Many runners spend a lot of time thinking about pace, mileage, and workouts. But one area that often gets overlooked is hydration—and more specifically, electrolytes.
Water is essential for performance, but long-distance runners also need to pay attention to electrolytes, specifically sodium. Electrolytes play a critical role in helping the body perform, recover, and avoid fatigue.
In a recent conversation with fellow sports dietitian Leah, we broke down the science behind electrolytes and what runners actually need to know about hydration. The takeaway? Many runners either underestimate their electrolyte needs or assume they need far more than they actually do.
Let’s walk through what electrolytes are, why they matter, and how runners can dial in their hydration strategy.
What Are Electrolytes?
Electrolytes are minerals in the body that carry an electrical charge. They help regulate several key processes that matter for athletic performance, including muscle contraction, fluid balance, and nerve signaling.
There are several different electrolytes, including sodium, potassium, magnesium and calcium. Sodium plays the largest role in a runner’s performance because we lose a lot of it through sweat. Every time you go out for a run and sweat, even if it’s not particularly hot outside, you’re losing sodium along with fluid.
If those losses aren’t replaced, you will feel fatigued, have headaches, experience cramping, or feel depleted later in the day.
When Do Runners Actually Need Electrolytes?
It’s true that you don’t always need electrolytes on every run. For many runners, a helpful rule of thumb is the 60-minute guideline.
If your run lasts longer than about 60 minutes, incorporate electrolytes into your fueling routine. During longer workouts, you’re sweating more, losing more sodium, and relying on hydration to maintain performance.
A general starting recommendation for endurance athletes is to consume 400–600 milligrams of sodium in 12-16 ounces of fluid per hour of intense activity.
However, this number isn’t the same for everyone. Some runners lose more sodium than others, depending on their sweat rate and individual physiology.
Signs You Might Be Losing More Electrolytes Than Average
Not all runners sweat the same amount, and not all sweat contains the same concentration of sodium.
Some runners are “salty sweaters,” people who have white salt marks on their clothes, hat, or skin after a run.
Other signs that you might need more electrolytes include:
- Frequent muscle cramping during long runs
- Feeling unusually fatigued late in workouts
- Headaches after exercise
- Heavy sweating even during shorter runs
If you notice these signs, increasing sodium intake during training may help improve how you feel both during and after exercise.
Sports Drinks vs. Electrolyte Powders
Another common point of confusion is the difference between traditional sports drinks and electrolyte-only products, and when to use these products.
Sports drinks were actually designed specifically for endurance athletes. They typically contain three key components:
- Fluid
- Sodium (electrolytes)
- Carbohydrates
The reason for this combination is that carbohydrates help provide energy, while sodium helps the body absorb fluids more efficiently. Together, they support hydration and performance during longer workouts.
Electrolyte powders or tablets, on the other hand, often contain sodium without carbohydrates. These can still be useful, particularly if you’re pairing them with another source of carbohydrates, like sports chews, gels, or real food. Or if you live in a very hot or humid climate, electrolyte tablets may help you stay hydrated for shorter distances.
Long-distance runners end up using a combination approach, getting sodium and carbohydrates from sports drinks and carbohydrates from another fueling source.
The Potassium Myth
You’ve probably heard advice like “eat a banana” to prevent cramping during exercise. Many runners think low potassium is the culprit behind their muscle cramps. While potassium is indeed an electrolyte, it’s usually not the primary factor behind exercise-related cramps.
The main electrolyte lost in sweat is sodium, which is why replacing sodium is often more important for runners. Muscle cramps often occur from sodium loss, not potassium.
Another factor that can contribute to cramping is low carbohydrate intake. If muscles don’t have enough available fuel, fatigue and cramping are more likely. This is especially common during long or intense runs.
A Common Hydration Mistake Runners Make
One mistake many runners make is starting their workout already dehydrated. This is especially common for early morning runners who wake up, eat a quick snack, and head straight out the door.
Even if the run itself is only 30–40 minutes long, beginning the workout in a dehydrated state can lead to symptoms later in the day like headaches, fatigue, or sluggishness.
A simple solution is to focus on hydration throughout the day, not just during workouts. Drinking water regularly and paying attention to hydration before exercise can make a big difference in how you feel during training. If you exercise in the morning, bring a water bottle with you and sip throughout your workout.
Can You Get Electrolytes From Food?
Some runners prefer to rely on food rather than sports nutrition products for electrolyte intake.
It’s certainly possible to get sodium from foods such as:
- Pretzels
- Pickles or pickle juice
- Cottage cheese
- Salted crackers
These options can work well after workouts, especially as part of a recovery snack that also includes protein and carbohydrates.
However, for longer endurance sessions—especially workouts lasting more than two hours—electrolyte drinks or supplements are more practical. They provide a concentrated source of sodium and fluid without requiring large amounts of food during exercise.
Hydration Is More Individual Than You Think
Perhaps the most important takeaway is that hydration strategies aren’t one-size-fits-all.
Sweat rates, sodium losses, workout intensity, and environmental conditions can all influence how much fluid and sodium a runner needs.
Some runners may feel great with minimal electrolyte intake, while others benefit from a more structured hydration strategy.
The key is paying attention to how your body responds and experimenting during training, not on race day.
Want Help Dialing in Your Running Nutrition?
Hydration and electrolyte strategies are just one part of the bigger fueling picture for runners.
Inside Fuel Better, my coaching program for plant-based runners, we dive deeper into how to fuel before, during, and after workouts so you can train stronger and recover faster.
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