In part one we looked at what electrolytes are and why they are so important to the body. Here in Part 2, we look at what happens to electrolytes as you exercise, why electrolytes are important and what you can do to optimise performance before, during and after a workout.

The main reason why electrolytes are lost during exercise is via the water lost through sweating. As a rough guide, you tend to lose about one litre of water per hour of exercise.

If you’ve have ever tasted sweat, you will notice that it does taste quite salty. This is because one of the main electrolytes that you lose in sweat is sodium, which is half of the molecule that makes up salt (salt is made from sodium and chloride).


A couple of other electrolytes are lost through sweat, magnesium and potassium, but in much lesser quantities.

Before your workout

Stay well hydrated. It is really important to stay well hydrated before exercise; the last thing you want to do is go into exercise being dehydrated. It is also possible, however, to come into exercise being over-hydrated, but you would need to drink a heck of a lot of water for this to happen.

More commonly though, many novices make the mistake of drinking too much water in one go pre-workout, which leads to general discomfort because of the sloshing of liquid in the stomach. It is better to drink little and often prior to an event or workout.

During your workout

Ultimately if your workout does not last more than an hour, there is no need to replace electrolytes as your exercise. It is important to keep water levels topped up though; generally 150-250ml per 15 minutes is sufficient.

If your workout lasts for more than one hour, it is worth thinking about replacing electrolytes as well as water.

There are loads of sports drinks on the market that advertise themselves as being rich in electrolytes, yet there is no proof out there that these drinks improve performance when exercising for less than an hour.

On the flip side, there is lots of evidence to say that they help when the duration of exercise exceeds one hour.

The main aim during exercise is to replace lost sodium through sweat, and there are two main types of sports drinks that will do this. One other thing that most sports drinks do is provide the body with a large amount of sugar, which gives an almost instant energy boost.

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After your workout

Even if you have hydrated and replaced electrolytes perfectly during your workout, it is still likely that you will be (even slightly) dehydrated and low on electrolytes.

It is important to replace these electrolytes as soon as possible after your workout so that the body can start to recover and repair itself optimally. There are a lot of drinks out there that provide this; they are usually advertised in some form or another as ‘recovery drinks’, however one thing to think about is the sugar content of these drinks.

Recovery drinks tend to have a very high amount of sugar in them, which is a good thing, unless you are particularly reactive to sugar. It is important to experiment with different types to see which ones work for you and which ones don’t.

There are three types of sports drinks

These are the main types of drink that you can get, and they all have different benefits and effects:

Hypotonic: These drinks have little to no electrolyte content and have very little sugar. Water is an example.

Isotonic: These drinks have a salt content that is similar to the salt content of the blood stream, usually a large amount of sugar and is probably the best type of drink to have during exercise.

Hypertonic: These drinks have a higher salt content than the salt content of the blood stream, usually have a very high amount of sugar, and are probably the best types of drink to have after exercise.

The most important thing is to remember is to stay well hydrated during any workout (150-20ml fluid per 15 minutes as a guide), and if your workout exceeds an hour, to replace electrolytes during your workout with an isotonic drink.

After workout is it important to replace lot fluids and electrolytes as soon as possible so your body can recover and recover optimally.

One thing to do if you have the time is to experiment with different drinks that have slightly different salt and sugar contents, as everybody is different and no one drink/time to drink is perfect for everybody.

One thing to not do is go with something you don’t know during a really important workout or race!

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Pollyanna Hale Health and Lifestyle coaches
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Mel, 32y Location: London, United Kingdom Working with Pollyanna changed everything. I lost 13kg, got toned and have more energy than ever! Get same results!


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