Signs that you need to replace electrolytes and WHO's rehydration formula that you can easily make from common ingredients without a trip to the store.

Do You Need a Rehydration Drink?

If you’re cruising in a hot locale — typically the tropics, but it could even be a trip down the ICW in summer — you may find yourself sweating more than when you lived ashore in air conditioning and losing precious electrolytes in the process.

A bad bout of seasickness, traveler’s diarrhea, or food poisoning can also cause you to lose electrolytes. And once the problem begins, it tends to be self-perpetuating and can become serious unless you take action quickly.

The good news is that most of these problems can be prevented or self-treated with a rehydration drink (I’m not a doctor, and be sure to seek medical help for severe cases).  And more than once, we needed to give our dog a rehydration drink as she coped with the heat as well.

Common signs that you’ve lost too many electrolytes include:

  • Extreme fatigue (beyond normal for the activity)
  • Muscle cramps
  • Headache

Decreased or dark urination and decreased sweating are also common.  In the tropics, the first thing that I’d usually notice was that I’d take a drink and almost immediately break into a sweat — an indication that I’d been dehydrated.

Commercial Rehydration Drinks

Gatorade and Pedialyte are the popularly known sports/rehydration drinks and are available many places.  Gatorade and similar sports drinks are popular as they have nice flavors (and a bunch of sugar).  Both come pre-made, which has the disadvantage of taking up a lot of storage space; Gatorade is available in many places as a powder and I recently discovered Pedialyte powder in the Infant department at Wal-mart (it’s not in the pharmacy — although they did have Pedialyte liquid there — and the pharmacy clerks didn’t know it was in Infants — I found it by chance).

While Gatorade and sports drinks can be adequate before you have any major symptoms, the World Health Organization (WHO) states that they’re not adequate for truly rehydrating a sick person as they have too much sugar (which makes diarrhea worse) and too little sodium.  Pedialyte states that it is formulated to meet medical guidelines.

In many countries, particularly where water-borne illnesses are more common, little packets of oral rehydration salts made to the WHO preferred formula are sold in almost every drugstore, usually quite cheaply.  Most are designed to be mixed with one quart/liter of water, but occasionally other amounts — check the directions.  Even if you don’t speak the local language well, the directions are usually accompanied by pictures showing how much it makes.

If you are seriously ill, these packets work well.  Outside the US, they are usually flavored to some extent, although not like Gatorade.

For “everyday” use before we had any serious symptoms, we mixed one packet with one packet of powdered Tang (also designed to make one quart) to make a half gallon of “Tang-o-rade.”  It tasted pretty good and seemed to ward off any serious problems, depite us living in 90+ degree temperatures without air conditioning and going for desert hikes most days.

However, for some reason, these little packets are frightfully expensive in the US — even on Amazon.  The Pedialyte powder is somewhat cheaper at a little over $8 for 8 packages.

Make Your Own Rehydration Drink

The good news is that it’s easy and cheap to make your own rehydration mix, which is actually very similar to those packets.

The WHO recommended formula is simple:

1/2 teaspoon salt

6 teaspoons sugar (6 teaspoons is 2 tablespoons)

1 quart or liter of clean drinking water

WHO also says (buried in another document, not in the “official” recipe) that you can add 1/2 teaspoon of salt substitute (potassium chloride) OR replace the salt with 1 teaspoon of “Lite Salt” (half sodium chloride or table salt, and half potassium chloride) — or add some mashed bananas to add potassium.  If you’re experiencing muscle cramps, the potassium will make a huge difference in your recovery!

WHO stresses the importance of measuring the ingredients accurately to have the correct mixture — the wrong proportions can make the problem worse.

Mix the ingredients until the sugar and salt are dissolved in the water.  Any portion that’s not being consumed immediately should be kept in the refrigerator if possible.

And if there is any question about the cleanliness of the water, boil it and let it cool before mixing the solution.

