Exercise Associated Hyponatremic Encephalopathy, Gatorade and the ACSM

[Brian Chontosh]

Originally Posted by Andy Shirley

Gatorade is pretty isotonic. So is 5%dextrose in water, with absolutely no sodium at all. The relative amounts of sodium are what are relevant for cerebral edema(hyponatremic encephalopathy), which is why in my earlier post I said we consider Gatorade to be roughly equal to water in our patients on fluid and free water restrictions.

Hypertonic fluids are pretty foul, but not that bad. I've tasted 3% saline and 23% hypertonic saline(normal saline is 0.9%). Hypertonic solutions also cause terrible diarhea when consumed PO(by mouth) from the osmotic gradient, which is one reason why they are given IV.

Normal saline is slightly higher than serum sodium at 154meq/liter, compared to normal serum sodium of 135-145.

Andy, it is my understanding that Gatorade can have anywhere from 270-800mg Sodium per liter of solution (I suppose depending on the formula and generation of product). A standard .9% Saline IV has 9g of NaCl.

I'm not a scientist, mathematician, of doctor so if someone would like to just come in and trump me up I'm offering:

For .9% Saline
Molecular mass of Sodium = 23mg/mmol and Chloride is 35.4mg/mmol.
9000mg / 23mg/mmol = 391

For Gatorade (sodium considerations, I'm not interested in Glucose)
270mg (800mg) / 23mg/mmol = 11.7 (34.7)

It looks to me that Gatorade is 'hypo'tonic to a standard saline IV in regards to sodium. True? Isn't blood plasma ~134? If I am missing something, I apologize.

[Christopher Morris]

Andy and Brian,
What is the effect of a hypotonic P.O. fluid, then? The osmotic gradient would draw fluid from the digestive tract into the circulatory system of the body. From the circulatory system the fluids would either hydrate tissue or be excreted in the kidneys.

If the appropriate amount of sodium in the Gatorade is also getting absorbed, it would keep the sodium levels in the body constant. Normal sodium levels are 135-147 milliequivalents/L. If excessive fluid is being absorbed and diluting the sodium in the body, this would cause hyponatremia and its consequences. Severe hyponatremia is less than 120 mEq/L.

I'm just thinking this through.

Drinking too much Gatorade has caused hyponatremia. Drinking too much water would also cause hyponatremia. Would a moderate amount of Gatorade be beneficial over water? In the cases of hyponatremia deaths, were the victims drinking both Gatorade and water?

[Brian Chontosh]

Every time I try to wrap my head around the science it starts to hurt. My background doesn't fairly allow to dig into a cursory understanding of the biochemistry of AVP/ADH and such. I'll leave this for someone with the credentials to tackle it.

However, the reductionist in me wants to refocus the point: Overhydration is the issue. Let's not conflate tonicity, heat illness, or CHO consumption to increase performance.

Overhydration is killing.

Before the ACSM/GSSI changed the rules on hydration this disease (EAH & EAHE) didn't appear to exist. The first reported case was 1981. This disease was created when endurance athletes started consuming excessive fluids. It doesn't matter if the fluid is water or sports drink really. How and Why were recommendations changed so suddenly when there wasn't a problem? And, why have the recommendations only gradually and softly started to return to original dictates of thirst? I would have expected the opposite - a gradual changing of the rules at the onset and when deaths occurred an immediate, loud, and exhaustive correction.

[Christopher Morris]

Originally Posted by brian chontosh

Every time I try to wrap my head around the science it starts to hurt. My background doesn't fairly allow to dig into a cursory understanding of the biochemistry of AVP/ADH and such. I'll leave this for someone with the credentials to tackle it.

However, the reductionist in me wants to refocus the point: Overhydration is the issue. Let's not conflate tonicity, heat illness, or CHO consumption to increase performance.

Overhydration is killing.

Before the ACSM/GSSI changed the rules on hydration this disease (EAH & EAHE) didn't appear to exist. The first reported case was 1981. This disease was created when endurance athletes started consuming excessive fluids. It doesn't matter if the fluid is water or sports drink really. How and Why were recommendations changed so suddenly when there wasn't a problem? And, why have the recommendations only gradually and softly started to return to original dictates of thirst? I would have expected the opposite - a gradual changing of the rules at the onset and when deaths occurred an immediate, loud, and exhaustive correction.

This answered my question.

