Over hydration (drinking too much water) is killing our athletes–from marathon runners to high school football players to Bikram yoga. This is the consensus statement of 17 international scientist which was recently published in the British Journal of Sports Medicine . Sporting culture continues to embrace hyper-hydration but this statement should stand out as a stark warning.
The dangers of hyponatremia (dangerously low levels of sodium), which is the result of drinking too much water, have been known for a very long time. An important fact here–low sodium is very rarely caused by not taking in enough sodium.
What Happens with Over Hydration?
The first symptoms are usually headache, nausea and vomiting. Shortly thereafter, one may see memory loss, confusion followed by lethargy. Muscle cramping and spasm may be described and eventually seizures, coma and death.
Who is at Risk of Over Hydration?
Physicians have known for a long time that marathon runners were at risk for over hydrating. Specifically, people who sweat less, or run more slowly, do not need to drink as much as the runners at the front of the pack–but they often do. But now, things are changing and examples of exercise-associated hyponatremia has been reported in everything from Bikram yoga to high school football.
Players, coaches and the rest of us often see muscle cramping and spasm as a sign of dehydration and so the advice is “drink more water”, which leads to worsening over hydration.
In 2014, two otherwise healthy 17 year old high school football players died of exercise associated hyponatremia or over hydration. As a result, USA Football published a post stating,”While concerns regarding dehydration and exertional heat stroke are valid, current recommended safe drinking guidelines and advising athletes to drink to the dictates of thirst take all of these risks into account, such that extreme hydration is never warranted and the adverse effects can be avoided.”
How to Avoid Exercise-Associated Hyponatremia
Exercise associated hyponatremia is always preventable. The difficulty is in balancing under-hydration (not drinking enough water), which can lead to heat stroke (for more on heat-stroke, see Evolve Medical Clinic’s post).
It is also important to note that the 17 year old Georgia football player who died in August 2014, had died
after drinking too much Gatorade. In other words, drinking sports drinks or “balanced” drinks with electrolytes will not prevent this problem.
According to the authors of the Consensus Statement, to prevent EAH endurance athletes should drink when thirsty.
“Using the innate thirst mechanism to guide fluid consumption is a strategy that should limit drinking in excess and developing hyponatremia while providing sufficient fluid to prevent excessive dehydration.”
Or to summarize it all: Obey your thirst.