Overhydration and Endurance Running(irunfar.com)
irunfar.com
Overhydration and Endurance Running
http://www.irunfar.com/2012/07/waterlogged-a-dogma-shattering-book.html
6 comments
Dark urine is a sign of a lot of things, but also dehydration.
Frequent urination is a sign of a lot of things, and also over-hydration.
However, assuming either are related to your present hydration is dumb.
If you're regularly saying "my urine's dark, I must be dehydrated" you should probably be visiting a doctor.
Frequent urination is a sign of a lot of things, and also over-hydration.
However, assuming either are related to your present hydration is dumb.
If you're regularly saying "my urine's dark, I must be dehydrated" you should probably be visiting a doctor.
> If you're regularly saying "my urine's dark, I must be dehydrated" you should probably be visiting a doctor.
um, well, maybe, but it is accurate (and interestingly, a bit more Bayesian) to say "Hmmm... my urine appears to be darker than it was previously. Without evidence supporting a competing hypothesis, this is most likely because I'm relatively closer to the lower end of normal total body volume". Competing hypotheses include rhabdomyolysis, acute renal injury, chronic renal injury, and all the many things that cause those sorts of end organ damage.
I know HN has at least on board-certified nephrologist lurking around. perhaps he'll chime in.
source: I'm a physician.
Also, I think Noekes raises some very interesting points. I'm a little concerned by the tone of this article, though overall I'm glad the author made the effort to write it. Things like saying Noekes only found 6 instances of heat exhaustion found in the setting of long-distance running are suspect. Doing a lit review is suspect, and in a case like heat exhaustion, it's very tricky to demonstrate the literature reflects the population. Do you really think every patient with heat exhaustion after a marathon got a case report written up? I don't.
um, well, maybe, but it is accurate (and interestingly, a bit more Bayesian) to say "Hmmm... my urine appears to be darker than it was previously. Without evidence supporting a competing hypothesis, this is most likely because I'm relatively closer to the lower end of normal total body volume". Competing hypotheses include rhabdomyolysis, acute renal injury, chronic renal injury, and all the many things that cause those sorts of end organ damage.
I know HN has at least on board-certified nephrologist lurking around. perhaps he'll chime in.
source: I'm a physician.
Also, I think Noekes raises some very interesting points. I'm a little concerned by the tone of this article, though overall I'm glad the author made the effort to write it. Things like saying Noekes only found 6 instances of heat exhaustion found in the setting of long-distance running are suspect. Doing a lit review is suspect, and in a case like heat exhaustion, it's very tricky to demonstrate the literature reflects the population. Do you really think every patient with heat exhaustion after a marathon got a case report written up? I don't.
The fact that there will be a potentially huge percentage of heatstroke cases going unreported doesn't destroy the claim that a body temperature of over 45 degrees is rare, though it may weaken it.
I don't really think every patient with heat exhaustion after a marathon got a case report written up, but I don't care.
I don't really think every patient with heat exhaustion after a marathon got a case report written up, but I don't care.
As a cyclist from Arizona I stopped reading after seeing that. Complete BS. Lying via omission to support your claim is not a great way to inspire trust.
I can't tell if you are agreeing with me or arguing against me because you didn't get the point of/read all of my comment. In case it's the latter:
>However, assuming either are related to your present hydration is dumb.
That's exactly why I said "a symptom alone never makes a diagnosis" and "you can't assume you are dehydrated/your kidneys aren't working right based on those signs by themselves".
>However, assuming either are related to your present hydration is dumb.
That's exactly why I said "a symptom alone never makes a diagnosis" and "you can't assume you are dehydrated/your kidneys aren't working right based on those signs by themselves".
Tim Noakes has been talking about the over-hydration problem for a while.
It isn't clear to me how big a problem it really is. His recommendation of 400-800ml per hour for all endurance athletes isn't exactly controversial. In cycling lore the advice is 1 bidon/hour, which is around 600ml.
It's true that his advice against sodium supplementation doesn't suit sports drinks companies, but I don't think this is controversial from a sports-science point of view either. Sodium/electrolyte replacement drinks are unlikely to be harmful, and there is some evidence that some people find them easier to drink when exercising hard.
It isn't clear to me how big a problem it really is. His recommendation of 400-800ml per hour for all endurance athletes isn't exactly controversial. In cycling lore the advice is 1 bidon/hour, which is around 600ml.