I'm still working on reading the articles Russell linked. I'm interested in going back to the ACSM/GSSI studies on heat exhaustion, etc. to see why they recommended excessive drinking in the first place.

[Andy Shirley]

Normal serum sodium is 135-145 meq/liter. And I completely agree that Gatorade has much less sodium than blood or normal saline, essentially zero. Anyone who acutely drops their serum sodium will have brain swelling to some degree. At a certain point this becomes too much edema and you die.

I'm not interested in glucose either. But it contributes to tonicity.

Originally Posted by brian chontosh

Andy, it is my understanding that Gatorade can have anywhere from 270-800mg Sodium per liter of solution (I suppose depending on the formula and generation of product). A standard .9% Saline IV has 9g of NaCl.

I'm not a scientist, mathematician, of doctor so if someone would like to just come in and trump me up I'm offering:

For .9% Saline
Molecular mass of Sodium = 23mg/mmol and Chloride is 35.4mg/mmol.
9000mg / 23mg/mmol = 391

For Gatorade (sodium considerations, I'm not interested in Glucose)
270mg (800mg) / 23mg/mmol = 11.7 (34.7)

It looks to me that Gatorade is 'hypo'tonic to a standard saline IV in regards to sodium. True? Isn't blood plasma ~134? If I am missing something, I apologize.

[Andy Shirley]

Again I agree that over hydration kills, and the water and Gatorade are roughly equivalent as far as the effect on serum sodium.

It is fairly simple in how we manage serum sodium in the ICU. If we want the sodium higher to bring down cerebral edema, we give salt(IV)to drive it up(some time up to 160-170 in extreme cases). If the sodium is too high and there is no longer cerebral edema, we bring the sodium down gently, with oral water, or with IV water(with dextrose, or lower than normal saline--half normal or quarter normal)

Originally Posted by brian chontosh

Every time I try to wrap my head around the science it starts to hurt. My background doesn't fairly allow to dig into a cursory understanding of the biochemistry of AVP/ADH and such. I'll leave this for someone with the credentials to tackle it.

However, the reductionist in me wants to refocus the point: Overhydration is the issue. Let's not conflate tonicity, heat illness, or CHO consumption to increase performance.

Overhydration is killing.

Before the ACSM/GSSI changed the rules on hydration this disease (EAH & EAHE) didn't appear to exist. The first reported case was 1981. This disease was created when endurance athletes started consuming excessive fluids. It doesn't matter if the fluid is water or sports drink really. How and Why were recommendations changed so suddenly when there wasn't a problem? And, why have the recommendations only gradually and softly started to return to original dictates of thirst? I would have expected the opposite - a gradual changing of the rules at the onset and when deaths occurred an immediate, loud, and exhaustive correction.

[Brian Chontosh]

Originally Posted by Andy Shirley

Normal serum sodium is 135-145 meq/liter. And I completely agree that Gatorade has much less sodium than blood or normal saline, essentially zero.

9000mg / [23mg/mmol Na + 35.4mg/mmol Cl] = 154 ((.9% Saline IV))

Blood Serum Sodium 135-145meq/L has ~3100-3300 mg/L of Sodium. Divide out the molecular weight of 23mg/mmol and you get 135-143 meq/L.

So we are talking the same circular language. But, Exercise Associated Hypo(Na)tremia = I really care about the Sodium.

Gatorade 845mg Na / 23mg/mmol = 37.

If administering a .9% Saline IV (isotonic sodium solution) to an athlete suffering EAH continues to threaten livelihood through overhydration and further reducing sodium levels (in the presence of SIADH), drinking a Gatorade (hypotonic sodium solution) seems to do so at a factor of x10.

I'm not interested in glucose either. But it contributes to tonicity.

Introducing tonicity again is why so many people get confused. Yes, Dextrose contributes to tonicity (Glucose in the case of Gatorade). In a D5NS (5% Dextrose Normal Saline) IV it increases tonicity to assist in hydration. While in Sports Drinks it is also for purported energy and most significantly for taste.

If someone is already hydrated, overhydrated even, why do I care about hydration? And when the low sodium levels are what I am most concerned with why would I want to hydrate more with a product that contains significantly less sodium in solute to hydrate with?

I don't care about Tonicity. I care about Sodium regulation. Again, we get off track… Why are we over drinking? Who told Cynthia that she needed to drink 1.2 L/hour to stay safe?

