This article was originally published in the CrossFit Journal. Summer is just about here, and with that comes warmer temperatures. We've been hitting the mid (and even high) 80's already this week, and it's only May!
There are always extra considerations to take when working out in the heat. This is an interesting article about hydration that presents new information on how much fluid an athlete actually needs when exercising, and how excess fluid consumption can actually be extremely harmful. Read on…
By Hilary Achauer
Dr. Tamara Hew-Butler, a devoted marathon runner and sports-medicine podiatrist, was working in the medical tent at the 2000 Houston Marathon in Houston, Texas.
“It was hot that day,” Hew-Butler said, “and all these runners came (into the tent) and collapsed.”
Hew-Butler and her colleagues knew exactly what to do. Assuming dehydration, the medical aides started IVs for the collapsed runners. Then something strange happened. Instead of getting better, many of the runners got sicker. The medical workers continued to administer intravenous fluids.
“We were giving more IVs until four runners had seizures. They were taken to the hospital and were in comas for a week. They almost died,” Hew-Butler said.
The runners all suffered from exercise-associated hyponatremia (EAH). Hyponatremia occurs when sodium levels in the blood fall below 135 milliequivalents per liter (mEq/L; in international units, this is expressed as millimoles per liter, or mmol/L).
A normal blood-sodium range is between 135 and 145 mEq/L. Hyponatremia can cause mild symptoms such as irritability and fatigue or more extreme symptoms including nausea, vomiting, seizures and comas. Brain swelling—exercise-associated hyponatremic encephalopathy (EAHE)—can cause death.
Most of the current hydration guidelines—including pre-hydration and drinking 8 oz. of fluids every 20 minutes while exercising—are not only unnecessary but can also be life-threatening for some people. In “Waterlogged: The Serious Problem of Overhydration in Endurance Sports,” Dr. Tim Noakes examined the problem in detail over 429 pages. He graphed over 1,600 cases of EAH and EAHE from 1981 to 2009, including a dozen fatalities. Noakes believes these conditions are entirely preventable. The solution: Athletes should drink only to thirst. But instead athletes followed hydration guidelines that either put them in the hospital or the grave.
Source: CrossFit Journal