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 mini-heroes play a key role in various bodily processes: 

• They regulate your fluid balance, ensuring your cells and organs function properly
• They ensure proper muscle contraction, reducing the risk of cramps or twitching muscles
• They support the conduction of nerve impulses, which is important for coordination and focus

In short: when you exercise and sweat, you lose fluids and electrolytes. And then your body becomes imbalanced. Want to know more? Read all about electrolytes here. 

How do you lose electrolytes when you sweat? 

When you sweat, you primarily lose sodium. But potassium, magnesium, and calcium also escape through your pores. How much you lose exactly depends on:

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

On average, you lose about 1 litre of sweat per hour of intense exercise, which equates to approximately 1,000 mg of sodium. That's quite a lot! And you notice it: cramps, dizziness, or fatigue can all be signs of an imbalance. 

Lack of electrolytes: symptoms and consequences for athletes 

If you don't replenish electrolytes in time, your system becomes unbalanced. The symptoms can be mild, but also quite annoying: 

• Muscle cramps or twitching limbs
• Fatigue and reduced focus
• Dizziness, headaches, or even nausea 

Especially if you exercise for a long time or train in the heat, these complaints can significantly undermine your performance. 

Replenishing electrolytes after exercise: what do you really need? 

The solution? Restore balance. And here's how you do it: 

• Drink 1.5 times the amount of fluid you've lost after exercising. Have you lost 1 kg? Then drink 1.5 litres of water.
• Add electrolytes to your recovery routine. Think of sodium (salt), potassium (banana), magnesium (almonds) and calcium (green vegetables or dairy). Or opt for an electrolyte drink: everything in one. 

💡 Tip: You really don't have to grab a sports drink immediately. Often, food will suffice. 

Natural sources of electrolytes in food 

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

With a well-rounded meal, you not only restore your energy but also replenish your electrolytes. 

Electrolyte drinks and sports drinks: what really works? 

Not every sports drink is a healthy choice. Many commercial drinks contain a lot of sugar – sometimes up to 30 grams per bottle. And you don't always need those extra sugars. 

When is an electrolyte drink useful? 

• If you train intensively for more than 60 minutes
• If you exercise in warm conditions
• With a lot of sweat loss or cramp susceptibility

Then go for an isotonic drink: with 6-8% carbohydrates and 500–700 mg sodium per litre. Or choose an electrolyte tablet without added sugars that you dissolve in your water. 

Electrolyte supplements: useful or unnecessary? 

For most people, a supplement is not necessarily needed. But in some cases, it can be beneficial: 

• Endurance athletes (think: marathon, triathlon)
• Athletes in hot, humid conditions
• People with an increased risk of dehydration, such as with diarrhoea or excessive sweating 

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

Tips to quickly restore your electrolyte balance 

This is how you bring your body back into balance after exercise: 

✅ Weigh yourself before and after your workout to determine how much fluid you've lost. 

 ✅ Drink enough, but not too much at once. 

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

 ✅ Opt for a natural electrolyte drink or supplement if you train intensively. 

 ✅ Pay attention to the colour of your urine: light yellow = great, dark yellow = drink more. 

And most importantly: listen to your body. Are you thirsty? Then you need fluids and electrolytes. 

Good to know 

Electrolytes are more than just a marketing term on a sports drink bottle. They are essential for healthy recovery and optimal performance. 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 sports bag – you’ll go a long way. 

Want to know more about electrolytes or which supplements suit your sporting goals? Feel free to visit the store. Our health coaches are ready to assist you.

Sources 

• Jeukendrup, A. E., & Gleeson, M. (2019). Sport Nutrition: An Introduction to Energy Production and Performance (3rd 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.). Vocht en sport. Accessed on 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