[Russell Greene]

Originally Posted by brian chontosh

I don't care about Tonicity. I care about Sodium regulation. Again, we get off track… Why are we over drinking? Who told Cynthia that she needed to drink 1.2 L/hour to stay safe?

Tosh,

I fear you may be letting Gatorade/ACSM get off easy. The 1.2 L/hour was a bare minimum for Gatorade:

"as recently as January/February 2002 (ie, 11 years after EAH was proved to be due to overdrinking), the GSSI placed an advertisement in the New York Runner magazine, and presumably elsewhere, with the banner statement: 'Research shows your body needs at least 40 oz. of fluid every hour (ie, 1200 ml per hour) or your performance could suffer'. This conclusion is allegedly based on the results of 'thousands of tests' conducted by the 'scientists of the Gatorade Sports Science Institute' who have 'studied it for over 15 years in research facilities all across the country'."

source (w/f safe): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2658915/

In short, Gatorade did not stop at funding the ACSM's bad hydration science - they distorted and misrepresented the ACSM's bad science. The New York Runner ad also ran in the North West Runner magazine, and presumably elsewhere: http://faculty.washington.edu/crowth...confuse2.shtml (w/f safe)

Contrary to Gatorade's distortion, the 1996 ACSM recommendations used 1.2 L/hour as a maximum, not a minimum value, with the caveat that a runner should only drink as much as he could tolerate. The 1996 recommendations were excessive, and the 2007 ACSM recommendations implicitly recognize that. Yet Gatorade was still not satisfied with how much hydration the 1996 guidelines recommended.

If the ACSM objected to their platinum sponsor's misrepresentation of their guidelines, I've found no record of it. An ethical scientific body would have spoken up.

The need to remove Gatorade's pernicious influence from exercise science could not be clearer.

[Rob McBee]

Originally Posted by Lynne Pitts

To "sweeten the pot" CrossFit has 500 copies of Noakes' book available to give to interested parties; reply in this thread if you would like one. We'll grab your email from the admin side, so you don't need to post your email publicly, and our team will contact you for the rest of your information.
Requests so far - will keep this updated, so hit me if I miss you.

Joshua J Grenell
Chris Cooper
Christopher Morris
Dakota Base
Andy Shirley
Russel K Olofson
Teena Escobar
Amy Hollingsworth
Jason Donaldson
Alden Hingle
Christopher E Bloom
Jesse Phillips
Barry Stockbrugger
Ryan Kingsbury
Darrel White
Kirez Reynolds
Darby Darrow
MIchael Wuest
Jason David
Kevin Keast
Joey Dussel
Adam Manery
Robert D Taylor Jr
Mark Lamoree
Greg Whitekettle

Hi Lynne! I would be very interested in reading "Waterlogged" if copies remain. Will buy my own if not due to the interesting discussion. Seeing you, Coach, Dale, Russ all posting in one thread! Feels like 2005-7. Thank you and take care all.

Rob

on the list - Lynne

[Dustin Wintczak]

What exactly just happend over the past 11 pages?

"...what you've just said is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul."

I think that sums up this entire discussion.

But really, are we moralizing about the marketing of sugar water because a statistically insignificant amount people don't understand the idea of moderation? Really? This is a battle you'd like to fight?

The cognitive dissonance on display in the arguments for driving "big soda" out of the fitness industry is, frankly...well not surprising.

So "big soda" = bad, then alcohol would have no place in fitness right? Even if it was marketed in a way that would appeal to a younger fitter demographic. CF would never take money and allow a compan...

Oh right...

http://games2011.crossfit.com/conten...d-vendors.html

But that was just vendor, just there to sell product to all the fans. They wouldn't, oh I don't know allow a corporate sponsor who markets fat, salt and sugar laden food to spon....

http://games2009.crossfit.com/sponsors/

Ohhhh! Man...really? Ok, ok...well we know after reading all these studies from as far back as 1996 according to one of the Russell's, that Gatorade is bad right? So we've known about this and would NEVER allow them to spons...

http://games2008.crossfit.com/

godamnitsomuch

So I'm a bit confused now, is this just moral relativism or did HQ give back the money paid to them by Gatorade, Panda Express and Michelob Ultra?

I'm sure you're aware all links are wfs

"Smokey, you're cool.....I'm outta here."