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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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Do IMNA events have scales on the course or only at the end ? I'm doing my first this august and it's going to be hot so I'd like to figure this one out.

Dan
http://www.aiatriathlon.com

http://www.aiatriathlon.com
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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I think Devashish Paul put it right when he wrote, "Please people, find out what you really need to drink." People need to know what their sweat rate is at race pace and calculate how much they need to drink to stay slightly negative in the weight department.

As far performance goes, there's a lot of real-world observational data that faster marathoners and triathletes lose weight. It's the MOP/BOPers who gain a lot of weight and get the most hyponatremia. I did a lot of searching for published data on dehydration negatively affecting performance, and found one paper. It was lab-based, and compared maximal intensity cycling for 5 or 10 minutes (can't remember which) and showed a difference in maximal power output. This kind of anaerobic power output should be irrelevant to the readers of this forum.

I don't fault triguy42 for thinking that 6% weight loss is crazy, but people have done it without adverse effects on their performance or thermoregulation. To paraphrase
Devashish Paul,every person is different. Do what works for you. That being said, I wouldn't be afraid to lose significant weight during competition as long as I felt good. I would be afraid if I gained as little as half a pound.
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Re: Article on drinking too much during exercise [dkv] [ In reply to ]
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In Reply To:
I did a lot of searching for published data on dehydration negatively affecting performance, and found one paper.
There are far more papers than that.
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Re: Article on drinking too much during exercise [triguy42] [ In reply to ]
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The issue of weight loss and fluid status during endurance exercise is complicated by the metabolism of fuels burned.
Carbs and fat combined with oxygen = heat, carbon dioxide, and water.
Carbs are also dissolved in water in the body. This water associated with glycogen is released as the glycogen is burned.
Burning fuels will result in weight loss without changing fluid status, as carbon dioxide is breathed off. This sounds crazy but it can add up over the course of an IronDay to something substantial. So you lose weight just from exercising for so long, so if you lost a bit of weight during the day you would be fluid status neutral. Add in the water liberated by the metabolism and it's like drinking a liter or two of water, so you could be down a couple of kilos without becoming fluid negative.
I'll post a reference if anyone wants.
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Re: Article on drinking too much during exercise [dtreeps] [ In reply to ]
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I bring a scale with me to transition. I leave it next to my bike on races where you rack it yourself, and put it in my transition bag otherwise. Step on it, make sure weight isn't either high or excessively low, off I go. This saved me on on IM race where I was 4lb down off the bike and was getting fatigued/crampy in the last 10-15 miles before T2. I took the first few miles slow and rehydrated. I finished at about 2-3lb down from original weight, which is not bad considering I burned off 10,000 calories (3lb of fat).


Mad
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
I did a lot of searching for published data on dehydration negatively affecting performance, and found one paper.
There are far more papers than that.
Clue me in. I'll read 'em.
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Re: Article on drinking too much during exercise [triguy42] [ In reply to ]
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you can't do that at IMNA can you? Is there a scale in the change tent?

Dan
http://www.aiatriathlon.com

http://www.aiatriathlon.com
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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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.

Sorry my MD credentails aren't sufficient for you. When I attended a CME conference with the "experts" on this subject prior to Boston marathon last year, I learned "Drink when you're thirsty." Wow, that's all they could come up with?!?

As for the waiting issue, if they can have 2000 participants use on course porta-potties without a bunch of waiting in line, I feel sure they could find an efficient way to allow participants to voluntarily weigh themselves without undue waiting. Probably only 10% of the field would even choose to do so.


