The Short Version
Electrolytes are minerals that carry an electrical charge when dissolved in water. In the body, the main ones are sodium, potassium, chloride, magnesium, calcium, bicarbonate, and phosphate. They sit in your blood, sweat, and the fluid inside and outside your cells, and they're involved in just about every signal your nerves and muscles send.
When you sweat, you lose water and you lose some of these minerals - primarily sodium and chloride, with smaller amounts of potassium and magnesium. An electrolyte product is, very simply, a way of replacing that mix in a measured way.
What You're Actually Losing in Sweat
Sweat is mostly water, but it isn't pure water. The mineral concentration in sweat varies a lot between people - published research puts sweat sodium anywhere from roughly 200 mg/L to over 1,500 mg/L depending on the individual and the conditions. That's a big range, and it's why what works for one person can feel underdone or overdone for another.
The other minerals are present at much lower concentrations. Potassium is typically in the range of 100-250 mg/L of sweat; magnesium and calcium are lower still. So when an electrolyte drink talks about "the big three", the heavy lifting is sodium - see this breakdown.
What an Electrolyte Drink Is
At its simplest, an electrolyte drink is water with a measured dose of minerals added. Some products also include carbohydrate (sugar or maltodextrin) for energy; others are sugar-free and exist purely for the mineral component.
Format varies - powders to mix at home (e.g. Dr.Hydrate, Endura, Staminade), sachets you tip into a water bottle (Liquid I.V., LMNT), effervescent tablets (Nuun, Hydralyte, SiS), or ready-to-drink bottles (Gatorade, Powerade). The minerals are the constant. The format is convenience.
What an Electrolyte Drink Isn't
Electrolytes aren't a substitute for food, sleep, or training. They aren't an energy drink (no stimulants). They aren't a medicine - products on Australian shelves are usually classified as food or supplements rather than therapeutic goods, and the messaging on the panel reflects that.
If you're trying to work out whether you need one at all, the next post in this category - When Do You Actually Need Electrolytes? - walks through some realistic scenarios.
Want to Read the Label?
The number that matters most on the back of pack is sodium per serve. That's the mineral you've lost the most of in sweat, and it's also the one with the widest variation between products. Reading an Electrolyte Label walks through how to compare two panels honestly.
Sources
Authoritative references this article draws on. External links open in a new tab.
Frequently Asked
Do I need electrolytes if I'm just drinking water all day?
For most people in office or daily-life contexts, food covers electrolyte needs and water covers fluid. An electrolyte product earns its place when sweat losses are noticeably higher - heat, long training, or hot worksite days. See when you actually need electrolytes for a practical walk-through.
Are electrolytes the same as salts?
Effectively yes for the most common ones. Sodium chloride (table salt) is the headline electrolyte by quantity in sweat. Other electrolytes - potassium, magnesium, calcium, chloride, bicarbonate, phosphate - are all dissolved mineral compounds the body uses for various electrical and chemical roles.
How many electrolytes should be in a drink?
There is no single right answer - it depends on use case. A daily-hydration powder might sit around 200 mg sodium per serve; a heavy-sweat product might sit at 1,000 mg. Reading an electrolyte label walks through how to compare two products honestly.
Do electrolytes really help hydration?
Sodium and a small amount of glucose taken together help the small intestine absorb water faster than plain water alone (the sodium-glucose co-transport mechanism). For ordinary daily hydration this is a small benefit; after heavy sweat losses it is meaningful.
