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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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okay, now we have the entire varsity here. finally. (andy, were you under the bleachers cavorting with cheerleaders again during the coin toss?)

what we appear to have are several reasonable, highly educated, folks participating on this thread, and there seems to be some difference of opinion on the literature. in truth, i've seen a lot of literature on both sides. yes, andy is right, there is certainly a plethora of literature that states the ill effects of dehydration.

i guess i have two questions, i'm happy to have anyone answer, and my questions are pursuant to a framing of the issues and the nature of the literature.

first, it seems to me that a lot of noakes' writings are born of the work he's done at races, that is, he performs his "study" at ironman south africa, or comrades, or some sort of ultra ultra distance triathlon. is this what you mean, andy, when you say he hasn't conducted a single experimental study, that the studies about which noakes writes are often just a grouping of 20, or 200, or 2000, "anecdotes" collected an athletic event? does this explain the difference in the views expressed on this thread regarding "literature," that noakes' "literature" consists of these sorts of "field tests," plus his manifestos on hydration protocols, and these are not considered in the same class as that which would be conducted in a lab setting?

second, i wonder if we might parse between performance and medical danger. when we're talking about dehydration, are people talking past each other because noakes' interest is in who lives and who dies, versus the consequences of dehydration or salt intake on performance? in other words, how fair or unfair would it be to characterize noakes' view as: "follow my hydration protocol and you may go slower, but you're also more likely to survive the race with your life."?

Dan Empfield
aka Slowman
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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A few thoughts:

In my experience thirst is not reliable. I lost 12 pounds at IMFL last year without feeling thirsty. Probably slowed due to this in second half of marathon, but my time wasn't far off my potential.

Though the body has mechanisms to regulate sodium balance, they fail miserably in those who suffer catastrophic hyponatremia. SIADH is the obvious culprit.

So what can be done to protect athletes when thirst and the body's homeostatic symptoms aren't fool proof? The answer is availability of scales at aid stations, IMO. They may not be perfectly accurate, but we're trying to prevent catastrophic weight gain on the order of 10 or more pounds.


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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Indeed, it is quite remarkable, especially when you consider that Noakes hasn't conducted a single experimental study to support his claims. OTOH, there are literally tons of data out there showing that performance is negatively affected when one becomes dehydrated by as little as 1-2%, as well as data indicated that replacing 100% of the fluid lost during exercise results in best maintenance of sweat rate, heart rate, stroke volume, etc.

True, and I would not say that the best strategy is to simply allow yourself to dehydrate. However, we should be careful to differentiate between *performance capacity* and *welfare of the athlete*. Most athletes are not going to the trouble of figuring out how to properly hydrate, or even properly prepare for a marathon or IM. Thus, the *safest* advice might be to drink to thirst. Coming to the finish line dehydrated by a percent or two at a slower pace, or even a DNF, is better than the alternative.

Dr. Philip Skiba
PhysFarm Training Systems
Coaching and Consulting for World Champions, and You.
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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second, i wonder if we might parse between performance and medical danger. when we're talking about dehydration, are people talking past each other because noakes' interest is in who lives and who dies, versus the consequences of dehydration or salt intake on performance? in other words, how fair or unfair would it be to characterize noakes' view as: "follow my hydration protocol and you may go slower, but you're also more likely to survive the race with your life."?

It's funny...you wrote this just as I wrote the same thing in response to Andy's comment. I think this "parsing" is particularly important in our sound-bite, "do an IM or marathon on little training for the experience" culture. You aren't going to get your message out to the lay public if you get into the complexities of hydration, electrolytes, etc. Noakes has been successful in getting a very basic, fairly reasonable message into the media which any amateur athlete can remember: "don't overdrink".

Phil

Dr. Philip Skiba
PhysFarm Training Systems
Coaching and Consulting for World Champions, and You.
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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first, it seems to me that a lot of noakes' writings are born of the work he's done at races, that is, he performs his "study" at ironman south africa, or comrades, or some sort of ultra ultra distance triathlon. is this what you mean, andy, when you say he hasn't conducted a single experimental study, that the studies about which noakes writes are often just a grouping of 20, or 200, or 2000, "anecdotes" collected an athletic event? does this explain the difference in the views expressed on this thread regarding "literature," that noakes' "literature" consists of these sorts of "field tests," plus his manifestos on hydration protocols, and these are not considered in the same class as that which would be conducted in a lab setting?

