Ingredient
Strong evidenceElectrolytes
Also known as: sodium, potassium, electrolyte powder
Sodium first — it is what actually makes a hydration product work.
What it is
Electrolytes are minerals that carry an electrical charge and govern fluid balance, nerve signals and muscle contractions. The main ones in hydration products are sodium, potassium and magnesium, with sodium doing most of the work.
How it works
When you sweat you lose fluid and a significant amount of sodium. Replacing that sodium is what lets your body hold onto water and maintain performance during long or hot training. Potassium and magnesium play supporting roles. A product without meaningful sodium is mostly flavour, no matter what the label promises.
Effective dose
For heavy or prolonged sweating, effective hydration products provide a substantial sodium dose, often 500 to 1000mg per serving, plus supporting potassium and magnesium. Everyday gym sessions need far less; match the dose to how much you actually sweat rather than over-salting routinely.
Safety and upper limit
Electrolyte products are safe for healthy people in normal use, but high-sodium formulas are not for everyone. Those with high blood pressure, kidney or heart conditions should be cautious with added sodium and seek medical advice. Plain water is fine for short, light sessions.
Where you find it
Hydration powders and tablets, intra-workout drinks and some pre-workouts.
Top Hydration picks
The highest-scoring products in the category where Electrolytes matters most.
Frequently asked
Which electrolyte matters most?
Sodium. Effective hydration products often provide 500 to 1000mg of sodium per serving, with potassium and magnesium in supporting roles.
Why are cheap electrolyte tablets less effective?
They usually contain only token amounts of sodium and lean on flavour and sugar, so they replace far less of what you lose in sweat.
Do I need electrolytes for every workout?
No. Short, light sessions are fine on water. Electrolytes earn their place during long, hot or heavy-sweat training.
Related guides
This page is educational and not medical advice. Doses are general guidance from the published research, not a personal prescription. Before starting any supplement that could affect a medical condition or interact with medication, speak to a qualified clinician.