When Sports Drinks Kill
For years now, we have been hearing the importance of hydration to avoid heat stroke during prolonged exercise in hot weather. Now, it turns out, too much hydration can kill you.
A study published in The New England Journal of Medicine should give people reason to rethink the wisdom of quaffing vast amount or water or sports drinks while exercising vigorously—at least if they are engaging in such endurance tests as a marathon. The study found that a marathon runner could dangerously dilute the blood with an overdose of liquids, risking a coma and even death. The problem has also been detected during long military maneuvers, extended bike rides and blistering hikes through the desert.
An article in The New York Times describes the slow and belated recognition of the problem. A South African expert who has been warning of the dangers for more than two decades said that he had not found a single case in which an athlete had died from dehydration in a competitive race, but that several people had sickened and died from drinking too much.
All too often, friends, coaches or emergency personnel assume that the problem is dehydration and administer yet more liquid, making the problem worse. The best treatment is a small amount of concentrated salt solution, given intravenously, to increase blood sodium concentrations. Sports drinks containing electrolytes may not help much as they are mostly liquid themselves.
In the 2006 Boston Marathon, for example, a 28-old woman found herself exhausted after running for five hours and gulping sports drinks along the way. Wrongly assuming that she was dehydrated, she chugged down a sports drink. She promptly collapsed and was later declared brain-dead. The concentration of salt in her blood was found to be lethally low.
Sports authorities have already issued warnings and tips to avoid excessive drinking. The solution is for overly eager endurance runners and hikers to forget the old mantra that they should drink—drink—drink. Too much liquid can be lethal. |