I don't think I would characterize them as anecdotal...he does check labs, he does weigh the athletes, etc. However, such studies are not necessarily at the level of a highly controlled, laboratory investigations. I very much agree with his observations regarding weight gain, overdrinking, and hyponatremia. However, as Andy pointed out, this observation does not support his contention that dehydration is the best strategy.

Regarding the electrolyte issue, I'm not aware of any studies that have indicated that electrolyte supplementation improved performance, or significantly impacted plasma electrolyte concentrations during exercise. (Most studies I am aware of that showed performance benefit included carbohydrates in the replacement beverage, and I would argue this is where the benefit came from.) This does not mean electrolyte supplementation is unimportant, only that I am unaware of data on that point. Andy, do you know of anything off the top of your head? Pubmed came up dry for me.

Dr. Philip Skiba
PhysFarm Training Systems
Coaching and Consulting for World Champions, and You.
Last edited by: Philbert: Jun 20, 07 7:45
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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In Reply To:
it seems to me that a lot of noakes' writings are born of the work he's done at races, that is, he performs his "study" at ironman south africa, or comrades, or some sort of ultra ultra distance triathlon. is this what you mean, andy, when you say he hasn't conducted a single experimental study, that the studies about which noakes writes are often just a grouping of 20, or 200, or 2000, "anecdotes" collected an athletic event?

Essentially, although I wouldn't use quote around the word study, as the approach he's used is certainly a very valid means of describing what actually happens at such competitions. When it comes to why it happens, though, you really need to do controlled experiments, which are most readily conducted in the laboratory, not in the field.

In Reply To:
does this explain the difference in the views expressed on this thread regarding "literature," that noakes' "literature" consists of these sorts of "field tests," plus his manifestos on hydration protocols, and these are not considered in the same class as that which would be conducted in a lab setting?

No, the difference stems from the fact that Noakes is, to be blunt, someone who would apparently be just as happy being known as being right. That is, IMO he is overly willing to ignore data that contradicts his unusual points-of-view (plural, because this is but one of many issues on which Noakes has adopted a position that is contrary to the evidence...as I mentioned before, he himself says that he's an iconoclast).

In Reply To:
second, i wonder if we might parse between performance and medical danger. when we're talking about dehydration, are people talking past each other because noakes' interest is in who lives and who dies, versus the consequences of dehydration or salt intake on performance? in other words, how fair or unfair would it be to characterize noakes' view as: "follow my hydration protocol and you may go slower, but you're also more likely to survive the race with your life."?

No, I think that Noakes is a true believer in his own religon, i.e., he's not tailoring his message to try to achieve some altruistic goal.
Last edited by: Andrew Coggan: Jun 20, 07 7:53
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Re: Article on drinking too much during exercise [Philbert] [ In reply to ]
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In Reply To:
Regarding the electrolyte issue, I'm not aware of any studies that have indicated that electrolyte supplementation improved performance, or significantly impacted plasma electrolyte concentrations during exercise. (Most studies I am aware of that showed performance benefit included carbohydrates in the replacement beverage, and I would argue this is where the benefit came from.) This does not mean electrolyte supplementation is unimportant, only that I am unaware of data on that point. Andy, do you know of anything off the top of your head? Pubmed came up dry for me.

Ron Maughan was at that same UK Sport meeting that I attended earlier this year, and IIRC he discussed a study showing less of a decline in plasma sodium in subjects consuming a salt-containing sports drinks than subjects who drank only water. Beyond that, though, the details escape me.
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Re: Article on drinking too much during exercise [cdw] [ In reply to ]
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"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."
- - Absolutely agree. Under strenuous exercise, the kidneys will shut down, at least partially, preserving fluid volume because so much is lost through sweat. I think the problem is caused by people hydrating excessively prior to racing.
I've found that if I take in a lot of fluids in the pre-race hours, I'll be feeling the need for a pit stop before the race is over. I've also found that (for me) if I drink 10-16 oz. of (used to be whatever I was racing with, but this year it's Infinit's pre-hydration formula) just a few minutes before entering the water, then I don't feel thirsty and can start taking in my drink mix on the bike to hold off that thirst without feeling any urge to empty my bladder. In fact, I usually don't even head for the head after the finish line until I've downed a few liters of fluids and have been just wandering around for a half hour or more.