And if you’re not seriously ill and want a simple drink to keep you from having problems, you can mix this with a quart of Tang for your own “Tang-o-rade.”

Keep this formula handy — you never know when you may need it and it’s nice as the ingredients are virtually always available.

NOTE: The formula to make your own is in The Boat Galley Cookbook.

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  • Bruce Bibee
    Posted at 28 March 2011 Reply

    It would seem like one could use (filtered?, boiled?) seawater for the salt content and just add the sugar – i.e. potable water + a bit of clean seawater + two tablespoons of sugar. We all get seawater into our digestive system when swimming and snorkeling so this doesn’t seem harmful. Seems to me that the ocean is the original electrolyte and should have everything one needs in about the right amounts.

    • Carolyn Shearlock
      Posted at 29 March 2011 Reply

      Bruce, I know you’re a big fan of using salt water. I just can’t recommend it for drinking any large amount in places that most of us cruise. There is simply too much pollution in it, particularly a lot of petroleum (from boat exhaust) and fertilizer run off, etc. (our watermaker had a special prefilter to capture petroleum and we were quite surprised to see much it caught). These are very hard for the average boater to remove. While we ingest small quantities when swimming and it doesn’t hurt us, it’s a different story to drink a quart or two!

    • Miguel
      Posted at 17 March 2016 Reply

      Bruce, sea water is a hypertonic sol. Most people stranded at sea who drink the sea water end up dead from severe dehydration due to masive diarrhea.

  • Bruce Bibee
    Posted at 09 April 2011 Reply

    I was thinking of getting the seawater while out at sea. I did some quick research and here are the results if you want to check my math and keep it on file.

    1 liter of seawater will weigh 1.027 kg. – containing 27g of dissolved salts. Or 4.2352 teaspoons – say 4.25 to keep things easier.

    100ml will have 2.7g or ab out 3g, which is about a half teaspoon
    1.0 tsp salt (regular NaCl) = 6.375 g or about 6g

    If you are asking how much sodium is in a teaspoon of table salt, the estimation is 2400 milligrams. The recommended daily intake of sodium is 2500 milligrams for healthy adults. Just a side note: 6 grams of table salt is enough to kill you!

    So one needs a one liter bottle and a 100ml bottle (perhaps a screw on cap like on a thermos). Start with one liter of potable water, pour 100ml into the cup and drink it, refill the cup with 100ml of clean seawater and pour it back into the bottle (the equivalent of one half teaspoon of salt), next add six teaspoons of sugar (two tablespoons). This will make a rehydration drink. One might also figure out how many hard candies make up the two tablespoons of sugar. For boaters one can put the hard candies and possibly the 100ml container into the one liter container – you now have a small kit for making rehydration drinks.

    • Craig
      Posted at 30 September 2014 Reply

      Just don’t drink sea water. End of story. It’s nice that you pontificated over the numbers, but really drinking sea water is brain damaged.

      • Caron
        Posted at 08 June 2015 Reply

        The WHO recommends that that if in doubt the salt and water should be no saltier than your tears. Which is the same as saline solution for cleaning/rehydrating eyes, nose ect.
        That being said, I like cooking in saline solution made with high quality sea salt with a swish of kelp. Just watching them look for planes in the ocean gives me the heebeejeebees!

  • jpatti
    Posted at 27 September 2011 Reply

    You really need to add potassium as well as sodium; if you only replace sodium, you may well end up with edema and/or leg cramps.

    A cheap easy way to get potassium is to buy Lite Salt which is half sodium and half potassium.

    I have often made my own sugar-free “gatorade” – basically Crystal Light (or similar product) with sea salt and lite salt.

    If you really want to get fancy, add a pinch of one of the powdered calcium/magnesium supplements as well. The longer you are losing electrolytes, the more important it is to replace these.

