Hydration and Hyponatremia - why electrolytes are a good thing

Triathlon Forum
1

So recently there were a couple of threads about whether to take electrolytes with some strident arguments against…

I am one of the physicians in the tents at the finish of the Boston Marathon, and in getting ready for monday we received a few documents. I thought I would share a bit from the one entitled ‘scale program’ - weights before and after the run really help us as physicians determine what is going on.

Many published articles on hydration suggest that fluid prescription is very much an individual determination. A multitude of factors will affect the sweat rate of any athlete. Heat, humidity, environmental factors, and overall conditioning play important roles in determine the rate of fluid loss.

Unfortunately, marathons and long distance events have witnessed increasing numbers of runners who present with signs and symptoms of hyponatremia. This is a **condition that reduces the body’s sodium levels and in most cases elevates total body water. **

The profile of individuals prone to Hyponatremia usually falls under the following categories: Slow Runner > 4 hours to complete the eventSmall statureFemale genderHistory of over hydration pre and during the eventHistory of using NSAID (motrin, advil, aleve etc) on the day of the event.

Symptoms include: (Note: Many of these symptoms mirror symptoms of dehydration) Mental confusion/head acheLight headedness/dizzinessNauseaVomitingSalt caked on skin ~ hot daysNormal vital signsDemonstrable weight gain/look for swollen hands & feetSevere FatigueWheezingSeizureComa

Runners and medical staff should keep in mind that a pint of fluid is equal to 1lb. Fluid replacement (preferably with a sport drink), should be equal to the amounts of fluids lost during exercise. Runners complaining of the above symptoms, and have indicated a solid history of fluid intake (pre & post event) are NOT always dehydrated. In addition to inquiring about weight gain during the race, if the runner utilized the available scales on the race course.

Before providing any fluid (orally) a comparison of weight gain or loss should be determined by using the scale. Runners feeling ill with associated weight gain, and that have characteristics of the above categories are candidates for the condition of hyponatremia. Under no circumstances should any fluids, including a sports drink, be given to the runner. Both water and sports drink may cause this condition to worsen cause irreversible brain damage, and death.

So, if you are not hydrating with a sports drink during endurance events, taking electrolytes (including sodium) along with your water are a good idea!!!

cheers

2

I have had a kidney transplant and I am very leary of taking high amount of sodium. How do I know if I am deficient in sodium during excercise and how do I know the rate at which I am being depleted? Should I use my sweat rate? What sthe best way to calculate sweat rate?

3

But but but…daremo says I don’t need any electrolytes:

Bottom line is though, there is little to no proof that you need to replace electrolytes DURING exercise.

Am I supposed to believe you or him, because he did say he heard about this in a coaching seminar which means it must be true!
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4

So, if you are not hydrating with a sports drink during endurance events, taking electrolytes (including sodium) along with your water are a good idea!!!

This is a good reminder to some folks, but a better reminder would be to tell them to know how much water they ought to drink and limit their intake to the correct amount. I have read way to may thread on this forum about how to pee while riding and on every one I comment that peeing on the bike means you are drinking way too much. Many of them seem to think you can’t take in too much water, but this is obviously not true.

Chad

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I recently heard an interview with Joe Friel and it sounds like he’s reconsidered the generally accepted recommendations to hydration. In the interview, Joe states that in endurance events, the winner of the race is often times the most dehydrated athlete in the field. He contends that the effects of (mild) dehydration on performance are not nearly what we’ve been told and that the bigger concern should be over hydration.

As someone whom has finished several events suffering various degrees of hyponatremia, I’m really interested in the subject. Prior to hearing this interview, I’d been experimenting with supplementing with LOTS of sodium >1200mg/hr during 1/2IM to IM, to combat this, but now I’m considering that I may just need to cut back on the fluids.

EDIT:

Found a couple of links to Joe’s blog where he writes about this:

http://www2.trainingbible.com/...exercise-part-1.html

http://www2.trainingbible.com/...exercise-part-2.html

http://www.trainingbible.com/joesblog/2008_09_01_archive.html (part 3)

http://www.trainingbible.com/joesblog/2008_10_01_archive.html (part 4 - bottom of page)

6

I remember reading in a sports medicine book over 20 years ago (so may have been suspect?) that electrolyte loss can be diminished to nearly nothing through acclimation. The idea is that if you have a diet that is restricted in electrolyte intake (or at least sodium) then your body will learn not to excrete it in sweat thereby protecting you from electrolyte depletion during excercise.
It actually recommended a low-sodium diet for runners.

