Yes, You CAN Drink Too Much Water!

You've always been told "Drink plenty of water" especially if you exercise, and You? You love your exercise. In fact, you're unstoppable, no matter what the weather. Hey, you know what to do: Dress to sweat and drink lots of water — before, during and after your workout. No dehydration for you.

Your motto is drink, drink, drink and then drink some more.

But what if we told you all that H20 could be killing you?

Too much water can do just that, according to Albert Siegel, M.D., chief of internal medicine at McLean Hospital in Belmont, Mass., and assistant professor of clinical medicine at Harvard Medical School in Boston.

Water intoxication cases on the rise
Water intoxication (called hyponatremia) — once rare — is occurring more frequently as more recreational walkers, runners, cyclists and orienteering enthusiasts conquer marathons, 24-hour mountain bike races and other long-distance events. At greatest risk are those pounding the pavement for more than four hours and, in the process, drinking so much water and sports drink that they dangerously dilute the sodium concentration in their blood, jeopardizing vital body functions, Siegel says.

"It's a real problem and it's more dangerous than dehydration," he says. "We're seeing [varying degrees] of water intoxication in 10 to 15 percent of marathon participants." Several runners have died from hyponatremia in recent years, said he adds, including a 22-year old fitness trainer and first-time marathoner who died after completing the London Marathon in April.

Signs, symptoms and how to help hyponatremia victims

You may have even witnessed hyponatremia: a runner stumbling along the race course, acting strange, complaining of nausea, headache or muscle cramps. You may have concluded the athlete was dehydrated — a reasonable assumption since the signs and symptoms of the two conditions are similar.

For this reason, stopping to give first aid to an athlete in distress gets tricky.

"If you're out on a long training run and someone on the course shows signs of hyponatremia — confusion, difficulty breathing, nausea, vomiting — you need to get him to a hospital," said Riva Rahl, M.D., director of the Cooper Wellness Program at the Cooper Clinic in Dallas. "There’s nothing you can do [on the scene] for overhydration, but the hospital can treat him with a concentrated saline solution IV," Rahl says.

"You have to prevent hyponatremia," says Ken Phillips, chief of emergency services at Grand Canyon National Park in Arizona. "We see hyponatremia quite frequently here. People are exerting themselves in a hot environment and replacing what they sweat off with straight water," while they should be rehydrating fluids containing electrolytes and eating salty foods, Phillips says.

Because water intoxication looks so much like heat exhaustion in its early stages and can mimic heat stroke once seizures begin, emergency medical rangers at the Grand Canyon carry portable equipment to test the blood sodium concentration of fallen hikers before giving aid. Patients determined to be water intoxicated are taken by helicopter to hospitals for intravenous (IV) treatments, he adds.

"Unfortunately, you can't put salt back into someone once they’ve reached an altered level of consciousness or are critical. They need to go to the hospital," Phillips says. "We can fix dehydration; overhydration we can’t fix."

If you haven't been able to prevent it from happening, he says there are a few things you can do while waiting for help to arrive:

- Sit the person up — to ease intracranial pressure.
- Watch for vomit — aspirating vomit can kill.
- Increase sodium levels slowly — if possible give salt, chips, concentrated bullion. (Maybe it will help.)

- Keep the person calm — anxiety may interfere with breathing.
- Watch for seizures — if the person has a seizure, rest him gently on his side and remove hard objects from the immediate area. Don't put anything in his mouth.

To drink or not to drink?

The take-home message: Drink when you are thirsty and stay ahead of the sodium curve. During an endurance event, eat something salty like chips or pretzels as you drink, or bring along salt tablets to swallow with your regular water. Sports drinks alone won’t replenish your sodium if you have been exercising for many hours in hot conditions.

The USA Track & Field organization, which governs track-and-field events, now advises athletes to use thirst as a guide for fluid replacement. The International Marathon Medical Directors Association now advises drinking no more than about 12 to 25 ounces of fluid an hour during long-distance events.