Many runners spend a lot of time thinking about pace, mileage and training. But one area that’s often overlooked is hydration—and more specifically, electrolytes.
Water is essential for performance, but long-distance runners must also pay attention to electrolytes, especially sodium. Electrolytes play a critical role in helping the body perform, recover and avoid fatigue.
In a recent conversation with fellow sports nutritionist Leah, we broke down the science behind electrolytes and what runners really need to know about hydration. The takeaway? Many runners either underestimate their electrolyte needs or assume they need much more than they actually do.
Let’s look at what electrolytes are, why they matter, and how runners can follow their hydration strategy.
What are electrolytes?
Electrolytes are metals in the body that carry an electrical charge. They help regulate many key processes important to athletic performance, including muscle contraction, fluid balance, and nerve signaling.
There are several different electrolytes, including sodium, potassium, magnesium, and calcium. Sodium plays the biggest role in a runner’s performance because we lose so much through sweat. Every time you go for a run and sweat, even if it’s not particularly hot outside, you lose sodium along with fluids.
If these losses are not replaced, you will feel tired, have headaches, cramp or feel exhausted later in the day.
When do runners really need electrolytes?
It’s true that you don’t always need electrolytes on every run. For many runners, a useful rule of thumb is the 60-minute guideline.
If your run is longer than about 60 minutes, incorporate electrolytes into your fueling routine. During longer workouts, you sweat more, lose more sodium, and rely on hydration to maintain performance.
A general starting recommendation for endurance athletes is to consume 400-600 milligrams of sodium in 12-16 fluid ounces per hour of vigorous activity.
However, this number is not the same for everyone. Some runners lose more sodium than others, depending on their sweat rate and individual physiology.
Signs you may be losing more electrolytes than average
Not all runners sweat the same amount and not all sweat has the same concentration of sodium.
Some runners are ‘salty sweaters,“ people who have white salt marks on their clothes, hat or skin after running.
Other signs that you may need more electrolytes include:
- Frequent muscle cramps during long runs
- You feel unusually tired late in your workouts
- Headaches after exercise
- Heavy sweating even on shorter runs
If you notice these signs, increasing your sodium intake during exercise can help improve how you feel both during and after exercise.
Sports drinks vs. electrolyte powder
Another common point of confusion is the difference between traditional sports drinks and products containing electrolytes and when these products should be used.
Sports drinks were designed specifically for endurance athletes. They usually contain three main elements:
- Liquid
- 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 be helpful, especially if you combine them with another source of carbohydrates such as 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 nutrition source.
The myth of potassium
You’ve probably heard advice like “eat a banana” to avoid cramping during exercise. Many runners believe that low potassium is the culprit behind their muscle cramps. While potassium is indeed an electrolyte, it is usually not the primary factor behind exercise-related cramps.
The main electrolyte lost in sweat is sodium, which is why sodium replacement is often more important for runners. Muscle cramps often occur from loss of sodium, not potassium.
Another factor that can contribute to cramps is a low carbohydrate intake. If the muscles do not have enough fuel available, fatigue and cramps are more likely. This is especially common during long or intense runs.
A common hydration mistake runners make
A mistake many runners make is starting their training already dehydrated. This is especially common for early morning runners who wake up, grab a quick snack and head straight out the door.
Even if the run itself only lasts 30-40 minutes, starting your workout in a dehydrated state can lead to symptoms later in the day, such as 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 your workout. 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 their electrolyte intake.
It is certainly possible to get sodium from foods such as:
- Cookies
- Pickles or pickle juice
- cottage cheese
- Saltine crackers
These options can work well post-workout, 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 fluids without requiring large amounts of food during exercise.
Hydration is more personalized than you think
Perhaps the most important takeaway is that hydration strategies are not one-size-fits-all.
Sweat rates, sodium losses, training intensity, and environmental conditions can all affect how much fluid and sodium a runner needs.
Some runners may feel great on minimal electrolyte intake, while others benefit from a more structured hydration strategy.
The key is to pay attention to how your body responds and experiment during training, not on race day.
Need help dialing in your running nutrition?
Hydration and electrolyte strategies are only one part of the bigger nutrition picture for runners.
Within Better fuelmy training plan for plant-based runners, we dive deeper into how to fuel before, during and after workouts so you can train harder and recover faster.
