Replenishing electrolytes after exercise: what do you really need?

What are electrolytes and why are they important after exercise? 

Electrolytes are minerals with an electrical charge, such as sodium, potassium, magnesium, calcium and chloride. These little heroes play a key role in all sorts of bodily processes: 

• They regulate your fluid balance, so your cells and organs continue to function properly
• They are important for proper muscle function
• They contribute to the normal functioning of the nervous system

In short: when you exercise and sweat, you lose fluid and electrolytes. Want to know more? Read everything about electrolytes here. 

How do you lose electrolytes when you sweat? 

When you sweat, you mainly lose sodium. But potassium, magnesium and calcium are also lost through your pores. Exactly how much you lose depends on:

• The intensity and duration of your training
• The ambient temperature (heat = more sweat = greater loss)
• Your unique sweat profile – yes, really, every body sweats differently! 

On average, you lose around 1 litre of sweat per hour of intense exercise, which equates to roughly 1,000 mg of sodium. That’s quite a lot!

Replenishing electrolytes after exercise: what do you really need? 

The solution? Restore balance. Here’s how: 

• After exercise, drink 1.5 times as much fluid as you’ve lost. Lost 1 kg? Then drink 1.5 litres of water.
• Add electrolytes to your recovery routine. Think sodium (salt), potassium (banana), magnesium (almonds) and calcium (green vegetables or dairy). Or choose an electrolyte drink: everything in one. 

💡 Tip: You really don’t need to reach for a sports drink straight away. Often, you can get a long way with food alone. 

Natural dietary sources of electrolytes 

Did you know you can get plenty of electrolytes simply from your food? These ingredients are smart to include in your post-workout meal: 

With a well-rounded meal, you don’t just restore your energy—you also bring your electrolytes back up to scratch. 

Electrolyte powders, drinks and sports drinks: what really works? 

Not every sports drink is a healthy choice. Many commercial drinks contain a lot of sugar—sometimes as much as 30 grams per bottle. And you certainly don’t always need those extra sugars. 

When is an electrolyte drink actually useful? 

• If you train intensely for longer than 60 minutes
• If you exercise in warm conditions
• If you lose a lot of sweat

In that case, go for an isotonic drink: with 6–8% carbohydrates and 500–700 mg sodium per litre. Or choose an electrolyte tablet with no added sugars that you dissolve in your water. 

Electrolyte supplements: useful or unnecessary? 

For most people, a supplement isn’t strictly necessary. But in some cases it can be helpful: 

• Endurance athletes (think: marathon, triathlon)
• Athletes training in hot, humid conditions

A good electrolyte supplement contains sodium, potassium and magnesium—ideally in responsible dosages, without unnecessary additives.  

Tips to restore your electrolyte balance quickly 

Here’s how to bring your body back into balance after exercise: 

✅ Weigh yourself before and after training to determine how much fluid you’ve lost. 

 ✅ Drink enough, but not too much in one go. 

 ✅ Eat a recovery meal with salt and potassium-rich foods. 

 ✅ Choose a natural electrolyte drink or supplement if you train intensely. 

 ✅ Keep an eye on your urine colour: pale yellow = great, dark yellow = drink more. 

And most importantly: listen to your body. If you’re thirsty, it’s important to top up your fluid balance—and during prolonged exertion, your minerals too.

Good to know 

Electrolytes are more than a marketing term on a sports drink bottle. They play an important role in recovery after exercise. Fortunately, you don’t have to be a professional athlete to pay attention to them. With a bit of awareness—and a banana in your gym bag—you’ll already be well on your way. 

Want to know more about electrolytes or which supplements match your sports goals? Feel free to pop into the shop. Our health coaches are ready to help.

Sources 

• Jeukendrup, A. E., & Gleeson, M. (2019). Sport Nutrition: An Introduction to Energy Production and Performance (3e ed.). Human Kinetics.
• Sawka, M. N., Burke, L. M., Eichner, E. R., Maughan, R. J., Montain, S. J., & Stachenfeld, N. S. (2007). American College of Sports Medicine position stand: Exercise and fluid replacement. Medicine and Science in Sports and Exercise, 39(2), 377–390. https://doi.org/10.1249/mss.0b013e31802ca597
• Maughan, R. J., & Shirreffs, S. M. (2008). Development of individual hydration strategies for athletes. International Journal of Sport Nutrition and Exercise Metabolism, 18(5), 457–472. https://doi.org/10.1123/ijsnem.18.5.457
• Shirreffs, S. M., & Sawka, M. N. (2011). Fluid and electrolyte needs for training, competition, and recovery. Journal of Sports Sciences, 29(S1), S39–S46. https://doi.org/10.1080/02640414.2011.614269
• EFSA Panel on Dietetic Products, Nutrition and Allergies. (2011). Scientific opinion on the substantiation of health claims related to magnesium and electrolyte balance. EFSA Journal, 9(4), 2042. https://doi.org/10.2903/j.efsa.2011.2042
• Voedingscentrum. (n.d.). Fluids and sport. Accessed 1 April 2025, from https://www.voedingscentrum.nl
• Gatorade Sports Science Institute (GSSI). (2020). Hydration and Electrolyte Balance in Athletes. Accessed from https://www.gssiweb.org