Coach at KonaCoach Multisport
Last edited by: Terra-Man: Jun 20, 07 10:22
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Re: Article on drinking too much during exercise [NamssoB] [ In reply to ]
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"So if I'm pissing completely clear, but my throat is dry as nails and I'm thirsty - then I'm dehydrated?"
- - Not sure if that's possible, but I suppose it could be. I wouldn't say that urine color or even concentration (electrolytes, vitamins - which are more likely to cause coloration - or what have you) is necessarily related to dehydration because of the time lag factor. What's coming out went in hours ago. As I stated in another post above, your kidneys shut down (at least in part) in response to strenuous exercise, when your body needs to conserve and preserve fluids.
On the flip side, if your throat is as "dry as nails," I'd say you're behind the curve on rehydration. Whether this will affect performance is a matter for some discussion as you've no doubt read above. My own experience (n=20, because I've had a number of my athletes report the same) is that you can get behind the curve during the swim, especially at long course races. Hydrating in advance (by a few minutes) can help with this, while hydrading WELL in advance (an hour or more) seems to be counterproductive as it fills the bladder and depending on your choice of fluids can potentially dilute your electrolytes, possibly causing some loss of same through the kidneys.


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 [Andrew Coggan] [ In reply to ]
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Andrew, I do agree that gaining or losing 10 lbs in a race is a dumb thing to do. I'm not removing personal accountability here, but athletes don't end up doing type of shit intentionally. Most don't even recognize the symptoms in hyponatremia (hpyo or hypervolemic) when they start kicking in. To compound the problem, when an athlete gets to this point the brain function is already impaired, so yes, at this point one might be getting dumber than at rest. Part of doing well in a race is being smart and making smart decisions. That is just part of racing. Slowman would like to now understand the protocol for hydration that would result in good performances, while remaining safe, so that we can all make smart decisions in racing.

Frankly, I believe I have found my sweet spot after discussion with Noakes and it would border on the extreme end of "under hydration" if you looked at it simply by the absolute quantity of fluids consumed.


I'm not going to comment on which cookie cutter approach I used previously, but I do not fall anywhere close to anything that any of the rules of thumb coming out of the so called labs going back to 1990 would suggest. But obviously now that you make this statement, you contradicted your previous one, for without knowing which cookie cutter approach the athlete was following you cannot say if he was following it or not.
Dev: I was just following the cookie cutter hydration recommendation of the lab coat crew[/reply]Andrew: 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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now that you make this statement, you contradicted your previous one, for without knowing which cookie cutter approach the athlete was following you cannot say if he was following it or not.
Dev: I was just following the cookie cutter hydration recommendation of the lab coat crew
Andrew: Not if you gained 10 lbs, you weren't.
[/reply]No, I didn't, because no "cookie cutter" hydration recommendation would ever result in your gaining 10 lbs.
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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Dev, some very interesting stuff in your experience, and some observations that are brilliant.

"20 lbs weight gain (10 from my own stupidity...10 more in the medical tent stupidity....)"
- - Surprisingly much of the "conventional" wisdom (by the athletes and also by the non-experts who staff these races) is that more is definitely better and too much is just enough. Many of us who study sports performance, whether formally or anecdotally or both, are aware that overhydration has it's dangers as well, but most race volunteers and certainly the majority of competitors are woefully underinformed (I shun the term "ignorant") on the parameters, especially one that you noted, ethnicity/climate of origin.

"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!"
- - Which makes you rara avis, but then we knew that already!!

