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Electrolytes are everywhere right now: in sports drinks, effervescent tablets, powders and in the bottle of almost every runner. But what are electrolytes, what do they actually do in your body and do you really need them when you exercise? The honest answer: sometimes, but often water is enough. In this article you’ll find out when electrolytes make a difference, where you can get them and how to use them smartly around your training.
Electrolytes at a Glance
What are electrolytes?
Electrolytes are minerals that dissolve in water to form electrically charged particles. You find them in your blood, inside your cells and in the fluid around them. Your body needs that charge to pass signals between your nerves and muscles and to keep fluid in the right place.
The main electrolytes are sodium, potassium, magnesium, calcium, chloride and phosphate. For active people, three of them stand out:
The mineral you lose most through sweat. Sodium plays a central role in your body’s fluid balance.
Potassium contributes to normal muscle function and to normal functioning of the nervous system.
Magnesium contributes to electrolyte balance and to normal muscle function.
Want to know more about magnesium? Read about the benefits of magnesium, or check our guide to the 8 most important minerals to see if you’re getting enough.
What do electrolytes do in your body?
Electrolytes work as a team. Together they control how much fluid sits in and around your cells, and they make sure the signals from your nerves reach your muscles. Here’s what they do:
- Fluid balance: sodium and potassium together decide where the water in your body goes.
- Muscle function: potassium, calcium and magnesium contribute to normal muscle function.
- Nervous system: potassium contributes to normal functioning of the nervous system and calcium to normal neurotransmission.
- Energy: magnesium contributes to the reduction of tiredness and fatigue and to normal energy-yielding metabolism.
Good to know: electrolytes don’t provide energy themselves. For fuel during long sessions you need carbohydrates, for example from energy gels like our Energy Gel.
What foods and drinks have electrolytes?
You don’t have to look far: you get most electrolytes simply from your food. With a varied diet, you usually cover your needs on a normal day without any trouble.
| Electrolyte | Where to find it |
|---|---|
| Sodium | Salt, bread, cheese, stock, cured meats |
| Potassium | Bananas, potatoes, beans and lentils, vegetables, dried fruit |
| Magnesium | Nuts, seeds, wholegrains, oats, dark chocolate |
| Calcium | Milk, yoghurt, cheese, leafy greens |
| Chloride | Salt, tomatoes, olives |
As for drinks, milk, coconut water and sports or electrolyte drinks all contain electrolytes. Want to know which foods support you through long training sessions? Read our guide to the best foods for endurance athletes.
Do you need electrolytes for exercise, or is water enough?
This is the nuance that often gets lost. For most workouts of an hour or less, water is all you need to stay well hydrated. Extra electrolytes start to matter when you train for a long time, at high intensity or in the heat, and sweat a lot as a result. Sports science guidelines recommend replacing fluid and sodium during prolonged exercise, and tailoring your approach to how much you sweat.
| Situation | What works best? |
|---|---|
| Short session | Strength training or a session under an hour: water is usually enough. |
| Endurance session | An hour or more: water with electrolytes, plus carbohydrates for long sessions. |
| Heat or heavy sweating | White salt marks on your top? Electrolytes are worth it, before and after training. |
| Race day | Marathon or long bike ride: plan fluid, sodium and carbs in advance and test them in training. See also what to eat before a half marathon or marathon. |
| Rest day | Water and a varied diet. |
Training for a long distance? Our complete guide to endurance training shows how hydration fits into your overall plan.
When to take electrolytes: before, during or after exercise
All three can work. It depends on your session.
Before exercise
Useful when you have a long or hot session ahead. A glass of water with electrolytes in the hour before you start helps you begin well hydrated.
During exercise
Mainly for sessions longer than about an hour. Take small sips regularly rather than drinking everything at once. On long sessions, combine them with carbohydrates, for example from our gels.
After exercise
After a sweaty workout, you help your body top up its fluid and minerals. A meal with a little salt and a glass of water often does the job. If you’ve sweated a lot, an electrolyte drink is a convenient option.
Electrolytes for runners
For runners, electrolytes mostly come into play on long runs, half marathons and marathons. Always test your drink in training, never for the first time on race day. Just getting started? Have a look at the most common mistakes beginner runners make.
