has too much water relative to its salt level. When the salt level in the blood falls too low, he added, it leads to significant neurological problems and can be fatal.

EAH has traditionally been associated with endurance sports like marathons and triathlons, but physicians are seeing the condition among participants in a wider range of athletics.

“We have documented at least 14 deaths [from EAH] since 1981, including two deaths last summer in young athletes playing football,” Rosner said. “The common feature in all cases is excessive water consumption during athletic events. This is driven by common misbeliefs that overhydration can improve performance and even prevent dehydration. It is worth noting that data demonstrates mild degrees of dehydration do not impair performance.”

The key to preventing EAH, Rosner said, is to let your body tell you when you need a drink.

“We recommend using your thirst as a guide,” he said. “If you drink when thirsty, you will not become hyponatremic and you will not suffer from significant dehydration.”

According to a news release from UVA, Rosner said this recommendation applies whether athletes are consuming water or sports drinks. “Overdrinking a sports beverage will still lead to hyponatremia,” he said. “They contain small amounts of sodium that may lessen the risk very slightly, but they are still mostly water.”

Initial EAH symptoms can include cloudy thinking, nausea and headaches, Rosner said. In severe cases, symptoms include seizures, severe confusion and coma. If coaches or parents suspect an athlete is suffering from EAH, the most important steps are to stop them from drinking and call for medical assistance.

For athletes with mild symptoms, limiting fluids and closely monitoring their condition will help them recover within a few hours, Rosner said, but more severe symptoms such as confusion require urgent medical attention.

The group’s guidelines were published in the Clinical Journal of Sports Medicine.