"My family comes from a part of the world where it is 95% humidity and almost 100 degree heat 10 months a year... 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"
- - Give that man a cigar!! You've hit on something sorely underreported and understudied. I can't say that it's necessarily genetic, but it well could be. I've discovered that a great many health issues can be ameliorated by eating the foods that are culturally consistent (what your ancestors ate which is usually dictated by the region and climate in which they lived). As to sweat rates, I know that those can vary depending on the climate where you live, but might well be affected by the climate where your ancestors lived.
My own experience showed this dramatically. I grew up in CA (moderate climate both in temp and humidity) and always had a more or less "normal" sweat rate. After living in Baltimore (stinking hot, although not quite as hot as your parent's land of origin but certainly as humid, reaching +95% in August) and Chicago, my sweat rate increased dramatically. So much so that it was/is totally unecessary (despite anything Dr Coggan may interject) for any sort of testing to verify this. Even while exercising back CA, where I've now lived in the more moderate climate for the past twenty-two years, I still soak through a t-shirt during a hard workout in a very short time.
While living in Chicago, I went to Tucson, AZ (It don't git no drier than that in North America) and came close to suffering heat stroke from dehydration during a mid-morning training run. The heat and dryness pulled the moisture off me at such a rate that I didn't realize I was in trouble until I stopped for water after about 90 minutes (running in a unknown area and not finding water along my route, because I'd have normally taken some water in that much time) I must have drank a gallon without slaking my thirst in the least bit. I ended up walking back and experiencing severe symptoms such as dizziness, confusion, etc.
So what I find interesting is that (thinking out loud, no science here just guesswork) you coming from a line of ancestry accustomed to extremes of heat and humidity might be well prepared genetically or evolutionarily to withstand heat so that your sweat rate under any given conditions could be less than half of what mine is and even lower than mine was prior to living in hotter climates. This would certainly make sense from a logical perspective, although that's totally unscientific. So the temps and humidity in Lake Placid were far less than you were equipped to handle, where the higher-than-CA heat and humidity there would be likely to send me into a flop sweat the minute I got off the plane!!

"Regardless, it is really important for people to find out their real sweat rate."
- - Amen to that!!

"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."
- - Dehydration might be the lesser of two evils, but having experienced it, I wouldn't recommend it! So definitel, *** FIND YOUR SWEAT RATE ***

"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."
- - Another brilliant observation. Listening to our bodies is the way to go.

"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."
- - Right on once again. I can recall running marathons in thirty years ago where aid stations were five miles apart and only had water. I'm pretty sure my performances weren't impacted in any negative way.


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 [dtreeps] [ In reply to ]
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you can't do that at IMNA can you? Is there a scale in the change tent?
I did at IMFL, just stuck it in my T2 bag. One guy next to me at the change building asked to borrow it too. I bet he brings one next time!


Mad
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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OK, this getting brilliant...first time ever on ST that we have stooped to the depths of arguing about which cookie cutter protocol results in which weight gain outcome.....I can't wait to see the study on this one,....A study to end all studies.

Abstract: "The paper describes as cookie cutter protocol under which the average athlete gains no weight over an Iron Distacne event. The paper presents the hydratoin and performance outcome of 2000 moderately trained endurance athlete in an open loop environment, where the weather, pre race diet, in race diet, body fat, blood sodium depletion rate, genetic kidney function of all participants, and susceptability to SIADH is unknown, under weather conditions ranging from 278 to 288 degrees Kelvin and 70% humidity in a Noah's ark style North East Monsoon Deluge. The impact of the use of short sleeve vs long sleeve wetsuits and the initial dramatic dehydration caused by swimming in 80 degree water for over an hour was never analysed as a possible cause for hyothalmus malfunction and early onset of SIADH. The study found that the average Caucasian participant gained zero pounds, however there were outliers in the group who gained as much as 10 pounds. The statistical significance of the outlier group accounting for only 0.05% of the sample size suggested that the outliers fall into the uncertainty ranges typical of such a study"
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Re: Article on drinking too much during exercise [Cousin Elwood] [ In reply to ]
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I'm still in Chicago (maybe we raced against each other) and sweat profusely when exercising, yet I don't feel the need for any water until I've exercised for about any hour, then it is a sip or two. My daughter who also does tris is the same way (except she does not sweat as much as her old man). More than a sip of water while exercising and we get nauseous. So maybe sweat rate is not the key factor.
I have no scientific or medical advice to offer but, based on my experience, I don't think there is a "one size fits all" hydration method.
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Re: Article on drinking too much during exercise [Terra-Man] [ In reply to ]
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"Probably only 10% of the field would even choose to do so."

hey, i'm not trying to diminish anyone's credentials. i'm asking for a sensible, self-diagnosing protocol that works in situ -- during the race itself. you're saying it's just weight. you weigh yourself, during the race. that's the protocol. but as you note, probably 10% of the field would avail themselves of this. i rather think it's closer to 1% than 10%. so, unless you're going to go back to 1981 and make weighing in mandatory, i don't think it's abusive for me to ask whether there's a more expansive protocol.

