The Dangers of Over-Hydration: 5 Tips to Prevent It

Over-hydration (“hyponatremia”, also sometimes called “water intoxication” or “water poisoning”) is not something you hear or read about very often. However, it can be just as fatal as dehydration.

Usually, what we read about during the hot summer months is heat stroke. This can lead to the assumption the way to combat both is drink more water. What can happen instead, is the person drinks an excess of water.

Runners, hikers, football players—even someone working in their garden on a hot summer day—can make this mistake.

And sometimes, well-meaning, but under-informed, coaches can as well.

For example, over a 15-year period between 1983 and 1998, an excess of 700 cases of exercise-induced hyponatremia were documented during the Kona Ironman Triathalon. The participants had been encouraged to drink copiously, the belief being they would “bank” the excess fluids and draw from them over the course of the event.

(It’s also happened to rave goers; knowing the environment, the dancing and the preferred drug of choice—Ecstasy—will lead to dehydration, ravers have consumed 1-2 gallons in a single sitting shortly before the event.)

But how is an excess of water bad for you?

How could it be that too much of what we rely on, even more so than food to a certain extent, could be bad for us?

Think of a sponge—it absorbs a certain amount of liquid until it hits its saturation point. After that, no more liquid can be “processed” by the sponge.

The same thing happens to your kidneys—they can only process a certain amount of water over a specific amount of time.

In an effort to expel the over-saturation of water, your body eliminates it through your bladder.

While this is a normal enough action, if it’s because you’re over-hydrated, your body is unable to absorb the nutrients carried by your blood are now exiting your body.

In short, you drown from the inside out.

But here’s what’s confusing—your body, now sick with too much water, reacts in the same way it does to severe dehydration and heatstroke:

1. Confusion and lack of focus

2. Nausea/vomiting, diarrhea

3. Headache due to brain swelling

4. Excessive thirst

5. Irritability

Believing more water is needed, the athlete consumes more. Just as with dehydration, the body begins to shut down. Left untreated, it leads to cramps, seizures, coma and even death.

(In a way, your body becomes dehydrated due to the massive overdose of water it cannot absorb and process correctly.)

It’s an easy mistake to think drinking a lot of water before an event, and during it, is the best and healthiest way to prevent dehydration. The damage, however, is the same.

Who is most at risk for over-hydration?

1) Endurance athletes such as hikers, cyclists and runners who are participating in their sport for four or more hours, especially in hot sunshine.

2) Athletes participating in team sports like football or baseball. It can also occur in hockey; while the environment is colder, the combination of a high physical output and the heavy kits induce sweating similar to athletes in warmer environments.

3) Children under one-year-old because of their low body mass.

4) Those who are not used to the heat of the environment. If this is the case, it’s easy to think as above—more water is better to help the body maintain hydration.

5) Women. Women statistically experience higher rates of water intoxication and hyponatremia. It’s not known why, but it’s thought it’s due to women having a smaller body mass and possibly higher rates of fluid loss (resulting in an attempt to prevent it) during their period.

So how do you prevent over-hydration?

By following the tips we give below, you’ll ensure you remain properly hydrated, and not swing towards either over-hydration or becoming dehydrated.

1. Sip the Water, Don’t Chug It

The point is to maintain hydration throughout the day and your workout session. “Yo-yo” hydration makes it hard for your body to process the fluids and keep you hydrated.

Keep a water bottle or hydration bladder at hand and take frequent sips over the course of an hour or day.

2. Know Your Sweat Rate

Weigh yourself prior to a training session. Work out as usual, then weigh yourself, taking into account any fluids you drank during the session.

For every 1 pound lost during the training session, replenish with 16 oz water.

You can also drink water in batches, weighing yourself each time, until your weight has reached what it was prior to your workout. Note how much water it took, and use that as a guideline.

If you gained weight, you over-hydrated.

3. Maintain Your Carbohydrates and Electrolytes (Especially Sodium)

One way to do this is to use Gatorade; cut it 50/50 with water and drink 64 ounces over the course of 4-6 hours. You can also add a little salt (1/8th teaspoon per 8-12 oz) to your water, as well as lemon or lime juice.

A hotter environment will require a higher level of attention (still within reason and mindfulness to not over-hydrate).

An air conditioned office and/or home will, too. Air conditioning dehumidifies your home, causing you to lose fluids at a higher rate through your skil.

If you don’t have access to Gatorade, or you don’t want to consume it, consider the way firefighters maintain proper hydration.

From a wildland firefighter: “In wildland fire we do a little bit more than 8 ounces—we do 16 per hour for good hydration, plus most of us are chewing seeds or something for electrolyte replacement.”

4. Get to Know Your Pee

Lemonade yellow/green is good (if you take B vitamins, it may be a brighter shade.)

Dark (and/or thicker) lime green/lemon yellow urine can indicate early signs of dehydration, if not actual.

If you see brown, that’s a sign of severe dehydration (the color is from muscle tissue exiting your body).

Clear could be a sign you’re overdoing it and need to cut back on the water intake.

5. Pay Attention to Your Caffeine and Alcohol Intake—Especially on Days You Work Out

Both alcohol and caffeine act as diuretics when consumed, causing you to urinate at a faster rate. It’s easy to fall into the same line of thinking mentioned earlier—that by drinking a higher level of water, you’ll prevent dehydration.

But because your kidneys are working to process the alcohol and/or caffeine, they won’t be able to correctly process a high(er) level of water intake.

The trick is to maintain hydration, rather than trying to prevent it ahead of time.

If you remain properly hydrated, that will prevent both over-hydration and dehydration.

Train hard and train SMART!


QUESTION: Hi Coach Brad. I started CrossFit a couple months ago and love it but I’m hungry all the time. How can I make sure I’m eating right? How do they do it in the SEALs when you’re training?

ANSWER: Here’s an article I think you’ll find helpful: Navy SEAL Nutrition Tips.

QUESTION: I am really struggling to do a full, single pull-up. I’ve been doing negatives and using a band and I can tell I’m getting stronger, but I just cannot seem to execute a full pull-up. Help!

ANSWER: Check out this article: Pull-Ups—A Brief Guide to Getting Your Chin Over The Bar. I wrote it for another athlete who was having the same problem.



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