Mt. Whitney Portal Store & Hostel Forums General Mt. Whitney Portal Store Message Board Salt: Myth or Fact?

I heard that salt helps to keep you from dehydration. For example, drinking a teaspoon of sea salt with a tall glass of water before you hike.

Does anyone know anything about this?

Water follows salt. This will make you thristier. It takes a while for the salt to get in to your system, anyhow.

Just drink and eat with Gatorade, or =, thrown in midway through your trip and you will be ok. This isn't rocket science and there is no need to complicate it.

Bill

I have never really understood this either. Perhaps it is true since if you eat more salt, you will naturally drink more water. I have noticed when I eat salty food at home (for dinner), I end up getting out of bed all through the night to get rid of the fluids (not fun.) In any event, sweating is an important part of hiking so anything you can do to ingest more fluids may be a good thing.

Remember when coaches in hot areas used to give their players salt tablets to help them dealing with heat/dehydration? Notice that they no longer do that - salt as a treatment has been show to be ineffective. If you want to understand the science, most of what is inside your cells is potassium while table salt is sodium (chloride). Also, your kidney is very effective at filtering out sodium, so it has a very short-lived effect, most of which is to increase blood volume, but not to increase water inside your cells where you need it.

The main reason to have enough salt while exerting yourself isn't to help against dehydration but rather to prevent muscle cramps. The excess loss of sodium, potassium, etc.. will cause muscle cramping. This happened to a good friend of mine on one of our climbs because he only took energy bars. Although they provided him with the fuel he needed, didn't have enough sodium. I gave him some of my gatorade and beef ****y and he was better in about 45 min.

So it's important to take food that has enough salt or something like gatorade.

Salt is VERY important. That is why the Romans used it as money back in the old days. I usually bring a BIG container of Morton's with me. Once when it was icy, I was able to use it to melt the ice. The problem with drinking salt sea water is that the ocean is a couple of hundred miles away from Mt. Whitney, so it would be a long hike to get it. I read a study that was done with experianced hikers that 50% of them used regular water (2 liters) with 6 tablespoons of salt in them, and the others used regular water with no salt. On a 12 mile hike, the salt water users finished about 20% faster. The study said something about that they were in a hurry to get someplace where they could get good water.

There are actually two issues here when discussing 'salt' and exercise: are you referring to sodium or potassium?

It is true that water follows salt - any chemical salt (or osmotic gradient), but clinically, the primary one to play a role in this is sodium. This is why folks who have cirrhosis or congestive heart failure are asked to avoid salt intake because they will accumulate fluid at an even faster rate with a higher salt intake. There are both renal and GI manifestations of this, but as someone previously mentioned, there is more than adequate amounts of sodium in the standard American diet (too much in fact) so this is rarely an issue. If you're really worried about it while hiking, any of those sports drinks will more than cover you. And in this case, more is not always better - taking LOTS of salt will not be more beneficial to you except making you feel very thirsty. Anyway, I highly doubt you'll washout your renal osmotic gradient during the course of a hike.

As for the potassium, this is more of the issue when dealing with cramping/muscle spasms encountered during exercise. Eat a banana, drink some Gatorade/Powerade ...

If that jibberish made no sense, I apologize. Bottom line is that there's a distinct difference between sodium and potassium, but in the end, the usual things that most people do when exercising is enough to take care of the issue. (eat, drink fluids, etc) This is, of course, assuming you don't have diseases that alter your normal physiology - but that's a discussion to have with your own doctor.

Just my $0.015 ...

Table salt can actually be bad in an exercise situation. If you are somewhat dehydrated and ingest sodium chloride, it goes into your body and pulls more water OUT of your cells (the opposite of what you want), which you then pee out.

If you're in a potentiall dehydrating situation (strenuous exercise, high altitude such as Whitney), I would expect ingesting table salt would do more harm than good.

BTW- did you know that because of the osmotic effect with salt, ocean fish actually drink water all the time, while freshwater fish urinate almost constantly! Think about that next time you swim in a lake!!!

You can get salt tablets or a product called cell salt that help with dehydtration. They don't taste like salt and all you have to do is put a few under your tongue. What happens when you sweat is all of the salt comes out of your body in the sweat, a lot of times causing a headache. Also potassium is very good to take with the salt tablets. This should handle dehydration.

Actually, in a dehydrated setting, your kidneys are going to do the exact opposite. When dehydrated, your glomerular filtration rate (GFR) will decrease due to the decreased pressure head from low intravascular volume. This prompts the juxtaglomerular apparatus to increase renin which increases angiotensinogen and therefore, the whole propagation of the renin-angiotensin system (angiotensin I & II, and ultimately aldosterone). You also will activate a separate hormonal response due to the osmotic changes in the intravascular space promoting the secretion of ADH by the posterior pituitary. Both of these will have the net effect of increasing intravascular volume by way of sodium retention (aldosterone) and decreased loss of water in the distal convaluted tubule and collecting duct (ADH).

The addition of salt intake (in usual quantities - I'm ignoring the nut who downs 3 salt shakers with dinner) will not change this dramatically because the kidney is able to regulate how much salt and fluid resorption is necessary to maintain homeostasis - be it sodium retention or wasting. This is, of course, ignoring the potential effects of certain diuretics, congenital enzyme deficiencies, certain disease entities, and other oddities (extensive black licorice ingestion, etc.).

Again, all that jibberish is just to say that the body is quite capable of taking very good care of itself - just eat and drink (of course, within reason) and your body will regulate it's salt balance for you.

There are times when salt intake becomes a crucial issue, but those are usually don't raise their ugly heads unless extreme or unusual circumstances exist.

Why then do those lost at sea become more and more dehydrated from drinking sea water?

ps - not trying to argue with you, just that I had always heard ingesting any extra salt (NaCl type) when dehydrated worsens things through osmosis and this has something to do with why you shouldn't drink the ocean if you are lost at sea. You sound knowledgable, so maybe you can set me straight on this.

The fish info is true though. I am trained in aquatic bio, so I'm sure on that one. Many oceanic animals also ooze salt from various orifices because their bodies are less salty than the sea and thus are always concentrating salt as the fresher water in their bodies leaches out.

Ah ... the seawater bit. Yes, it's true. Do NOT drink seawater - it WILL dehydrate you. This falls under the extreme/unusual circumstance bit, as most folks don't routinely drink things quite that salty.

What happens is that the kidney is able to handle things between approximately 300-1200 osmols in concentration - in terms of diluting or concentrating within those ranges. Some nephrologists will argue as to what that range truly is ... but suffice it to say that seawater is well beyond the human kidney's ability to concentrate - which means that if you drink the stuff, it takes more water on the part of the kidney to deal with it than is present in that volume of seawater, thereby dehydrating you. So drinking seawater on a life raft is not a wise choice.

Of course, if you were a kangaroo rat, you'd have a much longer loop of Henle and probably could handle drinking seawater ... and yup - I recall the bit you mentioned about the freshwater/saltwater fish from good ol' Bio 101 or something.

Hope that helps ...

I have at times on strenuous trips where I sweat a lot on a long hot climb gotten some pretty serious cramps. I have found the salt tablets are very helpful for relieving the problem. But what kind of salt tablets? I read the labels and make sure I get the ones that include a potassium component in addition to just sodium chloride.

Mike