What Should Runners Look for in an Electrolyte Supplement?

When it comes to optimizing performance and recovery, runners know that proper hydration is key. “Drinking water is good for you” is not groundbreaking news. Duh. But have you ever been super diligent about hydrating on a run, only to come down with cramping, dizziness, and an overwhelming sense of fatigue? If so, you might be missing a key factor: electrolyte supplements.

But electrolytes are basically just salt, right? And as we hear from health experts daily, Americans eat too much of it. So what’s the deal for runners?

What Even Are Electrolytes? 

Electrolyte is just a fancy word for salt and the other essential minerals like calcium and potassium that play vital roles in the body. They exist naturally in foods like bananas, avocados, spinach, and coconut water, and many of us add them to pretty much everything we eat. (“Pass the salt, please!”)

Electrolytes also play a key role in athletic performance, helping your body balance fluids inside and outside of its cells, regulating energy levels, assisting with muscle contractions, and managing neurotransmitters in your brain—keeping you alert and focused. If the average person is consuming enough of these foods along with a healthy amount of water, it might not be necessary for them to supplement with electrolyte powders and tablets. But runners require replenishing, as studies show they can lose anywhere between 500-2,000mg of sodium per liter of sweat depending on the intensity and longevity of their workouts, as well as their salt sweat rates and how much they sweat as a whole.

Do Runners Need Electrolytes?

You might be thinking: OK, another supplement. But I don’t need it…do I?

The short answer? If you run, then most likely.

When you exert yourself on a run, your body warms up, and you sweat. You might sweat a lot. That means you’re losing water and electrolytes. And if you don’t replenish both of those, you’ll end up dehydrated. Dehydration means you have less water in your blood plasma, which makes blood thicker. This makes it harder for the heart to pump oxygen to your muscles.

And it doesn’t take much for all this to happen. Studies have shown that, in an endurance event, even a 2 percent loss in body weight due to dehydration can impair athletic performance.

You might think you’re doing yourself a favor by chugging water on your run or during a race, but if you’re not balancing it with enough electrolytes, you could experience hyponatremia, a condition where you have too much water but not enough sodium in your blood. When you have an electrolyte imbalance, your muscles don’t receive proper signals to ready themselves for all the contracting and nerve impulses needed for running, so, as research proves, you wind up with cramps, fatigue, weakness, and overall poor performance. Hyponatremia is a serious issue, and while, in minor cases, you can bonk and DNF a race, at its worst, it can be fatal.

That’s why it’s vital to make sure you’re replenishing not only fluids, but also electrolytes to keep all systems firing, especially in high-mileage weeks, races, or during hot and sticky workouts. Electrolyte supplements can help your body replenish and retain fluid during runs, aid in moving fluid into your muscles while they work, and can even improve sleep—which, in turn, boosts recovery.

When Should I Take Electrolytes

There are a few different instances that determine when you should drink electrolytes. If you’re racing a marathon, you’ll want to start drinking them the day before so you’re hydrated when you start and better prepared to absorb fluids during the race. A NASA study calls this process preloading.

Research shows you should take in electrolytes and water around the 60-minute mark of your run, although if it’s an especially hot day or you’re prone to sweating a lot, you might want to consider starting earlier. Our experts say it’s important not to chug your electrolytes in one sitting, as you could risk upsetting your stomach. Instead, sip frequently throughout the rest of your run.

If you’ve had a particularly tough, hot, or long run, you’ll want to supplement with electrolytes afterwards, too. Your post-workout electrolytes can be more caloric now that you don’t have to worry about too much jostling around in your stomach. Sports drinks have both electrolytes and carbs to replenish what you’ve lost, but you can also have a banana or chocolate milk.

On rest days or days when you know your runs aren’t going to be longer than 60 minutes, it’s probably not necessary to supplement your water with electrolytes—especially if you incorporate a few of those foods we talked about earlier. If you’re properly replenishing during your run and after your run, your electrolytes should be balanced. It’s worth noting that this can be a case-by-case basis, depending on how intense your running regime is. If you’re an elite runner, for example, you might need daily electrolyte supplementation.

