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Via Christi expert to athletes: Drink only when you are thirsty


For athletes, drinking water is especially important. But did you know they can drink too much water? It’s a condition called exercise-associated hyponatremia (EAH) or “water toxication.” This is when the body’s blood sodium level drops as a result of over hydration.

Previous and problematic advice to those who participate in sports and other activities was to drink before becoming thirsty. Experts – including Douglas Lewis, MD, a faculty member at the Ascension Via Christi Family Medicine Residency Program  now say that EAH can be avoided if athletes drink only when they are thirsty. 

"Our major goal is to re-educate the public on the hazards of drinking beyond level of thirst during exercise," Dr. Lewis says.

New recommendations focusing on the prevention of EAH were recently approved by a panel at the Third International Exercise-Associated Hyponatremia Consensus Development Conference. It was published in the Clinical Journal of Sport Medicine and co-authored by Dr. Lewis. 

An athlete is at risk for EAH when they take in so many fluids that their body can’t expel them by sweating and urinating. The surplus of fluid then builds up in their body and waters down its blood sodium level, causing problems with normal functions.

Blood sodium levels can drop during or up to 24 hours after exercising or sports activity. Especially before the drop in sodium level becomes too severe, EAH may have no or only mild symptoms. These include:

  • Headache
  • Vomiting 
  • Confusion or seizures, resulting from swelling of the brain (cerebral edema)

Should they appear, ignoring the symptoms without seeking immediate treatment can be fatal. Prevention is easy, however.

According to the panel, "The safest individualized hydration strategy before, during and immediately following exercise is to drink palatable fluids when thirsty."

In a press release, author Tamara Hew-Butler of Oakland University and co-author Dr. Lewis say balanced hydration before, during and immediately following exercise would prevent the potentially fatal consequences of “forced hydration” practices.
"Every single EAH death is tragic and preventable, if we just listen to our bodies and let go of the pervasive advice that if a little fluid is good, then more fluid must be better," they said.