Sodium/Salt & Electrolytes


Salt Tablets, Rock Salt, & Electrolyte Capulets:
Experience From - Bob Steele, Bill McCracken, Jennifer ?, Sue Baker, Ed Furtaw, Karl King #1,

Excessive Sodium Intake:
Experience From - Jay Hodde , Karl King #2, Bill Misner, Carlos Guzzo,

For additional information refer to Stomach Problems & Nausea topic.

"Sodium and Dehydration"

by James Raia

Advice based on experience by Karl King. Karl isn't a physician, registered nurse or emergency medical technician. But as a veteran long-distance runner and director of races five kilometers to 50 miles in length, he's seen his share of salt-depleted and dehydrated runners suffering and staggering along wilderness trails.

As the president of a sports drink company, King also has a vested interest when it comes to matters of sodium and dehydration. And when spring turns to summer and runners' needs increase, the Wisconsin developmental engineer's concerns are particularly keen. "After a long cold spring and no chance to acclimate to heat, runners should push a lot of water and sodium from the very start of an ultra," King recently offered in the first of an ongoing series of opinions on an ultramarathon forum on the Internet. "Drink water and take some salt before the race begins. And race directors, please provide water and cups at the start line." King, the race director of the Ice Age 50 - the country's third-largest 50-mile race - and a finisher of the Vermont 100, warns entrants about the dangers of low sodium levels. But he also knows that even experienced runners sometimes don't practice common sense guidelines - even if they're aware of the potential dangers.

Therefore, with the ultra-marathon season in full swing and temperatures rising as summer approaches, consider (with his permission) King's gospel of sodium and hydration:

James Raia is a syndicated journalist and long-distance runner in Sacramento. Comments, suggestions and race information are welcomed and should be sent to 2301J St. #205, Sacramento, CA 95816. E-mail address:

Salt Tablets, Rock Salt, & Electrolyete Capulets

Bob Steele

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

"Hey salt capsules?? Where do you find them."

I make them myself. I purchased empty gel capsules at the local health food store. I fill them with good old table salt. I also mark them on the end with a drop of red food coloring to keep from mixing them up with the other capsules that I have with me during ultras (e.g., BCAA supplements). This really help when trying to identify capsules in the dark with a flashlight!

Bill McCracken

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

I use a product called "Thermotabs" they are buffered salt tablets. Easy to carry and take with water. Any other interested parties, check your local drug stores

Jennifer ?

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

We searched high and low for thermotabs (salt tablets) at the beginning of the summer and learned that they no longer just sit out on the shelf; rather, you'll need to ask the pharmacist to order them. Took a couple of days but no problem. Had real lousy leg cramps towards the end of my run last weekend so chewed one up and took a lot of water with it. Amazing how fast the cramps disappeared. Contents per tablet: sodium chloride 450 mg., postassium chloride 30 mg., calcium carbonate, dextrose, plus some other stuff.

Sue Baker

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

Rock salt can be found in the grocery store in the spice section - it comes in a bag like you would find for a small bag of flour. I have hardly used mine because as soon as I got it the weather started cooling off and I don't feel there is as great a need as there was during the summer. But I'm sure it will keep.

Ed Furtaw

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

I bought a bottle of Thermotabs a few months ago. Drug Store. I like the Thermotabs ok, but when you figure the amount of sodium per tablet - about 179 mg (the rest of the 450 mg of sodium chloride is chloride), and the amount of sodium in sweat (about 920 mg sodium per liter, based on data published by Costill), you would need about 5 tablets per liter of fluid in order to replace the sodium lost in sweat. At several dollars per bottle of tablets, that is an expensive way to take salt. So normally I just add regular cheap table salt to my drink mix on long runs. But I usually carry a few Thermotabs in a baggie in my torsopack pocket just in case I want some salt with plain water.

I had a slightly-painful-at-the-time-but-funny-later experience with a Thermotab. I like the taste of salt in my mouth, so once when I was running, I put one in my mouth and was letting it dissolve gradually. But I coughed or something and inhaled the tablet into my lung or windpipe. I was coughing up and spitting out salt for the next hour! Gross! Next time, I'll just swallow it so I don't end up inhaling it!

Karl King #1

Subject: Salt Tablets, Rock Salt, & Electrolyete Capulets

Peter miles asked how one could get electrolytes for such a run.

Ultra Fit offers a buffer/electrolyte capsule product that should do the job. The product formula supplies buffers to neutralize excess stomach acidity, and electrolytes that provide sodium, potassium and other ions in the proportions found in blood plasma ( which is very similar to sweat in electrolyte profile).