What Makes a Good Electrolyte Supplement?

Quality electrolyte supplements make drinking water easier and tastier—it’s a win-win. But they’re not all created equally, so how do you know which one is for you?

Different electrolyte supplements and sports drinks serve different ends. For instance, some are geared towards more everyday drinkability, containing moderate to small amounts of sugar and salt. If you’re on a run, you probably don’t want to use those, because—hello—we need all that sugar and salty goodness. Electrolyte mixes created for endurance athletes have to provide more to replace what’s lost in workouts and runs.

We asked running nutritionists what makes a good electrolyte supplement for runners, and they summarized with this: enough calories and electrolytes for your level of running and ingredients that won’t upset your stomach.

Does It Have What You Need?

Sara Cuff, a running nutritionist and founder of Eat 2 Run Sports Nutrition, suggests runners should try electrolyte drinks that start with at least 300mg of sodium per serving. Julie Shobe, an ultramarathon nutritionist, says, “When you are running, your primary needs are to replace overall sweat and sodium loss and keep your energy stable. Therefore, you need to consume fluid, sodium, carbs, and sugar. A beverage that is going to do that best is one that ideally has 20-60g of total carbohydrate per serving and 200-1000mg sodium per serving.”

Those ranges are pretty wide, but that’s the point. Shobe says the rehydration process is highly individualized: “Some runners might need to replace their sodium loss at 200mg per hour, while others need to place sodium at greater than 1000mg of sodium per hour.” Both Shobe and Cuff say that their recommendations are highly personalized based on the runner and variables like their history of sweating, endurance event of choice, and the temperature. If you want to know exactly how much salt you’re losing, and thus how much you need to replace, you can take a sweat test.

When you tally up all the requirements for the electrolytes best suited for your distance and effort, you might see some of the same nutrients in a sports drink like Gatorade or Powerade. While that may be true, most sports drinks contain more sugar than electrolyte supplements, and thus are better suited for mid-run. You can also find recovery mixes with carbs, electrolytes, and protein that you can use to replenish your stores after your workout. . Race aid stations will usually have some kind of sports drink available to grab, but as you don’t know exactly what or how much electrolytes you’re taking in from that paper cup (most aid station sports drinks are made in huge, often diluted batches prior), it’s better to come prepared with your own personalized electrolyte plan. (Salt pills can be a godsend in these situations, just make sure you dial in exactly how much salt you need so you don’t overdo it, either.)

Do The Ingredients Work For You?

Another key component of finding the right electrolyte supplement for you is to check that the ingredients won’t mess with your digestive system. Shobe suggests avoiding products with artificial sweeteners, as they usually provide fewer calories (because less sugar) and thus don’t help you replenish much of what you lost. So she suggests avoiding electrolyte supplements with artificial sweeteners or sugar alcohols like Stevia, monk fruit, Truvia, aspartame, sucralose, acesulfame K, and saccharin.

“Artificial sweeteners and sugar alcohols can cause GI discomfort for some, and sugar alcohols like xylitol can cause diarrhea,” she says. “Not a fun thing to have during a run!”

Cuff agrees with Shobe on the idea of avoiding most artificial sweeteners, adding that most food dyes also aren’t necessary.

“Personally, as a holistic sports nutritionist, I steer myself and my clients clear of artificial flavorings, sweeteners and colorings (there is enough information available that convinces me of the downsides of artificial ingredients, including gut issues and stress on other organs of the body) and instead opt for electrolyte drinks that are as natural as possible,” she says. “So food dye is one ingredient that isn’t needed and I definitely avoid. I also will absolutely avoid all artificial sweeteners. However, I’m okay (not enthusiastic, but okay!) with the natural non-calorie sweeteners stevia and monk fruit.”

