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Re: Article on drinking too much during exercise [Tim Noakes] [ In reply to ]
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MOre great stuff here, but the sodium intakes I was talking about are in the range of 800 to 1000mg per hour...That is what a lot of pros used to do, and are doing today..I always suspected that if taken in pill form, that it wouldn't upset the stomach osmality so much..I used to think why not just put the salt pills in my water bottles, saves the hassle of popping pills while riding. Just assumed that they all go to the same place, but I remember having trouble when I did that, vs just taking the pills..ANd many are coated these days, or in capsules, so makes sense that they might travel farther along before they dissolve, and thus not raise the sodium levels so much in the stomach..

I see your point as to the race across america guy, but perhaps he was taking sodium without knowing if he really needed it in the first place, and thus over such a long period, overdosed. I've taken that much over longer period of times, and had no problems at all.....Of course I don't retain sodium very well at all......
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Re: Article on drinking too much during exercise [monty] [ In reply to ]
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Hopefully I answered your question in my previous post to Slowman.

The danger with anecdotes (which I always take very seriously) is that they are not objective. As I said - what you believe determines what you believe. Your explanation indicates that you believe that you can become hyponatremic by sweating out too much salt and by not taking in enough to replace those losses. This may be so but it has never been shown scientifically. Rather all cases of serious hyponatremia (confusion; convulsions; pulmonary edema; death) occur in those who ingest too much during exercise and who show no evidence for excessively large sodium losses (ie greater than those who finish these races without hyponatremia).

You also believe that salt loss causes muscle cramps since by ingesting salt after races you recover so much quicker. Again there is no scientific evidence that salt loss has anything to do with muscle cramps - which does not mean that this is not the case, just that when we look for the evidence in scientifically controlled studies, we don't find any evidence for this relationship. Then there is the question of the placebo effect of taking something when you are ill and the beneficial effect of believing that the substance will have an effect. The only way you can disprove the placebo theory is by ingesting active and inactive substances without knowing which is which. If the active ingredient (in this case, salt) is more effective than the inactive placebo, then there is scientific evidence for the hypothesis.

To begin to develop an hypothesis from anecdotal observations we need first to collect the relevant data. An obvious experiment to begin to address this question would be to do a prospective study of the outcomes of athletes who do and who do not ingest additional salt during very prolonged exercise. If the salt ingesters do indeed have fewer cramps and finish quicker in this analysis, then one can undertake a placebo-controlled, randomized trial of salt ingestion in the Ironman. We did this some years ago and did not find that there was any effect on blood sodium concentrations. But the study was too small (few funds for these studies) we did not really study performance or the effect on muscle cramps. However my colleague Prof Martin Schwellnus has recently completed a prospective study of muscle cramps in the 2007 South African Ironman - the largest study yet completed - and he has some interesting findings which do not support the salt depletion theory. But I cannot say more until the study is peer-reviewed and published in the scientific literature.
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Re: Article on drinking too much during exercise [Tim Noakes] [ In reply to ]
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I agree that anecdotes are not the end of a discussion. But the ones that do not have axes to grind(sponsors, companies with a financial stake, ect.), should be looked at serioulsy..How many times have professional athletes shown something to be true, in the face of science that counterdicted them earlier on?? I have found that science in my career, has always been a little behind the pro curve. Once science recognizes that something is happening in all those anecdotes, they then set out to prove why it is so, or different from what they earlier believed. As you yourself have said, you have changed your mind over the years about this topic...

As I said earlier, I have done lots of blood tests during my training and racing, and I will have severly low blood sodium and magnesium levels if I don't supplement. SO unless my blood is susceptable to the placebo effect, I need another explination for what's going on in my body.....Thanks again
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Re: Article on drinking too much during exercise [Tim Noakes] [ In reply to ]
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Dr. Noakes, a few additonal questions if I may:

You mentioned several signs of excessive hydration to look for during a race. In your experience, how dependable are these signs? How specific are they? Have you known athletes who noticed such signs and were then able to avoid a catastrophic outcome? Do you have any feel when these signs begin to develop, i.e. at what weight gain level or sodium level?

You addressed the issue of weighing oneself during a race, stating that the body defends itself against change in osmolality rather than weight. However, osmolality can't be assessed on course. Weight is one of the few objective factors that can be assessed during an event. Do you think one could be significantly misled by knowing this information assuming it's accurate?

My feel is that few would dispute relying on thirst to avoid hyponatremia, and while this is the more important issue from a life/death standpoint, optimizing race performance is also of importance. You mentioned your own experience as well as that of Kenyans being able to perform at a high level despite significant weight loss, even in excess of 5% body weight. But these efforts are in the 2-3 hour range, not the 8-11 range we see in IM racing. Do you have any data regarding weight loss of IM triathletes and its effect on performance?

You've made no mention of exercised induced SIADH on this forum, but have rather taken the stance that people are simply overdrinking. Do you think it plays a role?


Coach at KonaCoach Multisport
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Re: Article on drinking too much during exercise [monty] [ In reply to ]
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If taking 1000mg per hour is helpful, it will be very difficult to study scientifically since I doubt that naive athletes would be prepared to do this as part of an experiment. When we did such a study the subjects voluntarily chose to take in much less salt. This suggested to us that there is little drive to ingest additional sodium in naive subjects during an Ironman - ie there is no development of a salt craving during such exercise .

