The grave risk of hyponatremia should probably not be news to anyone on this site, but quotes like the below make it a good read…
“Everyone becomes dehydrated when they race,” Dr. Noakes said. “But I have not found one death in an athlete from dehydration in a competitive race in the whole history of running. Not one. Not even a case of illness.”
On the other hand, he said, he knows of people who have sickened and died from drinking too much.<<<<
I had a case of hyponatremia in 2003 in an Ironman and almost died in the medical tent when I got 4 extra IV’s pumped into me. I ended up with a full brain concussion from the extra fluids and still have post concussion effects two years later. I consulted extensively with Dr. Noakes after that incident. It is interesting to note that at the Comrades Marathon a 90K running race in South Africa with almost 10,000 runners, they treat zero people in the med tent with IVs for the reasons that Dr. Noakes mentions in his various publications in the medical journals. Humans, to some extent have evolved to physically operate effectively in state of dehydration and bounce back with no ill effects after nourishment and rest.
I have just started to struggle with this condition in the past couple of years. I have learned that you can purchase salt tablets and take them during long workouts or races. This is what I plan to do. Hopefully this will keep me out of the medical tent. Up until this point I would look for “snack foods” (read: unhealthy) with the highest sodium content avalaible and eat them before long workouts or long races. Good luck everyone and stay safe.
Rocho, you can also add a teaspoon of table salt to your bottles of gatorade (train with it to get used to taste) and you can even just bring table salt along in a zip lock baggie for training or even the section of a longer race. Ideally though, use salt tabs and limit your fluid intake only to when you are truly thirsty.
This winter for a 100K XC ski race (6:17), all I had for fluid was just under 2L of salted Gatorade and I was fine. For a half Ironman, even in warm conditions, all I tend to need is two large bottles on the bike and one small bottle on the run (total 2L). Next time I do an Ironman, I will be much better prepared, on this front, especially if it is in rain and cold, when I need even less.
Thats interesting, but even drinking too much Gatorade or other electrolyte drinks can cause this? I thought that was the purpose of these drinks, that they contain sodium and carbohydrates. Or is it they are at such low concentration levels that over time, too much will still dilute??
Slightly OT, but I had a client (I’m a labor attorney) who had an employee who was notified that he had been selected for a random drug screen. He had about 2 hours notice before he was due at the lab. He was observed at the water fountain for an inordinate amount of time (apparently believing he could dilute his urine enough to fool the drug test). When he got to the lab, he was escorted into a room to make his urine deposit. When the nurse came back, he was dead. Diagnosis: Hyponatremia. They found some empty blister packs for diuretic pills (apparently also taken in an effort to dilute his urine/blood) in his car. Sad story.
Kittycat, in dummy layman’s terms, for every 500 mL bottle of Gatorade that you mix with a scoop of gatorade you need a FULL teaspoon of tablesalt to maintain blood sodium levels over the longer races. Any less and you’ll dilute the sodium concentration in your blood over >3 hours, especially if you are a big sweater of even if you are not sweating and drinking a lot, you’ll absorb water into your blood without the right amount of sodium (thus the Hypo…).
You can can have hypervolemic hyponatremia (this is when you swell up like the Michelin man…the dangerous type ) or hypovolemic hyponatremia (when you are dehydrated and also low in salt). My understanding is that the latter is not too dangerous…ie you won’t sever your brain stem, you’ll just have lots of cramps and slow down.
You are right in that thr gatorade salt levels are not high enough to prevent hyponatremia with high amounts of intake. The gatorade had less sodium than body fluids and it is therefore a net dilution effect.
Assuming of course that your kidneys aren’t getting rid of the extra water fast enough.
The new gatorade endurance should lessen the effect though, it has more sodium.
The blurb in my local sports page on this study said that the runners at risk in this study were drinking so much that they gained 4 or more pounds during a race. How many people gain significant weight during a race or during workouts? During workouts, I tend to lose between .5 and 2 pounds on a run (depending on length, heat and humidity). I tend to stay more or less even (.5 pound either way) on the bike during workouts. Have never drank during swim workouts so always lose some weight there. I’ve never finished a workout weighing pounds more than when I started. You must really be working on pushing the fluids to accomplish that.
Now, I have weighed a few pounds more the day after a big race than the day before, but only when I have celebrated by eating far too much really bad food afterwards (like a whole deep dish pizza or something similar), not because I drank too much during the race.
CTL, if you are admitted to the med tent of your local Ironman North America event, they weigh you. They also weigh you before the race and take the difference. Lots of dudes gain weight during the race.
If you lose definition in your muscles (ie you can’t see the veins in your arms, given that you could pre event),then you are gaining liquid and diluting your blood sodium.
The reason I asked the question about weight gain was that, given my experience, it’s surprised me to read that people gain weight during a race. My experience is limited to marathons and much shorter tris than an IM, but the article was about a study conducted during a marathon, not an IM. Fro example, on a really hot or humid summer day, I might end up drinking almost a gallon of water and gatorade during a 20 mile run, but I still end up losing 2 pounds or more during the run.
Now, I think you have much greater risk of hypoatremia during an IM because it is a much bigger endeavor than a mere marathon and so much more can go wrong. Given that you start with a 2.4 mile swim (I probably lose a pound swimming that far in a pool), it’s still a little surprising to me that people weigh significantly more during an IM than before the race. Given how easy it is to drink during the bike, it’s a lot more understandable, though, than gaining 4 pound during a marathon.
Your particular experience, almost being killed by what seem to have been medical malpractice, is a lot different from both situations.