Cousin Elwood - Team Over-the-hill Racing
Brought to you by the good folks at Metamucil and Geritol...
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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Slowman, after a near death overhydration 20 lbs weight gain (10 from my own stupidity...10 more in the medical tent stupidity....) at IMLP 2003, I had a fair amount of discussion with Noakes on this topic. While others can sit with their lab coats on with a smug look on their faces from their "highly accurate" white tower academic papers, I'll go with the field studies from Comrades, Ironman South Africa and Ironman New Zealand that Noakes has conducted.

I followed the usual hydration to death routines that were generally prescribed and never figured out why I felt like crap for my first 10 Ironmans....then after talking to Noakes, I realized that I could actually do a hot Ironman like Kona on 4 bottles of Gatorade on the bike and some cups of gatorade and coke on the run still post a PB!

My family comes from a part of the world where it is 95% humidity and almost 100 degree heat 10 months a year. There, you cannot leave salt in salt shakers....it turns to slush in a day. You have to add grains of rice to keep the salt from liquifying from absorbtion of humidity from the atmosphere. Not sure if it is genetic, but everyone in my family have really low sweat rates. Must be an evolution thing for surviving in such a climate....I don't know....

Regardless, it is really important for people to find out their real sweat rate. Head out for a 90 min run and replenish with zero water in a variety of temps and do before and after weigh ins to find out what you really need to replenish. Under replenishment will not kill you.

Like you said, yes performance might drop marginally and Dr. Coggen points out due to mild dehydration, but it is extremely rare that fit athlete will die from dehydration. The likely outcome is that the athlete slows down a bit as a form of self preservation. However, we as a species only drank water when we needed it, using thirst as an indicator. Overhydration is not really a part of human evolution. Man did not drink when he was not thirsty. Death from hyponatremia is very real.

I've spent 4 years recouperating from the post concussion symtoms resulting from the intracellular fluid putting pressure on my entire brain encased in a physically fixed volume skull. I'm lucky that I did not die from a herniated brain stem. I'm also lucky to not have died from central pontine mylenolysis from rapid correction of sodium levels after this all occured. I did have nerve damage and lots of short term memory issues, nausea and deterioration of fine motor skills for a long time that have finally largely cleared up, although I go through a day or two a month when it is still an issue.

Please people, find out what you really need to drink. An aid station every mile in most marathons or Ironmans, especially for slower finishers who actually can take in entire cups of liquid (hard to do for 7 min mile runners....) is largely overkill. A bottle every 10 miles on the bike is likely too much for most people...but people take all this in cause the aid stations are there. Noakes found in his "real world tests" that if they reduced the number of aid stations, they actually ended up with less athletes in the medical tent. In fact, and my memory may not seve me perfectly, in one year at Ironman New Zealand, they treated zero athletes with IV's despite less aid stations than IMNA events.

Peace...be safe....those aid stations could actually kill you....but as a bare minimum, they may be taking away from your race day performance...

Dev

Edit: Last year at Ironman Hawaii, I weighed in race morning at 140 and ended the race at 138, on 4 bottles of Gatorade on the bike, and whatever I had off the course every other mile on the run. Please keep in mind that my Wed weigh in was 138 too. The final 2 lbs of weight that I gained was from all the water you retain when you carb up. Conversly, when I gained the 10 lbs in a 50 degree rain storm at IMLP 2003, I drank in the order of 8 bottles on the bike and then on the run, was drinking a coke and gatorade EVERY aid station. Then I slowed to a walk and was drinking chicken broth....way too much for my body!!!
Last edited by: devashish paul: Jun 20, 07 8:32
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Re: Article on drinking too much during exercise [Cousin Elwood] [ In reply to ]
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I think the problem is caused by people hydrating excessively prior to racing.

