Interesting article on overhydration and endurance sports.
http://news.yahoo.com/s/livescience/enduranceathletesriskdeadlywaterintoxication
overhydration or too little sodium you make the call 
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andy, you reading this? the evil wing of the ex-fizzers and armchair quarterback doctors are winning the battle for hearts and minds. but, at least they’re doing their part to stop all those hyponatremia deaths that occur annually, like clockwork, during marathon and ironman season 
overhydration or too little sodium you make the call
It’s overhydration. Go to medline, look for some of the recent work on the subject (noakes, speedy, etc) and follow the paper trail.
Some trainers and sports physiologists contend that by the time you’re actually thirsty, you have lost enough fluid to already be dehydrated, so they say you need to drink in anticipation of becoming dehydrated, Verbalis explained. “We dispute that notion," he said, "and contend that thirst is a good indicator of your body’s need for fluids, and that there is a window of time over which you can rehydrate safely.”
the evil wing of the ex-fizzers and armchair quarterback doctors are winning the battle for hearts and minds. but, at least they’re doing their part to stop all those hyponatremia deaths that occur annually, like clockwork, during marathon and ironman season
Huh?
overhydration or too little sodium you make the call
It’s overhydration. Go to medline, look for some of the recent work on the subject (noakes, speedy, etc) and follow the paper trail.
If I’m remember right, both those studies where done with fluid loading at rest, not exactly a real world test.
There are fairly consistent observational studies from IM and marathon events demonstrating that weight LOSS is associated with no hyponatremia and faster finishing times.
As I said, read the papers and follow the paper trail. For instance:
Br J Sports Med. 2006 Mar;40(3):255-9.
There are others which are also “real world”.
“Huh?”
with respect, a lot of folks in science would say it is you who needs to, “follow the paper trail.” yes, noakes has written reams about this. he’s also been the most successful evangelist in this area, which is pretty remarkable when one considers that the big money is with the manufacturers (e.g., gatorade) who’re more consistently standing on the other side. my point is, for all the noakesians there are at least as many, most probably more, anti-noakesians. we just had a thread about this within the past week.
i don’t have a dog in this. i’ll go where the science leads. i’m interested in seeing how you characterize the anti-noakesians. or would it be anti-noakesists?
Dan,
Sounds like time for another ST investigation topic. You did a wonderful job on Global Warming, wonder what you could dig up on this one?
Well,
on the flip side: What about the aspect of conditioning your body to retain fluids more efficiently?
Fact is: Some people tolerate dehydration much better than others… and get more easily “overhydrated”.
So, it certainly makes sense to look into that.
Training while constantly slightly dehydrated could actually improve the bodies resistance to dehydration?
Blasphemy!
“Drink responsibly”
“Sounds like time for another ST investigation topic.”
i thought the very same thing. hence my post on pz pearce (whom i do not know). as it happens i’ve formed friendships with some of the folks who’re front and center on this issue. it’s remarkable to me that something this basic an elementary is in such play: am i supposed to drink before i’m thirsty? after i’m thirsty? is that really thirsty, or just kinda thirsty? and should i take 20 salt tablets during my IM, or no electrolytes at all, or something in the middle?
Well, I think there are a couple of things that bear mentioning…
Noakes is an evangelist, to be sure, and I think he often overstates his case and perhaps evangelizes to the detriment of his cause. I do not necessarily see a great conspiracy of manufacturers to misinform. Nor do I think the ACSM made up it’s hydration guidelines (which are changing to be more “Noakesist”, as I understand it) based on influence from the supplement industry. All that said…
I disagree with your assertion that there are as many “Non-Noakesians” at this point as there are “Noakesians”. Even in the purely clinical setting (which usually lags the research world by a fair measure), there were nephrologists saying the same sorts of things before Noakes really got any steam behind him. At the end of the day, exercise induced hyponatremia fulfills the major diagnostic criteria of SIADH, the primary treatment of which is water restriction. Is it possible to have hyponatremia in the settings of euvolemia, hypovolemia, and hypervolemia, yes. However, the euvolemic and hypovolemic varieties are not typically seen in the endurance sports arena. Some of us were talking this over at the latest ACSM meeting…none of us could recall a case of hyponatremia in an endurance athlete that was anything other than hypervolemic.
I can’t say too much about the “Non-Noakesians” at this point, simply because their viewpoint is not well represented in the literature. I can say that most of the sports physicians I have worked with who were “Non-Noakesians” were of that ilk because they were unaware of recent publications, and because they live and die by documents such as the ACSM’s guidelines, rather than the primary literature.
Is it as simple as voluntary “overdrinking”? Maybe, maybe not, at least not in all cases. People with SIADH are driven to drink, and I do not think such a phenomena is outside the realm of possibility in endurance athletes. However, as far as I know no one has demonstrated such a drive in endurance athletes, or formally investigated the motivation of the athletes to drink quite so much. I suspect it might go beyond that they got poor hydration advice (“drink as much as you can”.) I can say that in the cases where I have played a major role in treatment (around a dozen, all told, some worse than others), I have only heard variations of one explanation. “I was feeling bad, and I thought I must be dehydrated, so I drank more.” All patients had had a significant weight gain, which can mean only one thing: a positive fluid balance.