i note that symptoms of hyponatremia are
cramping, nausea, vomiting, bloating, swelling and tightness of the hands and feet, dizziness, headache, confusion, diminished reflexes. i also wonder whether very low-salt diets leading up to the race, the taking of diuretics prior to the race, being on diuretic medications, are also elements that accrue toward a propensity for hyponatremia during the race.

accordingly, i would think there is a reasonable protocol that would aid the athlete in achieving both optimization of effort and a guarding against hyponatremia. perhaps it starts with what not to do prior to the race (take diuretics? overhydrate?), and what to do pre-race (electrolyte load?). then there's your fueling plan during the race, and finally there are the warning signs of hyponatremia. cannot bloating, or skin color or pallor, or skin tension, or excessive tightness of one's shoes, i don't know... are you saying that these have been discounted by the medical community as user-helpful tools for during-race detection of hyponatremia? and, then, what do you do if you think you're potentially going hyponatremic during an event? do you quit the race? do you quit drinking? do you eat some salt tablets? is that last thing useful before some sort of cascading event makes salt intake no longer efficacious?

i don't mean to disrespect to you and the other MDs, i'm searching for end-user tools (beyond searching for a scale to stand on).


Dan Empfield
aka Slowman
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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Cannot bloating, or skin color or pallor, or skin tension, or excessive tightness of one's shoes, i don't know... are you saying that these have been discounted by the medical community as user-helpful tools for during-race detection of hyponatremia?

In the field, one of the first things we do is attempt to slip a finger under the race wristband or watch. If the person is with it, you ask him if the watch/wristband seems tighter than before the race. You can also look at wedding rings, etc. (And of course, you throw them on the scale, and check their labs. But we are talking about things the athlete can manage).

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and, then, what do you do if you think you're potentially going hyponatremic during an event? do you quit the race? do you quit drinking? do you eat some salt tablets? is that last thing useful before some sort of cascading event makes salt intake no longer efficacious?

Personally, I'd recommend bagging the race, and quitting drinking, and seeing the doctor, and *specifically asking them* about hyponatremia. If they don't know about it, ask to see another doctor. I have seen physicians try to provide IV hydration to people who were clearly fluid overloaded.

In most cases of hyponatremia, the treatment is fluid restriction. In really bad cases, we send them to the ICU on 3% saline IV.

Dr. Philip Skiba
PhysFarm Training Systems
Coaching, Consulting and Technology for World Champions, and You.
Dr. Phil's Books available here
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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Dan, prior to 2003, in Ironmans when I used the "cookie cutter" hydration recommendations, I would lose "definition in my forearms...I never realized what was going on. As I retained water, the intra cellular fluid would go up. Now if I start getting hypervolemic I can see it when I am in my aerobars in my forearms. It has happened a few times in training since, (never in racing because I am on top of it...) when I got really dehydrated early in the workout (due to lack of easily available liquid) and then at a stop, when I pound back liquid, it just stays in by body (SIADH) because the kidneys are trying to protect me from dehydration by conserving the liquid in my body. Usually after I stop the workout, I then have to pee a lot for the next 4-5 hours when this happens.

I've watched athletes blow up at Kona on TV and when they blow (like Macca a few times in the past), they have no definition in their muscles that they normally would...by then, they are retaining liquid. If you are a lean athlete, loss of definintion will tip you off quickly, but as you said, this itself can be somewhat late.

Dev
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Re: Article on drinking too much during exercise [Philbert] [ In reply to ]
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I have seen physicians try to provide IV hydration to people who were clearly fluid overloaded.

Yup, I was the victim at the other end of this!
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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Pretty hardcore Dev sounds like you where very lucky to walk away from that one. Why would the med tent load you up with a IV if you had actually gained weight?

---------------------------
http://www.nunnsontherun.com
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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i'm asking for a sensible, self-diagnosing protocol that works in situ -- during the race itself. you're saying it's just weight.

