Electrolytes 101: What They Are and What Each One Does

"Electrolytes" is on every hydration product in the store, but most labels never explain what they actually are. Here's the plain-language version: what electrolytes do, the five that matter most, where you get them, and how to tell a good electrolyte product from a sugary one with a mineral sprinkle.

What electrolytes are

Electrolytes are minerals that carry an electrical charge when they dissolve in water. That charge is what lets them do their jobs: moving fluid in and out of your cells, carrying nerve signals, and making muscles contract — including your heart.

Your body keeps them in a tight balance. You lose some every day, mostly through sweat and urine, and you put them back through food and drink. Most of the time, that balance takes care of itself. It gets harder when you lose a lot quickly — a long, hot shift, heavy gear, hard physical work.

The five that matter most

Electrolyte	Main job	Common food sources
Sodium	Holds water in your body and maintains blood volume. The one lost most in sweat.	Table salt, most packaged and restaurant food
Potassium	Works inside your cells to balance fluid; essential for muscle contraction and nerve signals.	Potatoes, beans, bananas, leafy greens
Magnesium	Helps run more than 300 enzyme systems, including energy production and normal muscle and nerve function.	Nuts, seeds, whole grains, leafy greens
Calcium	Bones, but also muscle contraction and nerve signaling.	Dairy, fortified foods, leafy greens
Chloride	Travels with sodium to keep fluid in the right places.	Table salt

How you lose them

Sweat is the big one. It's mostly water, but it carries electrolytes out with it — mostly sodium and chloride, plus smaller amounts of potassium, magnesium, and calcium. How much you lose varies a lot from person to person, and it goes up with heat, humidity, heavy clothing or PPE, and how hard you're working.

That's why drinking plain water all day can leave you short on a long, hot shift: you're replacing the fluid, but not what left with it. We break down that difference in Hydrate vs. Replenish.

Do you actually need an electrolyte product?

Honestly, not every day. Most Americans already eat more sodium than they need, and regular meals cover a lot of the rest. On a normal day with light sweating, water and food are enough.

Electrolyte products earn their place when losses outpace what you'd normally eat — several hours of sweating, a double shift, working through heat without a real meal break. Federal workplace guidance draws the line the same way: water for shorter stretches, and a drink with balanced electrolytes when sweating goes on for several hours.

How to read an electrolyte label

Next time you pick up a hydration product, flip it over and check four things:

• How many electrolytes are actually in it? Many products cover sodium and potassium and stop there. Calcium often gets left out.
• What forms are they in? The same mineral comes in cheaper and better-absorbed forms. Magnesium oxide, for example, dissolves poorly and is absorbed less well than more soluble forms like Dimagnesium Malate. Calcium Citrate absorbs well with or without food.
• Where's the sugar? If sugar is near the top of the ingredient list, you're drinking a sports drink with minerals added — not an electrolyte product with a little flavor.
• Is there a proprietary blend? A proprietary blend lists ingredients under one combined weight, so you can't tell how much of each you're getting. Every amount should be printed on the supplement facts panel.

How Redi approaches it

Every Redi stick has all five electrolytes — sodium and chloride from Pink Himalayan Sea Salt, potassium and more chloride from Potassium Chloride, magnesium from Dimagnesium Malate, and calcium from Calcium Citrate. No added sugar, no proprietary blends, every amount on the panel.

Replenish is the caffeine-free formula for any time of day. Amplify is the same electrolyte base plus 350mg of caffeine for long days that need a lift — one stick per day, taken early. For more on that, see How Much Caffeine Is Too Much on a Long Shift?

Want the full breakdown of every ingredient? It's all on The Science page and in our glossary.

Quick answers

What are the five main electrolytes?

Sodium, potassium, magnesium, calcium, and chloride.

Does water have electrolytes?

Plain water has very little. Tap and mineral water contain small amounts of minerals, but not enough to replace what you lose over hours of heavy sweating.

Can you get electrolytes from food?

Yes, and on most days food covers it. Electrolyte drinks help most when you're losing more than you'd normally eat — long, hot, sweaty stretches.

Are electrolyte drinks just sports drinks?

Not necessarily. Many sports drinks lead with sugar for quick energy. An electrolyte product built for hydration should lead with the minerals — check the label.

Sources: NIH Office of Dietary Supplements, Magnesium Fact Sheet; NIH Office of Dietary Supplements, Calcium Fact Sheet; NIH Office of Dietary Supplements, Potassium Fact Sheet; NIOSH, Working in Heat. This article is general information, not medical advice. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.