Why Does Our Body Need Electrolytes?

It seems that there is plenty of information out there about how much electrolyte different products contain, and plenty of electrolyte products, but we’re left with one question:

Why does our body need electrolytes?person cycling

Good question.  And to answer it, let’s go back to some basic science classes.  Sorry if this dredges up memories of angst-filled teen years in high school, but it must be done!

As you may or may not recall, our bodies are composed largely of water.  While the numbers vary quite a bit due to age, health, sex, etc, this amount is approximately 60% water for an adult.    Our bodies rely on water for survival!

But our bodies just don’t have a “water storage facility”… there is water in our muscles, organs, and our blood stream.  And, like there is no water storage, the water is not pure H2O…there are elements (ahem…electrolytes!) within these body parts and systems.

These electrolytes are vital for cellular function!  For example, the sodium/potassium pump, as explained in a previous post.

To simplify things, let’s just look at those 2 electrolytes – sodium and potassium.  If you’re not in balance, you go into “hyper” (too much) state, or “hypo” (not enough) state.  Now we’ve got 2×2, so we end up with 4 States:

  • Hyponatremia
  • Hypernatremia
  • Hypokalemia
  • Hyperkalemia

Now let’s look at those fancy names in a little more detail.


Hyponatremia is a state of low sodium balance within our bodies.  The nasty things this can cause are headache, weakness, nausea, and as it gets more severe it leads to confusion, seizures, coma, and even death.  If you drink a lot of water and don’t add any electrolytes, you can become hyponatremic.  Does this mean you need to always include sodium when you drink?  Absolutely not! But you need to be aware of the balance.

Why don’t we always add sodium?  Because it can lead to:


The first symptom of hypernatremia is thirst.  I suppose this isn’t surprising because your body is trying to add water to dilute the sodium!  Then, confusingly, the symptoms mimic those of hyponatremia.  So, if you always add electrolytes, don’t drink any water alone, or have diarrhea or are experiencing vomiting…you may be getting hypernatrmic.


Let’s turn our attention to potassium.  A low potassium level has the symptoms of irritability, general discomfort, irregular heartbeat, and even paralysis.  Except for paralysis, this is obviously difficult to diagnose in athletes!  Are we irritable and sore from the hill repeats, or is our potassium low?


This one is pretty scary.  It’s usually only caused by extreme kidney problems, but symptoms include heart problems (including stoppage), weakness, numbness, and a tingling feeling.  Needless to say, if you suspect you may have overdone it with potassium and are having these symptoms, seek medical attention immediately!

Now What Do We Do?

Now that we know some of the common issues with “hypo-” and “hyper-” in terms of a couple common electrolytes, what does this mean for us?

It’s very important for cellular function to avoid these extremes.  How can you get there?  Well, if you do an Ironman and don’t take in any electrolytes and it’s a hot day and you drink a lot of water… you can end up hyponatremic.  On the flip side, in that same Ironman  if you take 2 salt pills every 30 minutes all day long you can easily end up hypernatremic or hyperkalmic (depending on the tablet contents).

So, what do we do?  It’s all about balance!  Avoid extremes (I know – that’s a tall order for athletes!), and be aware of your water and electrolyte intake.  Are you starting to get a headache and you haven’t taken in any salt?  You might be leaning towards hyponatremia.  Have you eaten 20 bananas today and your arms/hands are tingling?  You might be hyperkalemic – get to a doctor immediately!

It may sound like common sense…and it is.  However, I’ve found common sense to be rather rare.  I know there’s a famous quote along those lines – if you know what it is drop it into the comments!