I don't see a reason why only plain water would cause hyponatremia, although practically speaking, plain water is probably the only low-sodium beverage that people would commonly guzzle in large enough volumes to cause dilutional hyponatremia. It's the effect on serum sodium levels that matters, not how you get there. There are multiple mechanisms that can lead to hyponatremia.

Guzzle enough decaf coffee and I see no reason why that could not also cause hyponatremia. Switch to the caffeinated version and then you will induce diuresis and could possibly trigger a sodium imbalance that way, too. Well, on a hot summer day, someone could conceivably guzzle a lot of plain iced tea in one sitting, too. That's another low-sodium beverage. After a long day of working in your yard, losing sodium in your sweat all day, that pitcher of iced tea you gulped down could certainly lead to dilutional hyponatremia. Likely? Not really, but I think it's certainly conceivable IMO.

Certain folks, like exercise physiologists, have been saying this about Gatorade since sometime in the 80's. To me, Gatorade is a beverage first, a sport drink second. All the sugar and sodium are there primarily to enhance its flavor and sell more Gatorade, not to be the best sports drink. I also have problems drinking a large amount of Gatorade, and other ETS members have mentioned a similar experience over the years. I recall someone mentioning their Gatorade experience while deployed in Iraq and how they feel bloated. That happens to me, too.

If I'm drinking Gatorade for serious hydration purposes, I also dilute it by half with plain water. But ideally, I would drink something else. My personal favorite is Vitalyte.

Folks,

Some INPORTANT information, Yes, too much water without electrolytes (saltS) can be a problem, but a much larger problem is DEATH from too much sweating and too much Gatorade!! It has happened a number of times, and Gatorade is banned from some sports events.

Gatorade was designed at the University of Florida for football players in hot weather. It was NOT designed for hydration, but to solve electrolyte imbalance. It was administered by trainers, EMT's or physicians to those who showed the proper symptoms. WATER was given to those who were dehydrated!

Since the patents were sold, there has been a great push to use Gatorade for rehydration, but it has more salt than the human body. The first thing that happens is that it takes water OUT of the body to lower the salinity (osmosis). If you are already severely dehydrated this can cause the heart to stop.

Anyone who is eating normally (especially hikers munching on trail mix, nuts and jerkey and eating packaged foods) has little to worry about with water intoxication. They do need to consider the potential for problems if they get dehydrated and drink (uncut) Gatorade. If you like it, do the 50/50 mix or drink a similar bottle of water for every bottle of Gatorade. Stay hydrated and it is no problem. If you are showing signs of dehydration, drink water.

Respectfully,

Jerry

Just my $0.02, someone mentioned ERG. That has been renamed to Vitalyte. Vitalyte is amazing. I've used it when ill and during hot weather and I've found it to be one of the best ways to rehydrate without feeling bloated, etc...

Sean

This used to be a problem in the days of Ebeneezer Goode but became less of a problem when the Salmon Dance became more popular.

There is some good and bad information in this thread. As the EMS director for the Javalina Jundred and other ultra-marathons here in Arizona, the topic of proper hydration and nutrition are pretty important to me.

Typically the phrase "Water Intoxication" is used as a layman's term for hyponatremia due to excessive water intake.

Hyponatremia is a condition where there is an imbalance of water and sodium in the body with sodium levels being abnormally low. While there are many causes of this, it has become a topic of much discussion in the endurance sports community for a few years now. First coming to light in the 1982 Boston Marathon. Cynthia Lucero died in the last miles of the marathon, her death was linked to hyponatremia. Although reports vary, it seems she drank an excess of water and Gatorade during the marathon with little to nothing to eat. In the years since, multiple deaths and hospitalizations at endurance events, specifically events where athletes are participating for greater the 4 hours, have been linked to hypothermia and pour hydration/nutrition plans.

While it is possible to drink enough water while not exerting to drop your sodium levels to the point of danger, it would be somewhat difficult. Drinking that much water fast enough would make most people throw-up due to the significant change in stomach content osmolality. It is much easier to cause you sodium level's to drop due to sweating and exertion while drinking water or hypotonic electrolyte solutions and not replacing electrolytes.

No here is the big issue, most people cannot tolerate drinking isotonic (same concentration as the body) or hypertonic solutions during exertion. All "sports drinks" on the market are Hypotonic electrolyte solutions, including Gatorade. When exercising in environmental conditions where hyponatremia is a danger, electrolyte replacement is virtually impossible using water and sports drinks alone.

On the topic of Gatorade, it does not have a higher concentration of electrolytes then out body does. In fact a few years ago Gatorade came up with a new formula called Gatorade Endurance which had more electrolytes then the original specifically to address Hyponatremia. The problem with Gatorade and other similar drinks is the amount of sugar, in this sense it is hypertonic and can cause a loss of fluids and electrolytes (this is where the cutting Gatorade 50/50 advice comes from).

The key is finding a balance between hydration and nutrition. Most endurance sports participants who encounter electrolyte imbalances haven't taken on too much fluid, but rather have not eaten enough, taken any electrolyte supplements or tried to take in too much and now have GI issues causing the imbalance.

The solution to all of this is actually pretty simple:

First - Have a hydration and nutrition plan before hand.

If you are going to be doing an endurance event (be it a marathon, triathlon, or simply a hike) that is going to take more then four hours, work out a plan for nutrition and hydration before hand. To do this right you need to have practiced some before hand to know how much water, electrolytes and food you will need. One of the best ways to maintain you electrolyte levels is to eat consistently throughout the event. Make sure your food source has some electrolytes, one of the issues many athletes run into is relying of energy gels for their nutrition and not realizing most have little or no electrolytes. Many companies are making electrolyte supplements in pill and powder form now, these can be a godsend if used right (read the bottle) or a curse that will find you vomiting on the side of the trail is not.

Second - Know you limitations both physically and nutritionally.

You need to know how much you can do, and how much you can take in before getting into trouble. Training is the key.

Third - Know the warning signs.

Long before you get hyponatremic, there are signs that can tell you that you are heading down the path to trouble. The first warning sign will typically be swollen hands. Have you had to loosen your watch because you hands are swelling? It's time to slow down or rest and eat something. Other signs to look for are abnormal sweating, cramping, dizziness, weakness, insatiable thirst, swollen feet and ankles, "sloshy stomach feeling" and GI distress.

Last - Once you think you are in trouble, take you time.

It takes a while to drop your electrolyte levels, it will take a while to bring them back up. One of the biggest mistakes people make is trying to get the electrolytes in too fast. I remarkable number of athletes come into the aid station at Javalina Jundred complaining of vomiting and weakness. After asking some questions we typically discover the athlete started to cramp or swell and they started to take in a lot of electrolyte supplements. Soon there after, they stared to vomit. Most of these athletes we lay down and allow them to slowly eat and drink until they feel better. 30-45 minutes later, they are back out on the course and most finish the 100 mile race.

Soooo, a lot of interesting and technical information in this thread. I'm an intermediate (5-10 miles) distance walker, not a runner. I'm wondering; does it all boil down to a time tested solution? GORP and water as needed?

Replace your electrolytes.

Alan,

Thank you for the correction on Gatorade, my understanding of the cause of water loss is significantly improved.

The best,

Jerry

The best advice I ever got on food consumption when hiking was, "Lunch begins immediately after breakfast, and continues in small bits throughout the day."

One small question - Is it even possible to become dehydrated in the Land of 1000 Lakes? Seems like there is water everywhere. Maybe Florida has more, but it would be close.....