Are there other viewpoints, sure. However, the people who believe hyponatremia is due to electrolyte loss don’t have much data to stand on. The people who believe it can be corrected through the administration of oral electrolyte preparations are lacking data as well.
At this point, I think it is pretty hard to argue with the overdrinking argument. I think there is more to be learned about the actual mechanism, but at the end of the day, the treatment may well be the same.
Phil
“I can’t say too much about the “Non-Noakesians” at this point, simply because their viewpoint is not well represented in the literature.”
that’s interesting. i wonder whether andy coggan, or bob murray, would agree with this statement. and, it guess it depends on what among noakes’ views you consider officially noakesian, his views on over-hydration, or what i take to be his views on whether and how much electrolyte replacement matters during an endurance event?
I’m not sure what the definition of Noakesian is, but athletes don’t get hyponatremic if they don’t gain weight - this is a robust finding from multiple studies. Weight gain is from overhydration, independent of salt intake. A long distance athlete who maintained a perfect volume status would actually lose weight, through aerobic metabolism of carbs/fat. The common denominator in hyponatremia is weight gain. You don’t gain weight by losing salt. You gain weight by drinking.
Based on personal experience, I agree with this. I’m the only one in my 45-minute spin class without a water bottle. Don’t need one. When I did my first two marathons and first triathlon, I followed the conventional wisdom and drank a lot and was sick as a dog. When I do sprint tris now, I get by with a sip of water in T1 and T2. Anything more and I get nauseous. My daughter is the same way. Must of had some camel beastiality going on with my ancestors.
BTW, when I see people walking around downtown Chicago with their water bottles it reminds me of babies with their pacifiers.
hat’s interesting. i wonder whether andy coggan, or bob murray, would agree with this statement. and, it guess it depends on what among noakes’ views you consider officially noakesian, his views on over-hydration, or what i take to be his views on whether and how much electrolyte replacement matters during an endurance event?
Can’t say Andy and I have ever discussed hyponatremia / electrolytes. In any case, you need only go to Pubmed and start poking around. It has been several months since I have done a really thorough literature search on the subject, but as of my last major library dive, there wasn’t much out there on the electrolyte-supplementation-as-prophylaxis issue…and what was out there leaned more towards the “not mattering” end of things. There are sports docs out there who have their football players drinking pickle juice and whatnot, but the real question is how much of what passes between the lips ends up in the plasma, and even if it does, does it matter? That has been a hard case to make, so far.
There was a study (again, by noakes et al, IIRC) where they showed that the link between electrolyte imbalances and cramping was somewhat weak. Now, I have anecdotal reports from my patients who claim their cramping issues magically disapeared after taking endurolytes or something…and really, who am I to argue with them? It worked for them, they are happy, fantastic. But in the bigger picture, we need to be more evidence based than that. At least, I feel like I need to be.
Regarding the hypervolemia thing, I can’t find much to criticize there. That work is quite well replicated…gaining weight = lower sodium. If you have a line on some good data that says otherwise, I’d be interested in it.
Phil
When I do sprint tris now, I get by with a sip of water in T1 and T2. Anything more and I get nauseous. My daughter is the same way. Must of had some camel beastiality going on with my ancestors.
BTW, when I see people walking around downtown Chicago with their water bottles it reminds me of babies with their pacifiers.
By best half-IM effort was on about 40-50 oz of water and the last one at World’s Toughest Half was about 70 oz for not quite five hours of effort. I always get attacked when I see threads about peeing on the bike and suggest that if they are doing that then they are drinking too much. People ought to experiment with how much they should drink and then get by with the bare minimum for racing. More is not better in this case, but heaven help you if you try and convince anyone of it.
Chad
“There was a study (again, by noakes et al, IIRC) where they showed that the link between electrolyte imbalances and cramping was somewhat weak.”
i see to recall from noakes the view that it matters not whether you take electrolyte replacement or clear water, there’s not demonstrable benefit to either over the other. if i am representing this correctly as his view, i personally think that’s the more eyebrow raising believe than the hypervolemia views he holds.
that said, i’m going to have to be brought along to the view that dehydration is not really anything to much worry about, whereas hyponatremia is the big flashing red danger light. i find this a bit ironic since in 2001 noakes was considering not allowing petr vabrousek to compete in IM south africa (noakes was the race’s medical director) because the czech was admitted to the hospital a week before, diagnosed with heatstroke and gastroenteritis. heatstroke is specifically hypovolemic. noakes would tell you that elevated rectal temps are very rarely seen in these long distance athletes. i suspect when noakes shoved a thermometer up petr’s ass it registered pretty red.