It's true that his advice against sodium supplementation doesn't suit sports drinks companies, but I don't think this is controversial from a sports-science point of view either. Sodium/electrolyte replacement drinks are unlikely to be harmful, and there is some evidence that some people find them easier to drink when exercising hard.
I have a buddy who is an MD for various ultramarthons, and I've helped him with a few local 'nonultra' marathons (I'm a paramedic).
None of this is terribly earth-shattering, in my opinion... Regular oral hydration based on thirst, self-evaluation (Borg Scoring [1], etc), avoiding IV fluids (but using hypertonic solutions when necessary), etc... All stuff that has been talked about for quite some time now.
[1] https://en.wikipedia.org/wiki/Borg_scale
None of this is terribly earth-shattering, in my opinion... Regular oral hydration based on thirst, self-evaluation (Borg Scoring [1], etc), avoiding IV fluids (but using hypertonic solutions when necessary), etc... All stuff that has been talked about for quite some time now.
[1] https://en.wikipedia.org/wiki/Borg_scale
What about sports drinks vs pure water for endurance activities exceeding 2 hours? I used to only drink water, but switched to diluted Gatorade and found it to hydrate much better (less urination) and reduce soreness the next day.
found it to hydrate much better (less urination)
Usually less urination is a sign of less hydration(?). There are studies that show that some people find it easier to drink the correct amount with a sports drink than with pure water.
reduce soreness the next day
Depending on which Gatorade drink you were using, you may have found some benefit from the carb content that some sports drinks have. There are some theories that easy-to-digest nutrition (which diluted sports drinks can be) help avoid hitting your fat or protein stores. Using fat or protein may cause muscle soreness in some people. I haven't seen any studies investigating this though.
Usually less urination is a sign of less hydration(?). There are studies that show that some people find it easier to drink the correct amount with a sports drink than with pure water.
reduce soreness the next day
Depending on which Gatorade drink you were using, you may have found some benefit from the carb content that some sports drinks have. There are some theories that easy-to-digest nutrition (which diluted sports drinks can be) help avoid hitting your fat or protein stores. Using fat or protein may cause muscle soreness in some people. I haven't seen any studies investigating this though.
It's important to remember hydration is more than just water. Sweating means you lose salts and no amount of water you drink will help, you'll just urinate it out to keep your electrolytes balanced.
So it's quite probable his decreased urination was from being able to retain more water due to the salt intake replacing what had been lost.
So it's quite probable his decreased urination was from being able to retain more water due to the salt intake replacing what had been lost.
Have a read of the original article. It questions that whole premise that losing salts is a problem. IMHO, the evidence in that area is limited and often contradictory.
The evidence in this whole field is pretty scant really. For example, most people think electrolytes help with exercise induced cramps, and yet the only thing with any evidence to support its use is actually pickle juice (!)[1][2]. There is very little evidence to show electrolytes help with cramping in trained athletes.
[1] http://well.blogs.nytimes.com/2010/06/09/phys-ed-can-pickle-...
[2] http://www.ncbi.nlm.nih.gov/pubmed/19997012
[3] http://www.ausport.gov.au/ais/nutrition/factsheets/hydration... (read "What causes cramp")
The evidence in this whole field is pretty scant really. For example, most people think electrolytes help with exercise induced cramps, and yet the only thing with any evidence to support its use is actually pickle juice (!)[1][2]. There is very little evidence to show electrolytes help with cramping in trained athletes.
[1] http://well.blogs.nytimes.com/2010/06/09/phys-ed-can-pickle-...
[2] http://www.ncbi.nlm.nih.gov/pubmed/19997012
[3] http://www.ausport.gov.au/ais/nutrition/factsheets/hydration... (read "What causes cramp")
I'm highly dubious of the article, mainly because it's copywritten to sell a book.
Whilst you're right, the evidence is thin to suggest a lack of sodium is the cause of EAMCs, the recommended treatment is often fluids high in electrolytes.