I'm not sure it exists. If the world's experts tell me to drink when I'm thirsty and I lose 12 lbs. in a race without being thirsty, then something's wrong with those criteria, at least for me. If an objective physician in the medical tent can't tell by looking at someone's skin/body whether someone's hyper- vs. hypo-volemic, then is it reasonable to think that I would be able to accurately make this assessement during the race?

i note that symptoms of hyponatremia are cramping, nausea, vomiting, bloating, swelling and tightness of the hands and feet, dizziness, headache, confusion, diminished reflexes.

Many athletes who are euvolemic experience several of these symptoms during a race, so while they shouldn't be ignored, they're nonspecific and/or unreliable.

I contend that exercise of the duration seen in IM racing throws all kinds of curveballs to the body's homeostatic systems. For instance, I shake uncontrollably for 15 minutes or so within an hour of crossing the finish line. I've been told that the body's temperature regulatory system gets "confused" and thinks your body is cold causing the shivers. I don't shake at all after a half IM.


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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"If an objective physician in the medical tent can't tell by looking at someone's skin/body whether someone's hyper- vs. hypo-volemic, then is it reasonable to think that I would be able to accurately make this assessement during the race?"

then should we officially delete from the list of symptoms
bloating, swelling and tightness of the hands and feet?


Dan Empfield
aka Slowman
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Re: Article on drinking too much during exercise [Slowman] [ In reply to ]
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"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?"
- - Brilliant!! Not being facetious here at all, very impressed. I'm not sure if circumference of the fingers, wrist, ankles or anything else would be good predictors of hydation related problems, but it certainly sounds like it has possibilities. I'll make a not to check that at Vineman, where it will undoubtedly be hot.

"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."
- - Another great point, because I know that I can't tell if I've drank my weight up by 2-3 lbs or dehydrated myself by the same amount. Perhaps if I've varied by 5 or more I'd be able to tell, but 2-3 is certainly enough to cause performance problems and it would be nice to know at that point so as to start moving in the opposite direction.

Interested to see what the guys in the white coats have to say on this.


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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then should we officially delete from the list of symptoms bloating, swelling and tightness of the hands and feet?

Of course not. One should not ignore such signs. But if I'm on the course and have such signs, the one thing I want to know is how much I weigh. Then I know better how to proceed.

Like you, I'm interested in seeing how others do self assessment while they're racing. I have discounted none of it as being worthless. My main point is that it is difficult to do even for someone who is well educated in what to look for, such as myself and Dev.


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [MPB1950] [ In reply to ]
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"I'm still in Chicago (maybe we raced against each other)"
- - Could be. I did the Mayor Daley/Americas/Chicago Marathon from '78-'83 as well as a number of other local runs.

"and sweat profusely when exercising, yet I don't feel the need for any water until I've exercised for about any hour, then it is a sip or two."
- - "Profuse" sweating is a relative term. In Chicago, where the humidity is high, the sweat stays on you, and you might think your rate is high and it may be or it might not be. Try exercising in dry desert heat and you might find your sweat rate is lower than you think.

"More than a sip of water while exercising and we get nauseous. So maybe sweat rate is not the key factor."
- - Or maybe your sweat rate isn't that high. You might be more like Dev, because of years or perhaps generations of exposure to high heat (temperatures, not the Rich Gossage fastball) might have you predisposed to cool yourself efficiently in those conditions.


"I have no scientific or medical advice to offer but, based on my experience, I don't think there is a 'one size fits all' hydration method."
- - Not until one knows one's own sweat rate in ml/min or hour, rather than just thinking that it's high. low or average. Once sweat rates are known, proper hydration strategies can be more intelligently formed. The alternative is to go seat of the pants and hope that you're in the ballpark.

I'm not saying I have the answers, but I'm enjoying pondering the questions. Some very interesting things have been said in this thread.


Cousin Elwood - Team Over-the-hill Racing
Brought to you by the good folks at Metamucil and Geritol...
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