Agree. And not just the day of, but in the days leading up to race day. I wonder also if this contributes to hyponatremia, i.e. coming to the start line relatively hyperhydrated and depleted of sodium. Does anyone know if this has been considered/studied in those who have developed hyponatremia?


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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In Reply To:
Slowman, after a near death overhydration 20 lbs weight gain (10 from my own stupidity...10 more in the medical tent stupidity....) at IMLP 2003, I had a fair amount of discussion with Noakes on this topic. While others can sit with their lab coats on with a smug look on their faces from their "highly accurate" white tower academic papers, I'll go with the field studies from Comrades, Ironman South Africa and Ironman New Zealand that Noakes has conducted.
You might mock me as "someone who sits in their lab coat with a smug look on their face", but at least I've never drank so much that I actually gained weight while training or racing. ;-)
Last edited by: Andrew Coggan: Jun 20, 07 8:32
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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Fair enough...I was just following the cookie cutter hydration recommendation of the lab coat crew...now I go with what Noakes recommends and I'm faster at 41 then I was when I was 25!
Last edited by: devashish paul: Jun 20, 07 8:35
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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In Reply To:

Indeed, it is quite remarkable, especially when you consider that Noakes hasn't conducted a single experimental study to support his claims. OTOH, there are literally tons of data out there showing that performance is negatively affected when one becomes dehydrated by as little as 1-2%, as well as data indicated that replacing 100% of the fluid lost during exercise results in best maintenance of sweat rate, heart rate, stroke volume, etc.[/reply]The above quote from dkv personally scares me:
"As a group, people who lost 6% of their weight had no difference in rectal temp compared to those who lost only 2%. 6% is 10 pounds for me! More weight loss also trended towards faster times (so it's not as if they were working less and generating less heat)."

6% loss?!?!?!? At ~160lb that would be about 150.4lb for me. If I've been out running for a long time and not keeping track of water I can easily lose 2-3lb. But at 155lb I stop sweating almost entirely and am forced to walk. This has only happened two or three times over the last 5 years, but I can't even IMAGINE losing nearly 10lb. Something is seriously wrong with the above study, as it totally contradicts everything I've ever read, and what Andy just said above. I can understand body temperature not being substantially different, as the people who are better hydrated are performing better and their bodies are generating more heat, etc. But the above study seems to say the opposite, which makes little to no sense.





Mad
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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Dev, I'm the Yin to your Yang, or maybe I'm the Yang, but whatever. My people come from a long line of extremely pale, heat averse people. I need about 40oz of fluid per hour when the temps creep over 85 or so.
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Re: Article on drinking too much during exercise [vitus979] [ In reply to ]
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Strange. So if I'm pissing completely clear, but my throat is dry as nails and I'm thirsty - then I'm dehydrated? Maybe some would debate what the term "thirsty" really means.

- - - - - - - - - - - - - - - - - - -
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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In Reply To:
I was just following the cookie cutter hydration recommendation of the lab coat crew
Not if you gained 10 lbs, you weren't.
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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In Reply To:
I followed the usual hydration to death routines that were generally prescribed and never figured out why I felt like crap for my first 10 Ironmans....then after talking to Noakes, I realized that I could actually do a hot Ironman like Kona on 4 bottles of Gatorade on the bike and some cups of gatorade and coke on the run still post a PB!
Regardless, it is really important for people to find out their real sweat rate. Head out for a 90 min run and replenish with zero water in a variety of temps and do before and after weigh ins to find out what you really need to replenish. Under replenishment will not kill you.
I think it's fair to say that hydrating like mad without having a clue of your normal sweat rate is borderline suicidal. :) I did this experiment myself on the bike a few years back by riding at race pace for 30 or so miles and drinking a known volume of water. Weighed before and after and found my sweat rate in the Floriduh sauna to be in the range of 1.9L/hr (which is on the high side of normal IIRC). This has driven my hydration plan for hot and humid days. My sweat rate on cooler days is dramatically less, so I have to pay attention to how much I am sweating. After 3 years of religiously checking pre and post workout weight I know have a pretty good handle on my hydration level and can usually maintain it within 2lb of "normal."