> Notably, affected athletes often present with normal or somewhat elevated serum electrolyte levels, even if they are "salty sweaters," because of hypotonic sweat loss and a fall in intravascular volume. However, recovery and maintenance of water and sodium balance with oral or intravenous salt solutions is the proven effective strategy for resolving and averting exercise-associated muscle cramps that are prompted by extensive sweating and a sodium deficit. [1]
So whilst there might be a multitude of causes of EAMCs, there seems to be a singular treatment for it. The main hypothesised causes are dehydration, electrolyte depletion or altered neuromuscular control - which is likely caused by electrolyte imbalances.
The article authors claim "Science: There is no scientific evidence that shows sodium (or other electrolyte) deficits in those with muscle cramping." is patently false. There is evidence that sodium deficits increase EAMCs, but so does dehydration (meaning increased serum sodium concentrations), and the main risk indicator is over-exertion.
Yes there's contradictory evidence. However, if you did a generalized study trying to find out why hydraulic pistons seize you would find that there's contradictory evidence because too much and too little hydraulic fluid can seize it, and overworking it can too. Trying to claim there's only one cause is naive.
[1] http://journals.lww.com/acsm-csmr/Fulltext/2008/07001/Muscle...
Whilst you're right, the evidence is thin to suggest a lack of sodium is the cause of EAMCs, the recommended treatment is often fluids high in electrolytes.
> Notably, affected athletes often present with normal or somewhat elevated serum electrolyte levels, even if they are "salty sweaters," because of hypotonic sweat loss and a fall in intravascular volume. However, recovery and maintenance of water and sodium balance with oral or intravenous salt solutions is the proven effective strategy for resolving and averting exercise-associated muscle cramps that are prompted by extensive sweating and a sodium deficit. [1]
So whilst there might be a multitude of causes of EAMCs, there seems to be a singular treatment for it. The main hypothesised causes are dehydration, electrolyte depletion or altered neuromuscular control - which is likely caused by electrolyte imbalances.
The article authors claim "Science: There is no scientific evidence that shows sodium (or other electrolyte) deficits in those with muscle cramping." is patently false. There is evidence that sodium deficits increase EAMCs, but so does dehydration (meaning increased serum sodium concentrations), and the main risk indicator is over-exertion.
Yes there's contradictory evidence. However, if you did a generalized study trying to find out why hydraulic pistons seize you would find that there's contradictory evidence because too much and too little hydraulic fluid can seize it, and overworking it can too. Trying to claim there's only one cause is naive.
[1] http://journals.lww.com/acsm-csmr/Fulltext/2008/07001/Muscle...
It's true it is written to sell a book, but Noakes is a pretty well known sports scientist (perhaps the best known sports scientist in the world?), and a new book by him is likely to gain interest organically.
As well as the increasingly popular "central governor" theory in sports science, he also "invented" the Paleo diet[1]. While I think the Paleo diet's benefits are overstated, there is little doubt that it set a trend towards diets that are more focused on choosing foods that have a high satiability index.
[1]http://en.wikipedia.org/wiki/Tim_Noakes#The_.22Noakes_diet.2...
As well as the increasingly popular "central governor" theory in sports science, he also "invented" the Paleo diet[1]. While I think the Paleo diet's benefits are overstated, there is little doubt that it set a trend towards diets that are more focused on choosing foods that have a high satiability index.
[1]http://en.wikipedia.org/wiki/Tim_Noakes#The_.22Noakes_diet.2...
"the Paleo diet"
The sports medicine perspective along the same lines with respect to all humans other than rich modern westerners would be interesting. Or primates in general.
There would seem to be an obvious life / reproduction advantage in not a body not suiciding by sweating out all the salt, which makes the doctor's argument intuitively appealing.
Infinite water bottles and infinite sugar and infinite salt might or might not help performance, but they're surely not natural, interesting for all non-creationists to consider that all our ancestors evolved specifically not to consume those commercial products... Even if it does help short term (maybe) the long term effects of poking the bear and informal screwing around with tightly coupled systems by consuming enormous doses of unnatural stuff in stressful situations does need to be looked into.
The sports medicine perspective along the same lines with respect to all humans other than rich modern westerners would be interesting. Or primates in general.
There would seem to be an obvious life / reproduction advantage in not a body not suiciding by sweating out all the salt, which makes the doctor's argument intuitively appealing.
Infinite water bottles and infinite sugar and infinite salt might or might not help performance, but they're surely not natural, interesting for all non-creationists to consider that all our ancestors evolved specifically not to consume those commercial products... Even if it does help short term (maybe) the long term effects of poking the bear and informal screwing around with tightly coupled systems by consuming enormous doses of unnatural stuff in stressful situations does need to be looked into.