Visit Ultra Fit website.

The concept is that taking a properly formulated capsule or two per hour lets a runner get sufficient electrolytes. If you just get what is in the food and drink along the way, you may not get enough sodium and other electrolytes to make up for what is lost in sweat.

If you have plenty of sodium in your body, it can be added from your blood plasma into the stomach. But when the sodium is sitting on your sideburns, it can't do your stomach any good.

Everybody is OK on sodium when they are standing at the starting line. As they run, sodium is lost in sweat. The goal is to add to your stomach the amount of sodium that is lost during running.

The electrolyte caps also provide buffers that reduce system acidity, and that is something that you won't get from the sodium that is already in the body. Thus, the caps provide sodium to aid stomach emptying, food absorption in the digestive tract, and buffers to neutralize some of the acids that are formed during exercise.

Excessive Sodium Intake

Jay Hodde

Subject: Excessive Sodium Intake

George says:

I felt it was best to follow the directions EXACTLY, and not OD on the pills. They do contain a lot of sodium, which can raise blood pressure if taken to excess.
At about 1000 mg per tablet (don't know exactly), 1 tablet would be too much for a person on a low sodium diet to take.

2 tablets meets the limits suggested by the nutritionists.

There has been shown a correlation between sodium intake and high blood pressure in laboratory animals and in some human studies, but it is also known that the popular press has likely overstated the correlation (to the delight of those making "low sodium" foods). In many individuals, sodium ingestion and increases in blood pressure are NOT correlated. It's the genetics thing again.

I would be more concerned with "chronic" sodium ingestion than the transient high levels obtained by electrolyte replacement during an ultra.

Sports medicine literature has taken the stance that "salt tablets"

for endurance athletes are not recommended. I think this opinion has come as a result of:

  1. Overuse of salt tablets in the 1970's and 1980's -- to the extent that athletes became ill as a result of overingestion.

  2. Instances of hypernatremia and medical emergencies where athletes needed hospitalization to restore their electrolyte balance

  3. The evolution of Quaker's Gatorbarf empire, which has told everyone in america that "sportsdrink" restores electrolyte balance in the exercising athlete. Why take a tablet when some green liquid can do just as good?

My opinion on the tablets? Well, I was skeptical at first, but having used them and tested them, they work. Just be prepared for the sports docs to think you are crazy for using them. (By The Way, I use 1 tablet every 90 minutes during a 100-miler, taking my first one at somewhere around the marathon mark.)

Research on the subject suggests that the average american carries an excess of 8,000 mg. sodium. That translates to 3.5-4.0 hours of sweat losses before sodium loss is remotely a concern. I personally agree that ultrarunners do need to take sodium during ultras from food sources or electrolyte tablets/drinks but not until after 3-4 hours, then with regularity (60-90 minutes)during the event depending on conditions and the individual. Further studies have been published which show hyponatremia occurring more in the back of the pack, where the ultrarunners tend to linger at aid stations and consume more water than sweat rates dictate, becoming water overloaded. Ultrarunners at the front of the pack, in these studies, actually did tend toward slight dehydration, or water short due to their faster pace and higher sweat rate. Both may measure hyponatremic, one due to extreme sweat-fluid loss, the other due to too much intake of fluids. Both may need to take sodium to some extent during the event. It may be possible that some of the "sportsmedicine doctors" and nutritionists are in reality accounting for the "Individual Biochemistry" that in fact does exist during the event in the field where shoe rubber meets the road/trail-ultra event.

Karl King #2

Subject: Excessive Sodium Intake

Bryan raises the interesting question if most ultra runners have an excess 8,000 mgm of sodium.

In theory, ultra runners should have no need to supplement with minerals based on the amount of calories they consume. Yet, studies show runners and other endurance athlete low on zinc and magnesium. Either runners use these minerals at greater than average rate, or their food choices are not good for re-supplying the body.

Before I started using electrolyte caps, I had cravings for salty foods most of the time. Now I do not. Apparently I've satisfied a need for salt that I was often low on.

With 20-20 hindsight, I found signs of low sodium showing up after 1.5 to 2 hours of running. So now I take one cap at the start of a long run and the symptoms are gone.

People vary in their need for sodium. At last year's hot Ice Age, Tom Perry ran very well taking food and drink that were not very high in sodium. Tom wrote to the list to explain that he normally uses very little salt on his food. His body evidently holds onto sodium very efficiently.