Here's a followup question on salt and hydration for the experts. I typically sweat a lot as mentioned above. In order to take in enough water I usually take a Thermotab (450mg NACl) or Saltstick cap (550mg NaCl) about every 45 minutes and this seems to help a lot with gastric emptying, especially on the run where I can go from a sloshing stomach to normal in about 5 minutes. If I take in the same amount of water without the salt it tends to just sit in my stomach and I get bloated. Is there any literature to actually support my n=1 observations?


Mad
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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The cookie cutter hydration recommendations floating around do not take my low sweat rate into account.

Andrew, you are a smart guy, but unless you were there, in the situation on that day in 2003, don't pretend to know more about the situation on the limited information you have read to this point. Noakes is not the only one that I spoke with after that day. I consulted with numerous medical professionals, specializing in everything from kidney to brain function, who I'd argue have a better grip on this topic than most self professed "ST experts of all domains".

Dev
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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i suspect when noakes shoved a thermometer up petr's ass it registered pretty red.

The thermometer or the ass?
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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well, i think we've figured out what not to do: gain 10lb during a race, or lose 10lb during a race. i also am quite happy to have various sports doctors liaise with race promoters in order to find a consensus as to how many aid stations ought to be on the course, and how to treat distressed athletes post-race.

all this leaves us with the most important question for those on this forum: how to recognize the symptoms of hypervolemia or hyponatremia during the event itself, and to hydrate properly (instead of simply erring on the side of underhydration). for all practical purposes, i'm still finding myself thinking, when i parse the statements by the noakesians, that they're looking at this strictly as a safety issue. me, i'm also interested in performance. i mean, using this same reasoning, here's my protocol for bike safety: go slower on descents. your performance may suffer, but you're more likely to live or escape serious injury.

i'm hoping that the noakesians can provide the end users with a hydration protocol that is both performance and safety specific.

Dan Empfield
aka Slowman
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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In Reply To:
The cookie cutter hydration recommendations floating around do not take my low sweat rate into account.

And what "cookie cutter" recommendations were those?

In Reply To:
Andrew, you are a smart guy, but unless you were there, in the situation on that day in 2003, don't pretend to know more about the situation on the limited information you have read to this point.

You don't have to be very smart to understand that drinking so much that you actually gain weight while racing is a pretty dumb thing to do...
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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all this leaves us with the most important question for those on this forum: how to recognize the symptoms of hypervolemia or hyponatremia during the event itself

Weight is the only reliable and practical way to assess on-course hydration status. Bathroom scales aren't expensive.


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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You don't have to be very smart to understand that drinking so much that you actually gain weight while racing is a pretty dumb thing to do...


You don't even have to think at all -- just follow some of the articles that "coaches" have written where they recommend taking in a ga-jillion (that's a scientific term) calories during a race. Then people wonder why they had "stomach issues" during the race. Hey, I know... You need to try "BrandX" instead! It's got Mega-SuperLow Osmality vectors!


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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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You don't have to be very smart to understand that drinking so much that you actually gain weight while racing is a pretty dumb thing to do...

Unfortunately, the ADH system doesn't know smart from stupid.


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [Terra-Man] [ In reply to ]
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"Weight is the only reliable and practical way to assess on-course hydration status. Bathroom scales aren't expensive."

this takes us back to 1981. ironically, the only thing that mattered to the IM organizers back then was whether i was going to lose 10% of my body weight. so they weighed us 5 times during the event. in point of fact, they ought to have been worried about my gaining weight, eh? i started that race at 161 lb, and got up to 163lb during the race, eventually finishing it at 158lb.

i rather think there may be other things that are harbingers of weight gain, such as circumferences. is your ring, or your watch, fitting tight, with your skin bulging out around it/them? what about skin texture and color? come on! is weight gain it? let's face the reality that we're not going to have a line of people waiting to stand on the scales at the weigh stations, like a caravan of tractor trailers on the interstate. let's have the experts "weight in" on the other signs of hypervolemia an athlete can recognize during an event.


Dan Empfield
aka Slowman
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