Much like you should test out gels and chews to see which ones settle the best in your stomach, you should also experiment with a few different electrolyte supplements during your runs.

Mistakes You Can Make Taking Electrolytes

Going too natural

Coconut water can be a great source of electrolytes, but not all brands work for endurance athletes. Take 365 Whole Foods brand organic coconut water, which has 560mg of potassium, but only 40mg of calcium and 50mg of sodium. Other brands of coconut water have even less, some with zero salt at all.

“I can say to this day I’m astonished how many people (who are trying to eat as natural foods as possible, which I appreciate) think that coconut water is a good source of electrolytes to fuel with on the run,” Cuff says. “Coconut water [often] contains zero sodium! Of course, one could add some sea salt to coconut water, and that’s a pretty solid electrolyte drink—but might not be great for the gut.”

Not finding the right balance

Another common mistake is picking an electrolyte supplement that has too many or too few calories.

“A product with less than 20g of carbs per serving likely has some form of artificial sweetener, which makes the beverage taste sweet without providing any energy,” Shobe says. “But a product that has higher than 60g of carbs per serving might get thick in texture and be difficult to tolerate for long periods of time.”

Going overboard on sugar

Speaking of sugar, it’s another common snafu we run into with electrolyte powders. Because, as we know now thanks to research, glucose (sugar) can promote the transference of water and electrolytes into the bloodstream. For this to happen, a typical electrolyte drink would need to contain about 25g of glucose per liter of water, and be paired with potassium, sodium and magnesium for optimal rapid rehydration. If you’re taking in about 8 oz. of an electrolyte drink, you would need about 6g of sugar to start that process.

However, if you go overboard on the sugar, that can actually lead to a dehydrating effect and stomach issues. While this isn’t often a concern for Shobe’s ultrarunning clients or even Cuff’s marathon runners, it’s something to keep an eye on if you’re doing a less intense workout.

Taking daily electrolytes unnecessarily

“While certainly some companies advocate for using an electrolyte daily, I do not believe anyone needs to,” Cuff says, “[If you’re concerned about daily electrolyte intake] salt food to taste with sea salt. It doesn’t have to be complicated or expensive.”

She echoes our sentiments about there being a different kind of electrolyte powder for everyone—including the daily, casual sipper.

“There are definitely two different types of electrolytes: some are low-caloric with about 10 calories, containing anywhere from 100-1000mg of sodium per serving,” she says. “And the other are sports drinks which I typically recommend for athletes to use during long runs—these usually have 80-100 calories per serving (mostly from sugar) and 300-600mg of sodium.”

Consider choosing a “lower level” electrolyte drink if you’re not running a hard workout that day. Or, opt for something like coconut water.

Electrolytes for every runner and occasion:

For distances 5K to a marathon:

Skratch Sport Hydration

• Serving: 22g
• Calories: 80
• Carbs: 20g
• Sugars: 19g
• Sodium: 400mg

For distances longer than a marathon:

Tailwind Endurance Fuel

• Serving: 27g
• Calories: 100
• Carbs: 25g
• Sugars: 25g
• Sodium: 310mg

For daily, lighter runs:  

Nuun Sport Hydration

• Serving: 1 tablet (5g)
• Calories: 15
• Carbs: 4g
• Sugars: 1g
• Sodium: 300mg

For runners with high-sodium needs: 

LMNT Electrolyte Drink Mix

• Serving: 6g
• Calories: 10
• Carbs: 2g
• Sugars: 0g
• Sodium: 1000mg

For runners who value taste above all else:

Mortal Hydration 

• Servings: 13g
• Calories: 45
• Carbs: 10g
• Sugars: 8g
• Sodium: 450mg

For runners who want caffeine:

Gnarly Fuel20

• Servings: 29g
• Calories: 100
• Carbs: 25g
• Sugars: 25g
• Sodium: 250mg
• Caffeine: 30mg