If this were true, and an athlete were properly trained for this, then wouldn’t hyponeutremia be very unlikely since electrolytes aren’t being depleted in the first place?

Are we doing ourselves a disservice by paying such close attention to electrolyte replenishment and supplementation on a continual basis?

7

I would talk to your nephrologist as a transplant has with it other issues - you are (I assume) on immunosuppresants and that effects all of your physiology. So for you not such a simple answer. Frankly if you showed up in the med tents I am SURE we would transport you to the hospital for monitoring…

sorry I am not more help but I was trying to address the general case, not the exceptions.

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snort
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Chad I totally agree - the first paragraph states that it is individual!!!

and yeah, I have yet to need to pee on the bike -

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funny, he and I have been twittering regarding this issue
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that sounds off - we are not organisms that adjust our sodium concentration by environment…we need to stay within a certain pH…

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that sounds off - we are not organisms that adjust our sodium concentration by environment…we need to stay within a certain pH…

Yes, and to regulate that sodium concentration appropriately, is it possible that our bodies will learn not to waste it through secretion in sweat? I’m not making a claim, just asking you about something I’d read decades ago…thanks.

13

I agree with you.

I have lost up to 5 kg (from my 75 normal weight) in one training, and felt perfectly fine. I ate some salty food, and drank some extra water in the evening. No problem. But if I would have tried to drink that 5 litres of water during excersise and without that salty food I was in the danger zone for low natrium contents in the body. If an athlete goes for 10-15 hours of racing in heat you simply can’t drink what you transpire without problems. Only solution is to accept the dehydration.

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So, if you are not hydrating with a sports drink during endurance events, taking electrolytes (including sodium) along with your water are a good idea!!!

Do you have any evidence that supports this conclusion?

15

But but but…daremo says I don’t need any electrolytes:

Bottom line is though, there is little to no proof that you need to replace electrolytes DURING exercise.

Am I supposed to believe you or him, because he did say he heard about this in a coaching seminar which means it must be true!
Did a sprint Du on Saturday. Short race with a 5K run & 11.2 mile bike, weather was fairly cool in the mid to upper 60’s, took me a bit under 51 minutes. Finished the race with VERY visible salt rings about 4" up from the bottom of both legs on my shorts. You can’t imagine the salt fields I had caked on me after the NO70.3.

So all the experts & pseudo experts can blow all the smoke they want, but for this N=1 experiment in athletics, replacement is a necessity in longer events. I’ve got 25 years of experimentation under my belt that tells me that. These guys remind me of the creationists. (Damn that mountain of evidence, that’s not proof to me, I can explain it all away).

JJ

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So, if you are not hydrating with a sports drink during endurance events, taking electrolytes (including sodium) along with your water are a good idea!!!

Do you have any evidence that supports this conclusion?

yeah the almost 300 people I treated after the marathon today
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that sounds off - we are not organisms that adjust our sodium concentration by environment…we need to stay within a certain pH…

Yes, and to regulate that sodium concentration appropriately, is it possible that our bodies will learn not to waste it through secretion in sweat? I’m not making a claim, just asking you about something I’d read decades ago…thanks.
Evolution does not work that fast

18

This is something pretty close to me and something that a lot of people seem to get wrong.

This is real people and once it happens you can be dead or irreversibly damaged very quickly.

The sister of one of my friends ran the Rome marathon. She doesn’t like sports drinks so only drank water. On crossing the line she displayed this symptoms listed and collapsed. Her life was saved because she was speaking with a doctor at the time, had communicated that she’d only been drinking water and the doctor treated her very promptly. She came out of a coma a week later and doesn’t suffer many serious effects other than memory loss.

All this talk about exercising without electrolytes is fine, just make sure you don’t drink too much water. Of course you need to take into account your sweat rate and latent sodium levels when calculating how much water you can drink safely. How accurately can you do this whilst exercising? Why take this risk?

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Just to clarify…I wasn’t speaking of evolution, but rather wondering if there is an existent adaptive mechanism.

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I know, but that is why I answered that way - no we do not adapt that fast. The kenyans will say that they purposely run for hours/days without water to get used to it but there may be subtle differences in their transport mechanisms.