I'm a believer in pickle juice. Used it at several 8hr+ cycling races. Cramping be damned. Also use take a swig or two after strenuous workouts to prevent cramping later that day.
Yeah, I used pickle juice on the Adelaide Dirty Dozen (4000m+ climbing in 140km). It worked for me, and I have a tendency to cramping. But I also took salt when I felt twinges as well as the pickle juice, so I can't say for sure.
I don't have any actual data to back this up, but anecdotally, I find water and gatorade in a 2:1 ratio 'feels' better the next day (I don't mix it, I just drink two water bottles for every bottle of gatorade). However, my 'long term endurance' activity is firefighting, not running, so there may be some difference there.
I know you should be drinking water, but why avoid IV fluids? Are there certain ones that you should try to avoid more often; NS, LR?
I only ask because sometimes if I'm just not there- hydration wise- and I'm not thirsty I'll throw on 0.5 NS; often I cannot drink enough to replenish the fluids I'm losing.
I only ask because sometimes if I'm just not there- hydration wise- and I'm not thirsty I'll throw on 0.5 NS; often I cannot drink enough to replenish the fluids I'm losing.
"There is no relationship between fluid intake and hydration" is a very odd statement that doesn't appear to be ever followed up on and is on the surface utter nonsense. Is there a missing qualifier here ("fluid intake beyond 'drinking to thirst'"), or am I just missing something?
> Hydration and Thermoregulation
> Dogma: We must drink water in order to prevent heat illness during exercise in hot conditions.
> Science: There is no relationship between fluid intake and hydration, and the incidence of heat exhaustion or heatstroke. The only correlate to core temperature is running pace.
If I'm reading it correctly, there's no relationship between (fluid intake and hydration), and (the incidence of heat exhaustion or heat stroke).
It's a shame English isn't associative.
> Dogma: We must drink water in order to prevent heat illness during exercise in hot conditions.
> Science: There is no relationship between fluid intake and hydration, and the incidence of heat exhaustion or heatstroke. The only correlate to core temperature is running pace.
If I'm reading it correctly, there's no relationship between (fluid intake and hydration), and (the incidence of heat exhaustion or heat stroke).
It's a shame English isn't associative.
How about:
There's no relationship between fluid intake and hydration versus the incidence of heat exhaustion or heat stroke.
Just use a different conjunction.
There's no relationship between fluid intake and hydration versus the incidence of heat exhaustion or heat stroke.
Just use a different conjunction.
Ah, that makes far more sense than how I'd parsed the sentence, and actually fits with the following text.
[deleted]
Reading this makes me think that I did this on my first ultra. The general wisdom is eat/drink before you are hungry/thirsty and do it slowly. I ended up feeling bloated for the last 15 or so miles.
Race day eating is really one of the hardest parts about ultrarunning.
Race day eating is really one of the hardest parts about ultrarunning.
I think eating is a separate matter. Plus, eating (particularly slightly more solid food) takes longer to absorb, so if you eat after you are hungry you are just extending that hunger longer.
That said - I've done many long (8-12hr cycling only or triathlon) events on liquids alone (I prefer infinit.us).
That said - I've done many long (8-12hr cycling only or triathlon) events on liquids alone (I prefer infinit.us).
Similar with cycling.
I did a 120 mile charity ride and was so worried about hitting the wall I over ate and felt nauseous for the last 20 miles.
I did a 120 mile charity ride and was so worried about hitting the wall I over ate and felt nauseous for the last 20 miles.
Same experience on my end for my first ultra distance race. However, feeling bloated is much better than bonking.
While this is interesting, I try to remind myself that I am by no means an ultra marathoner, so in my case I would likely not see any difference between one water protocol vs another.
That is not strictly true. They should have said "don't base your water intake on urine/urination".
Decreased urine volume and abnormally dark urine are both signs of dehydration (early and later stages respectively). They are also both associated with decreased kidney function. But a symptom alone never makes a diagnosis.
In other words, you can't assume you are dehydrated/your kidneys aren't working right based on those signs by themselves. As more an more signs/symptoms become apparent (esp. neuro/GI) then dehydration is likely.