“Now, I think you have much greater risk of hypoatremia during an IM because it is a much bigger endeavor than a mere marathon and so much more can go wrong. Given that you start with a 2.4 mile swim (I probably lose a pound swimming that far in a pool), it’s still a little surprising to me that people weigh significantly more during an IM than before the race. Given how easy it is to drink during the bike, it’s a lot more understandable, though, than gaining 4 pound during a marathon.”
Most Ironman folks at risk of hyponatremia are in the >12 hour crowd because:
a. they are out there for longer
b. there rate of work is lower which means they are typically sweating at a lower rate per hour
In an Ironmman, you get an aid station every 6 miles or so on the bike. This adds up to 15-20 stations during the bike. It is easy to drink a whole bottle every couple of stations if you lose track and try to stay “hydrated”. That would be in the range of 10 bottles on the bike course alone. On the run, the speed is much slower than a marathon, so people absorb way more per station. In fact in Ironman, you usually see a large gaggle at each station of people standing around and eating/drinking. In marathons, it is rare to stop. Most just shuffle through and get a gulp. In Ironmans, there is an aid station every mile (26 of them). Few marathons have that many stations. Realistically, three or four aid stations on the bike and 6-10 on the run would be more than sufficient, but few RD’s will actually take Dr. Noakes’ advice. Realistically, during a 100 mile training ride do you know of anyone that stops 10 -20 times to get liquid ?
Reducing the number of aid stations (or as an athlete, skipping the majority of them) is the easiest way to prevent hyponatremia . Drink when you are thirsty only.
Dirtball, a friend of mine trained with Cole Stewart’s group in Austalia a few years back. Those of you who have been in Australia’s Gold Coast in the summer know how stinking hot it can be. Anyway, aparently Cole was getting his athletes to try and put as much salt as they could in their sport drinks. Some used as much as 1 tablespoon and felt great. It does take some getting used to.
This Monday when I am sitting around for two hours in Hopkinton waiting for the Boston Marathon to start, I’ll be sucking back a bottle of gatorade with 1.5 teaspoons of salt in it :-). I find race morning salt consumption helps.
This is a really good thread, and it is nice to see the subject of hyponatremia getting more exposure in the lay press. The important thing to remember is that dehydration will slow you down, but hyponatremia will kill you. DP, I am glad to see you made it out alive.
As far as adding salt to beverages, Noakes would disagree. His data showed no relationship between taking salt tablets and hyponatremia. (You can look up the abstracts on pubmed by searching for him and a guy named Speedy. And no, that isn’t a joke ;^) ). What they did show (IIRC) was about a half kg of weight gain in the athletes who took the tablets, suggesting they retained more fluid, which would make sense. (In general in the body, water follows sodium…if I give you a drug to make your kidneys allow more salt into your urine, you’ll pee like a racehorse. If I give you a large dose of salt, I can get you to retain more water).
Now, at the most recent ACSM Team Physician’s course, the fellow presenting the hydration talk still was not willing to put all his eggs in Noake’s basket. However, he did make the point (for which there are a lot of anecdotal reports) that people who suffer from whole body cramping during events in the heat often solve this problem by taking electrolyte supplements in addition to usual sports drinks.
I have not seen a lot of this, but I have taken care of athletes who have reported this to me, and really, who am I to argue? I’d say they are worth trying if you are one of those people. Otherwise, I think smart money says drink appropriately (i.e. with your thirst), certainly don’t force fluids down, and that you can probably lay off the salt supplements unless you are one of those cramping people etc.
Minor point: Salt in sweat varies trmendously between different people. That doesn’t nessecarily mean you have a problem if you are a very salty sweat-er, so don’t go looking for one if you aren’t having trouble.
Shameless plug: I get into a lot of the supplement issues (based on the scientific literature) in my book. But you can find a lot on your own using the internet and the library at your local university/hospital and save the ten bucks :^).
I started training with diluted Gatorade with added salt. I’m a salty sweater and I also am a high volume sweater as well. Basically, I am a sprinkler system for sea water when I exercise. I found that adding salt does seem to make me feel better.
if I understand you correctly, added salt may help reduce cramping in the event of hypovolemic hyponatremia, but it may actually increase your propensity to store liquid in the event that you hypervolemic. Its only when you stop/slowdown and your kidney/hypothalmus systems comes back to normal that the additional salt will help you pee out the excess fluid ?
By the way, I have a super low sweat rate, and the Ironman where I became hyponatremic was cool with lots of rain. It was also 2 hours slower than my usual times.
Yeah, more or less. That said, the fact that the the cramping people are suffering from hypovolemic hyponatremia is really speculation, as to my knowledge there are no studies showing that. (That doesn’t mean they don’t exist. I just have not seen one.)
Regarding the whole kidney bit…Noakes has argued that one possibility is that there is a derangement of water handling by the kidney during exercise. However, I have not read anywhere that the excess salt may help you pee off the fluid once things normalize.
In my mind, it is similar to something called SIADH, or the syndrome of inappropriate ADH secretion. ADH (which I am sure you know, I’m just saying for everyone else) tells your kidneys to retain water, and people with this problem get hyponatremia because they are drinking, but not peeing enough. The treatment is simply fluid restriction (in most cases…the really severe ones end up in the ICU getting 3% saline by IV). They pee off the excess fluid, and their sodium normalizes.
And from the history you give there, it looks like you are the poster boy for Noakes’ efforts to educate people. You ought to go on the lecture circuit or something ;^)