DANGER OF TOO MUCH WATER

Physicians who automatically assume that a collapsed athlete is dehydrated could do serious, and possibly fatal harm by administering fluids, says a world-renowned expert in exercise science.

That's because a growing number of athletes actually drink too much fluid while exercising—putting themselves at risk for hyponatremia.

"These problems have arisen since the idea was promoted that you can't trust your thirst—that once you are thirsty, it is already too late . . . you are already dehydrated," said Dr. Timothy Noakes from the University of Cape Town, and the Sports Science Institute of South Africa, in a presentation at the meeting here.

"That's a myth—there's no evidence for it at all."

But he said race organizers, and many physicians, including the American College of Sports Medicine, have perpetuated this myth by issuing warnings about dehydration, setting up multiple water stations, and encouraging a high level of fluid intake during marathons and triathlons.

These measures are actually increasing the number of athletes who end up in the medical tents, he said. "At the Houston marathon they have water stations at every mile, and they also tell people to drink, and they have had 52 cases of hyponatremia in the past three years. Whereas in the Hawaii event, they only have water stations every 3 km and they actually advise runners not to drink excessively—and they have no hyponatremia," he said in an interview. Hyponatremia results when fluid overloading dilutes the serum sodium content, said Dr. Noakes.

This condition was unheard of in the marathon runners of the 1960s, who often drank as little as 100 mL of fluid an hour, he said. But today, some marathoners have been known to drink more than 1 L an hour. Initial signs of hyponatremia resemble those of concussion. The patient is disoriented and confused. But this condition can deteriorate rapidly.

According to a 2001 issue of Emergency Medicine, one study of 70 cases of exercise-related hyponatremia reported 49% had disorientation, 31% had seizures, 19% had pulmonary edema, 9% had coma and 3% had respiratory arrest. He said physicians who automatically assume a person is dehydrated could end up compounding the problem. "Unfortunately, giving fluids has simply become standard for physicians when they see any kind of exercise-related collapse. They don't examine the patient properly, they don't take a history, they don't do a clinical examination. They just simply stick in an I.V. and give more fluids."

In fact, physicians have contributed to at least four deaths since 1985—three in marathon runners, and one in an army recruit—because they administered fluids in patients who were already seriously hyponatremic, he said. He said he suspects less serious cases are consistently managed incorrectly in medical tents. Dr. Noakes said 80% of athletes who experience exercise-related collapse do so after finishing their event, due to postural hypotension. This is easily treated by lying them down with their legs elevated.

The remaining 20% collapse during their event—and this is due to either heatstroke or hyponatremia. "If you try having a conversation with them, you will know right away if they are confused—which means it is probably hypo-natremia."

Once hyponatremia is suspected, serum sodium should be measured. It is often about126 mmoles/L in a confused and disoriented hyponatremic patient (normal is 140 mmoles/L). The treatment for this level of hyponatremia is an intramuscular diuretic, with possibly some oral sodium, he said. "Within half an hour, they will start to pass urine and over the next few hours they will pass 5 L or 6 L." Patients who are unconscious, or who have had a convulsion need a high-concentration sodium drip, which should normalize their sodium levels within three hours.

Dr. Noakes (who receives funding from Cadbury, Schweppes and Energade), said physicians should make a point of reassuring their patients that dehydration is rarely a problem among athletes, as long as they drink when they are thirsty.

"At one time, humans had to chase down their protein in the heat of Africa. Of course, we have adapted to dealing with mild dehydration, or evolutionally we could not have survived."

ORDER L.A. DIET NOW !!
CLICK HERE !!
LOSE WEIGHT !!
ORDER L.A. DIET NOW !!

Lose Weight
With The LA Diet NOW! We know you will lose all the weight you want to lose.
Guaranteed!