Interestingly salt at this dosage (note that the daily requirement in non-exercisers is about 1-2 grams) may act in a quite different way than we might expect. There are salt sensitive and salt insensitive subjects and the difference may be in the way their autonomic nervous system responds to salt intake. I am not an expert on this topic but it is possible that a salt sensitive person taking large amounts of salt might enhance his or her performance as a result of changes in hormonal balance, activation of the sympathetic nervous system etc that has nothing to do with regulating the blood sodium concentration. At such high doses salt might act in quite different ways than in the range of more normal intakes.
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Re: Article on drinking too much during exercise [devashish paul] [ In reply to ]
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Great post Dev. Glad your still with us :)

I truly appreciate what you are saying.

In South East Asia though , it is so damn hot and thirst feels very real.

What you have learnt and lived to tell is so valuable.

I use INFINITT and supplement with gels and Endurolytes. I have made numerous posts with regard to my thoughts on electrolytes and water useage whilst training and more importantly racing. It is a long process , six years so far and I still haven't mastered it.

Thank you for your post.

"You are never too old to set another goal or to dream a new dream" - Les Brown
"Discipline is the bridge between goals and accomplishment" - Jim Rohn
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Re: Article on drinking too much during exercise [trifan] [ In reply to ]
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This is a good discussion to bring back now that racing season is upon us.
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Re: Article on drinking too much during exercise [R. Armstrong] [ In reply to ]
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In Reply To:
This is a good discussion to bring back now that racing season is upon us.
Well now that you bothered to dredge it up, I took the time to re-read it, and I have to say, the comments of certain parties contain so many mis-statement and mis-attributions as to be comical. So as to not fan the flames, I'll leave it at that, but any one who reads this thread should be aware of that fact.
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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I haven't read it yet, but your post seems to indicate Frank Day is quoted several times...

;)
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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Then, we agree that the ideas should probably be revisited?
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Re: Article on drinking too much during exercise [Terra-Man] [ In reply to ]
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I was at a conference in Boston a couple of weeks ago, and, indeed it appears that the muscle injury induced release of arginine vasopressin, and thus this is really an SIADH issue. With euhydration everything is OK, but overconsumption of water in the face of the AVP is the culprit.

_________________
Dick

Take everything I say with a grain of salt. I know nothing.
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Re: Article on drinking too much during exercise [docfuel] [ In reply to ]
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Hello Trifan and All,

I have a speed display, powermeter, a heartrate monitor, cadence monitor (running and bicycle), altitude monitor, time indication, and so on.

None are necessary to train or race.

Using percieved effort (the Super Compter) can be adequate (and some say better) utilized to run a race. (a heck of a lot cheaper too)

But I like having the information and adjust my effort according to that information (and percieved effort).

Having my weight displayed at the turnaround on the run and at about 2 miles before the finish would be interesting to me.

Trucks can be weighed on the fly. Runners could be weighed on the fly too.

Trucking companies can equip their trucks with transponders that identify them as they approach 21 Oregon weigh stations located around the state. The stations are equipped with the Green Light weigh station preclearance system that can weigh trucks in-motion at highway speed and signal them to proceed without stopping if they pass an instantaneous check of size, weight, height, registration, road-use tax account status, and safety records. Transponders are palm-size devices that are affixed to the inside of the truck windshield. They're available at no charge for trucks that have permanent Oregon registration credentials, three axles or more, and a minimum declared weight of 34,001 pounds. The truck must have been stopping at Oregon Green Light weigh stations an average of at least once per month. Also, the company may not have an "Unsatisfactory" safety fitness rating.

Runners would be weighed as they run across a mat (like reading the chip) and the results displayed on a small billboard just like the traffic speed reading devices.


While weight is not a measurment of serum sodium it could be helpful if you see yourself gaining weight during the race.

For more fun - the runner's pace could be displayed also. (realizing that they had just speeded up a bit to get a faster reading)

The elites weight and speed information would be interesting data for TV fans. (along with their currently displayed bike SRM readings.)

It would be up to each athlete as to how they used the information in regard to whether they are drinking too much or too little. (for the thirst and salt sensing deficient runners)



And the system would provide another profit center for the chip timing industry.

When the BMI police take over the weighing mat could be deployed on city sidewalks to improve the health of the nation.

What do you think?

Cheers,

Neal

Do you suppose the Tanita scale could be modified to show serum sodium levels?

Cheers, Neal

+1 mph Faster
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Re: Article on drinking too much during exercise [trifan] [ In reply to ]
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I didn't read the article but I had this problem before I quit our local Hash House Harriers club.
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Re: Article on drinking too much during exercise [Andrew Coggan] [ In reply to ]
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This thread was recently brought to my attention. Let's just say that I found it...illuminating.
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Re: Article on drinking too much during exercise [donm] [ In reply to ]
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Great article.

I used to work with a group of patients from a large Psychiatric Institution. My six had the diagnosis of 'radiator syndrome' because you could generally find them stretched out over a warm radiator; a response from being hypothermic.

The article about drinking too much and it's effects really reminded me of my six since they all had the particular behavior of 'drinking way too much'. My six would get absolutely 'drunk as a skunk' on H2O if they had any access, then shiver like crazy from a belly full of coldness. We used a weight scale Q1h to try and determine if anyone snuck a drink - as this information determined the metered doses of fluid for the rest of the day. Hyponatremia in these patients was taken very seriously. Sadly, all had terrible sounding hearts, major GI disorders and rather short life-spans.

Truth is...once hyponatremia set in, these folks could barely walk - let alone run. All we could do at this point was to cut them off AA style and monitor for a couple of hours until the symptoms subsided. When I say 'cut off' I mean the Dr's orders were 'nothing by mouth' until they could pass a sobriety test.

Thermo
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