    • Carolyn Shearlock
      Posted at 27 September 2011 Reply

      That had always been my understanding — that potassium was needed as well. But the latest recommendation by the World Health Organization didn’t include potassium in the “recipe.” However, when I looked for the citation, I found that now they’re saying that ideally it might include some potassium . . . even though the “recipe” doesn’t include it.

      The Rehydration Project — Recipes

      Thanks for making me go back and check!

  • Andrea Dollins on Facebook
    Posted at 26 December 2011 Reply

    Great info..especialy since I can’t stomach gatorade or any of those so called sports drinks..

  • John
    Posted at 25 March 2012 Reply

    So called “rehydration” drinks are salted water, some potasium, and usually lots of glucose etc. “Gatorade” was originally developed expressly for University of Florida (The Gators) football players.

    Humans sweating and doing physical effort in the hot sun use as much as 25 times more salt (at the extreme, depending on temp and physical effort and length of time) as the same person sitting in an airconditioned house. As a person sweats, they lose required salty body fluids. Those fluids can NOT be replaced with “just water” or fruit juice or any other liquid. The body requires a certain salt level in its blood. Not enough salt in the body, no liquids put back into the blood.

    THE easiest way to replace required salt (and **some**, note “some” potasium) is to drink 6 oz cans of tomato juice. About the same salt/potasium as a quart of Gatorade and a tiny fraction of the calories (football players need calories, most of the rest of us don’t so much).

    IF your body needs the salt, tomato juice/Gatorade tastes GREAT!! If it doesn’t, they don’t. If your body needs the salt and you don’t give it to your body, your muscles will cramp (a serious problem for endurance athletes, even in moderate or even cool temps) and you can even suffer heat stroke (your body stops sweating, your body temp raises and you can die). Lack of required salt is the reason when you are totally thirsty, you drink water and urinate almost as quickly as you drank the water. Your body can’t take in the water without the required salt.

    Athletes will often make their own salted drink by adding salt a little bit at a time to half a glass of water, and keep adding until it tastes salty, then fill the glass with water and drink. Instant adjustment for the “right” amount of salt for the effort the athlete has made.

    BTW, too much potasium is fatal. THAT is the reason the FDA severely limits the amount of potasium available in supppliments. Potasium poisoning is a genuine medical concern in anorexic patients who start to eat again.

    Spring commissioning on my boat includes putting away a bunch of 6 oz cans of tomato juice for the coming hot weather. I drink how much ever tomato juice “feels right” and then glug glug glug two liter bottles of diet soda or water. At the end of the sailing day, I feel as good as when I started.

  • Sue Norris
    Posted at 14 January 2014 Reply

    Great article for easy to understand info about the relationship between fluid loss and rehydration. When we get cramps from exertion ans sweating too much we use magnesium powder. My husband has to be careful about the amount of potassium he ingests.
    In Indonesia they have a great isotonic drink on all shop shelves called POCARI SWEAT. It is very palatable and affordable for everyone. It is very popular. It is very thirst quenching. In Malaysia there is a drink called 100 PLUS. This is similar to Pocari Sweat but slightly fizzy. Both are great when out and about in SE Asia.

    • judith adams
      Posted at 05 July 2016 Reply

      Yes on pocari sweat.

  • Love Sail Social Network And Online Dating
    Posted at 01 July 2014 Reply

    Lemonade and salted peanuts is another good way on a hot day.

  • The Cynical Sailor & His Salty Sidekick
    Posted at 01 July 2014 Reply

    So true about the northern hemisphere. I feel like I need to drink cups of cocoa down in NZ just now to stay warm 🙂

    Posted at 07 March 2015 Reply

    I think its safer and easier to simply buy the product since it ccan be bought in packets now.
    Don’t you? Its not worth getting ill for a couple bucks.

  • MLOsborne
    Posted at 14 March 2016 Reply

    We purchase Gatorade powder in a canister from the local grocery stores. Transfer to an airtight container. Boom! You’re done!

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