That, I think, is the rare exception. Working at the 33 mile aid station, I saw a lot of people with salt on their faces, having a difficult time with the early heat.

So for those who use the electrolyte supplements, I'd suggest starting early and see if you note any difference. If not, you can always wait a little longer before taking some. But for anything my body is using on the run, I'd rather start replacing it a little too early than a little too late.

Especially with water, one should drink early rather than wait until you feel thirsty. If you wait that long, you may not rehydrate until you stop running.

Bill Misner

Subject: Excessive Sodium Intake

Bryan has agreed to submit his personal one-day's intake food for dietary analysis of sodium. While N=1 does not equate exemplifying an average ultrarunner's sodium intake, merely Bryan's sodium intake for 1 day's worth of food. His question revolves around whether or not ultrarunners are typical average Americans, in terms of dietary intake. The query on his one day food intake will show us where he is as an individual ultrarunner regarding sodium intake. My contention is that most of us do in fact not know what we are actually taking in in terms of sodium from food and additives.

For optimal health, normal intake of sodium is between 1100-3300 mg./day for men 19+, and women 19+years, according to the National Committee on Dietary Allowances, while the RDA is 500 mg./ day. Shephard in 1981 showed that the body's daily requirement for sodium to be between 200-500mg./day. Dr. Tim Noakes found and stated that heat-acclimatized runners sweat low amounts of sodium, while unacclimatized-untrained-nonfit runners do lose significantly higher amounts of sodium in their sweat, but both types of sweat analyzed were found to be low in terms of sodium content. Verde et al.,(1982) found that the fit-acclimatized runner sweats 1.8 grams sodium per liter sweat loss, fit but not acclimatized runner sweats 2.6 grams sodium per liter sweat/hour, and the unacclimatized and not fit lose 3.5 grams sodium per liter sweat/hour.

The actual total body content according to Dr. Noakes is 80 grams. Dr. Shephard measured cross sections of westernized dietary practices and found the average intake of sodium to range from 5 grams per day to 20 grams per day. The Low Average he assessed from sources were 3 grams from the foods eaten, and 3-5 grams to be added as condiments or from the salt shaker. In the published Literature such as H.L. Taylor (1943), Sohar and Adar (1964), Brookbank(1929), Dill(1936)Costill(1977), no significant evidence to support intake of copious amounts of sodium exists. Noakes(1985) further suggests that the sodium losses of 6-8 grams in a standard marathon and 10-16 grams in an ultramarathon may be common. Cramps in the heat may also be caused by dilutional hyponatremia(too much water:sodium ratio) by back of the pack ultrarunners who linger at aid stations and drink too much fluid volume(two studies published by Dr. Noakes in 1990 and 1991)(Irving 1991)(Frizzell et al, 1986). Front of the pack elite-types do however tend to slightly dehydrate, but almost never suffer from sodium deficiency. The forementioned studies were concluded at the Comrades Marathon and American ultramarathon. Normal athletes sweat approximately 1.0 liter per hour, while elite Ultramarathoners were found to lose body fluids at 1.2 liters sweat per hour.

The detail described above is what the research says on the only on the subject of sodium-loss in human sweat, however there are also losses of Chloride, Potassium, Magnesium, and of course Chromium, which are necessary to balance the equation of cooling the physiology during ultramarathons. If any one individual athlete depletes or suffers an imbalance of the above minerals, a whole myriad of maladies may both befall and befuddle optimal performance in an ultramarathon run.

This is a superb question!
Bill Misner, Ph.D.
E-CAPS and Hammer Nutrition Ltd.

Carlos Guzzo

Subject: Excessive Sodium Intake

Excessive intake of Sodium Chloride may result in nausea, vomiting, and abdominal discomfort in some individuals, particularly during hard work. Although accepted figures vary according to different experts, it may be preferable to ingest a solution of plain water with up to 2000 mg (that is 2 grams) of common salt per liter. The solution does not taste very well to me, so you may try mixing it with different kind, for example, of a single fruit juice or a mixture of them, which "feels good in your stomach".

You surely know that in very hot places, during strenuous physical work you may lose up to 12-13 liters of water per day, and that MUST be replaced, unfortunately DURING the race. It might help implementing a 4 to 7 days final training schedule in very hot weather, taking care of using more salt during meals after you ended morning or/and evening sessions, and, to me, to increase salt intake during the meals right before starting the race.

You are probably aware of it, but I will mention Gatorade's Coaches' Corner, which you may reach through Internet. At this place you may ask whatever you want, and probably will receive pretty useful answers from coaches, MD's, etc.

Coaches Corner