Electrolytes for Runners: What You Need to Know

It can be difficult to know which information presented to us by the media that we should listen to. There are so many conflicting messages, and we hear more and more about conspiracies that make us question what we once thought was healthy.

How do you know what to listen to and what to ignore?

That is where we like to step in to help.

We want you to run as fast as you can, enjoy your running as much as you can, and become the best runner you can be. In this article, we’ll outline why maintaining electrolyte balance is important and outline a scientifically formulated plan to help you do it.

What do electrolytes have to do with running?

In previous articles, we’ve looked at why fueling is important in running long races like the marathon.  Taking in fuel in the form of sugar will allow you to get all the way to the finish line without hitting the wall.

But another fueling concern we haven’t addressed is the loss of electrolytes via sweat.

Electrolytes, as you might know from the marketing efforts of sports drink producers, are charged ions that play a multitude of essential roles in regulating your body, not just during exercise, but during your everyday life as well.

Here’s the deal:

The electrolytes sodium and potassium play a critical role in regulating your body’s water balance during exercise: the levels of these electrolytes allow your muscle cells (and every other cell in your body, for that matter) to retain the right amount of water.  But when we exercise, we lose electrolytes via sweating.  The sodium content of sweat is why it tastes so salty.

In a short race, like a 5k, electrolyte loss isn’t a major concern, even on a very hot day (although you do have a higher risk of heat stroke).  But in long races in the heat, especially if you aren’t acclimated to exercising in hot weather, electrolyte losses can impair performance.

If you are trying to rehydrate by drinking a lot of water, failing to consume electrolytes at the same time can upset the balance of electrolytes in your bloodstream.

In a worst-case scenario—drinking lots of water during a very long race in the heat, for example—this can even lead to a dangerous condition called hyponatremia, where blood sodium levels drop too low.

Therefore, keeping your electrolytes balanced is critical for both performance and health.

The benefits of maintaining electrolyte balance

Even in more mundane situations, when not racing in extreme heat, maintaining your electrolyte balance has its advantages.

A 2001 study by Sanders, Noakes, and Dennis found that cyclists who consumed a sports drink with sodium in it during a 4.5 hour ride produced much less urine than those who consumed an equivalent volume of salt-free sports drink.

They concluded that this was because the cyclists did not need to excrete as much water to balance out the sodium concentration inside their bodies.

This bodes well for marathoners—after all, who wants to have to take a bathroom break during a race?

It seems strange that the “saltiness” of a fluid influences how much urine your body will produce, but when the fluid you’re drinking (the sports drink) is closer in electrolyte concentration to the fluid you’re losing (sweat), your body can more or less replace the sweat one to one instead of having to add in electrolytes that are already in your body, resulting in lower overall sodium levels in your blood.

According to Tim Noakes, a physiology researcher and medical doctor in Cape Town, South Africa, sodium is the only electrolyte of importance to endurance athletes during exercise.

Although potassium and magnesium ions are lost as well, their concentration in sweat is so low that depletion of these electrolytes is not a problem.

The best way to replace electrolytes

So, what’s the best way to replace the electrolytes you’re losing?

Old-school salt tablets are certainly an option, and you could also look into EnduroPacks, who have created an electrolyte spray with all the essential electrolytes no matter what you are doing. Thirdly, you can always fall back on the almost unlimited sports drinks lining the shelves.

While Noakes writes that he would prefer modern sports drinks to have a somewhat higher sodium content, he admits that the electrolyte content of popular drinks like Gatorade and Powerade are at least close to being adequate for marathoners.

While sports drinks are easy when racing, when you’re replenishing electrolytes throughout the day, you don’t want to be consuming high amounts of simple and artificial sugars.

That is why we like EnduroPacks Electrolyte Spray as you can add it to any drink of your choice, and it contains zero sugar and zero calories.

You could also look into Hammer Fizz, Nuun, and Nathan Catalyst as flavored alternatives to put in your drinks.

When and how much to consume

When it comes to when and how much to consume electrolytes, you can follow basic guidelines for hydration during exercise.

• Hydrating during a workout or a race usually isn’t necessary unless it will last longer than an hour.

• In longer events, drinking “ad libitum“—i.e., to thirst—is the recommended method.  For most people, this ends up being between 14 and 20 fluid ounces per hour of exercise.  In marathons, you’ll also have to take carbohydrate fueling into account, as depending on your fueling needs, this amount of fluid intake may or may not provide you with enough sugar to prevent hitting the wall.

• As with almost everything in running, when it comes to losing and replenishing electrolytes every runner is different. Some runners are “salty sweaters” and some people sweat very little. Luckily, we’ve created a very handy sweat loss calculator for runners that will help tell you exactly how much sweat you lost and give you a much more accurate estimation of how much water and electrolytes you need to replace.

Conclusion

Finally, it’s important to note that your electrolyte loss (and fluid loss in general) will be greater in the heat.  Fortunately, this is compensated for by an increase in thirst, so drinking to thirst in workouts and races that last longer than one hour should keep you on the right track, as long as you’re consuming sodium as well.