Low electrolyte symptoms
A real deficiency isn’t common in healthy people. It can happen after long, hard exercise with heavy sweat loss, or when you’re ill with vomiting or diarrhoea. Signs to look out for:
- Tiredness and feeling weak
- Headache or dizziness
- Nausea
- Muscle weakness
If symptoms don’t go away, or you feel very unwell, speak to your GP.
Note: drinking a lot of water without replacing sodium can also cause problems during very long events. That’s why it’s smart not to drink plain water only during marathons and ultras.
How to make a homemade electrolyte drink
You can easily make your own electrolyte drink at home. A simple base:
- 500ml water
- A small pinch of salt, for sodium
- A splash of orange or lemon juice, for flavour and a little potassium
- A teaspoon of honey, if you also want some carbs for a long session
Prefer a sugar-free version? Simply leave out the honey and juice. Want it closer to an isotonic sports drink? Keep them in, so you get carbohydrates alongside your electrolytes.
The downside of DIY is the dose: you never know exactly what’s in your bottle. A ready-made product like Body&Fit Electrolytes or our Isotonic Electrolytes Drink is easier and more consistent, especially on the go. With Body&Fit Electrolytes you know exactly what you’re getting: 300mg potassium, 200mg sodium, 120mg calcium and 56mg magnesium per sachet.
What are the best electrolytes?
The best electrolytes are the ones that suit your training and that you’ll actually take with you. A few options:
- Powder in sachets: easy to dose and handy in your gym bag.
- Effervescent tablets: compact, but often lower in dose.
- Isotonic sports drinks: provide carbohydrates as well as electrolytes, like our Isotonic Electrolytes Drink. Great for long sessions, less necessary for a short workout.
- Energy drinks with electrolytes: Fit Energy Drink is sugar-free with natural caffeine and electrolytes. Find out more in our Fit Energy guide.
- Amino acids with electrolytes: Perfection Amino combines all 9 essential amino acids with the electrolytes sodium and potassium, with no added sugar.
- With or without carbs: without for hydration, with for extra fuel during long sessions.
Looking for a practical option? Body&Fit Electrolytes contains four electrolytes in one sachet: potassium, sodium, calcium and magnesium, for just 8 kcal per serving. With 300mg per sachet, potassium deliberately takes the lead. Easy to carry in your gym bag and straight into your bottle. You can also browse our full electrolytes range. Potassium, magnesium and calcium contribute to normal muscle function, and magnesium also contributes to electrolyte balance. Want to know which other supplements suit long training sessions? Read our guide to supplements for endurance athletes. Or browse our full performance range.
FAQ: electrolytes
Can you drink electrolyte water every day?
For healthy people, an electrolyte drink on a training day is generally fine. On days without exercise or much sweating you usually don’t need one: water and normal food are enough. If you have a kidney or heart condition, or you’re watching your salt intake, check with your GP first.
Should you take electrolytes daily?
Most people don’t need to. A varied diet already provides plenty of electrolytes, and most adults in the UK eat more salt than recommended. Save them for days when you train long, hard or in the heat.
Do electrolytes give you energy?
No, electrolytes contain no calories. They do help your body keep fluid and minerals in balance. For energy during exercise you need carbohydrates.
How many electrolytes do you need per day?
There’s no single amount of "electrolytes per day", as each mineral has its own recommended intake. With a varied diet you usually get enough. For salt there’s actually an upper limit: the NHS advises adults to have no more than 6g of salt a day. Extra sodium only makes sense when you lose a lot through sweat.
What are natural electrolytes?
This usually means foods that naturally contain electrolytes, like bananas, coconut water, dairy, nuts and a pinch of salt in your meals. Coconut water is high in potassium but low in sodium, so after heavy sweating it’s less complete than people often think.
Can you have too many electrolytes?
Used as directed, it’s rarely a problem for healthy people. Don’t take more than it says on the pack (for Body&Fit Electrolytes, that’s one to three sachets a day, depending on how much you sweat), and don’t combine several high-salt products if you’re not sweating much.
Got more questions about electrolytes? Follow us on Instagram, or read our article on how to drink more water every day for more hydration tips.
