Electrolytes for triathlon: what do you need?

Jan 16, 2019 5:38:52 PM
3 min read

What are required electrolytes for triathletes?

Triathlon nutrition can be quite confusing, especially when you are just starting out. Isotonic drinks, recovery shakes, amino acids,...

And what are those electrolytes experienced racers keep talking about? And which ones do you need for triathlon? Where to get them?

Let's have a brief look at electrolytes, and which ones you need for triathlon.

What are electrolytes?

According to Wikipedia, electrolytes are "substances that produce an electrically conducting solution when dissolved in a polar solvent, such as water". Electrolytes are minerals that have an electric charge, either positive or negative. In our bodies, they regulate several processes such as the flow of water in and out of cells and the sparking of nervous impulses.

In essence, electrolytes make sure the body's cells don't shrivel up or burst and that muscles, heart, lungs,... get the necessary signals to function properly .

It is obvious that these hydrating and signaling functions are very important for triathletes.

The main electrolytes are:

  • Sodium
  • Potassium
  • Chloride
  • Calcium
  • Magnesium

All these electrolytes get excreted in sweat (sodium most of all). Losing too much of them will impair performance and even cause health risks. Especially in conditions of high temperature and humidity, when sweat rates are the highest, athletes can excrete too many electrolytes to function at an optimal level. 

What do electrolytes do?

Let's start with the electrolyte that deserves most of our attention: sodium.

Sodium, also known as salt, is the electrolyte most abundantly present in sweat. We excrete it at an average rate of 850-1000 milligram per liter. That is why sweat tastes so salty, and that athletes sometimes have white marks on their black training gear.

Sodium receives a lot of attention. If you have read our blog on the perfect sports drink, you will know that it is extremely important to absorb water through the intestines and that it is necessary for glucose absorption.

Does it make sense to ingest it during longer training or races? Absolutely! Not only does it protect your health (dehydration can have very serious consequences), it also improves your performance.

In this study, it was shown that triathletes who properly replenished lost sodium levels during the race, finished a 70.3 Ironman (a half distance Ironman) on average 26 minutes faster than their counterparts!

However, sodium does not operate alone: it interacts with potassium to regulate hydration. Potassium is mainly found inside the cell whereas sodium is mainly found on the outside. Through a system called the "sodium - potassium pump", water and glucose get transported.

Chloride also works to keep the proper hydration balance in your cells and makes sure the pH of your body fluids is under control. It also regulates proper blood volume and pressure. It is naturally part of salt (sodium chloride) and potassium (potassium chloride).

Magnesium is a bit of a wonder mineral, as you can read in our blog on the subject. Trace amounts of magnesium also get lost in sweat, although not as much as sodium. It has about 300 functions in the body. What interests us most in this context, is that it is crucial for the production of ATP, your body's energy currency. As you give it your all and need a maximum production of ATP, magnesium will support you. This study also demonstrated that it lowers lactic acid levels in athletes.

Calcium is best known for its importance for teeth and bones, but it also regulates certain muscle functions such as contracting and relaxing. A little known fact is that if added in the right dosage, it can eliminate the negative effect on teeth enamel usually caused by sports drinks. We'll elaborate on that in a future blog.

How do I consume enough electrolytes?

Your main source of electrolytes should always be food: eating plenty of vegetables, fruits and wholesome foods is still the best way to top up on electrolytes during the day. Sodium can be found in salty dishes. Bananas and coconut water are famous for their high potassium content and dairy is full of calcium.

But what about during training or competition? Should you replace lost electrolytes?

Yes, you should. Especially in circumstances where you sweat a lot and in efforts lasting over 2 hours.

Ideally you replenish the electrolytes in the same ratio as they are lost: you sweat out way more sodium than magnesium, for instance.

On average, sweat contains:

Mineral mg/l
Sodium 460-1840
Chloride 710 - 2840
Potassium 160 - 390
Magnesium 0-36
Calcium 0-120


So your ideal sports drink should contain all these electrolytes in a similar ratio, with the exception of calcium: this should be 355 mg/l to neutralize tooth enamel decay.


Electrolytes are essential to health and performance, especially for triathletes due to the extended nature of their efforts.

Triathlon electrolyte replacement can be made very easy by using proper triathlon nutrition, such as Hiddit's Isotonic, offering all these electrolytes in the exact ratio. This takes the guesswork out of electrolytes, and let's you focus on smashing that race!

Want to give it a try? Visit our shop now!

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