What Are Electrolytes and Why Do We Need Them?

This science-backed info will change how you think about sports drinks.

We all have that one friend who sprints home after a jog or sweaty yoga session to “replenish their electrolytes.” If you’ve ever been left behind in the locker room wondering what that even means, you’ve come to the right place. Most people know we need electrolytes, and that they’re linked to hydration and basic human function. Many of us also associate electrolytes with extreme forms of exercise, hot weather, and Gatorade.

But do we really need to replenish our electrolytes after every workout? It's true that we do need to consume more electrolytes (like Gatorade) after excessive sweating. But this isn't always the case. To learn more, we asked a registered dietitian and a physician to explain when we do and don't need to consume electrolyte drinks to rehydrate—along with some other helpful facts about these vital particles.

What Are Electrolytes?

“Electrolytes are particles that have a positive or negative electrical charge,” explains Jonathan Waitman, MD, medical director for specialized nutrition support at New York Presbyterian Hospital, Weill-Cornell Medical Center, and medical expert at the Institute of Culinary Education. “In the human body, electrolytes refer to essential minerals like sodium, potassium, magnesium, phosphorus, and calcium.”

According to Abbie Gellman, RD, electrolytes are always found in pairs, so a positive molecule (i.e., sodium) would be accompanied by a negative molecule (i.e., chloride). “It is important to consume these nutrients in proper balance for optimal health,” Gellman says. Why? “Because electrolytes are required for various bodily processes, like proper nerve and muscle function, water distribution and hydration, kidney and adrenal function, maintaining acid-base balance, and heart function.”

When to Drink Electrolytes

Not everyone needs to consume electrolyte drinks. In fact, drinking a sports drink when it's unnecessary could upset your body's delicate balance. “For example, too much sodium disrupts the balance, and a diet high in sodium and low in potassium may lead to high blood pressure,” Gellman says. Consider what your body needs based on the circumstances and adjust accordingly.

For Illness

If you're under the weather, when should you reach for Pedialyte or another electrolyte drink? “Anything that creates excessive fluid loss—like sweating, diarrhea, vomiting, urination, dehydration, some disease states, and use of some drugs—can create a risk of loss of electrolytes,” explains Gellman. People dealing with these symptoms should work to replenish their fluids by either drinking an electrolyte drink or consuming more fluids, like broth or juice.

For Exercise

As far as working out, the answer is more varied. “Yes, anyone who is exercising vigorously and sweating is losing electrolytes,” says Dr. Waitman. But that doesn’t mean you need to supplement. “Regular exercise should not warrant intake of electrolyte sports drinks,” explains Gellman. “Most workouts are fine, as long as you stay hydrated throughout and have a variety of fruits and vegetables afterward and throughout the day.

Symptoms of Low Electrolytes

If you believe you're low on electrolytes, both experts say to look out for symptoms such as fatigue, low blood pressure, and muscle spasms—but specific symptoms will vary depending on the mineral deficiency.

"For example, potassium deficiency may be characterized by confusion, irritability, weakness, heart disturbances, and issues with nerve and muscle contraction," Gellman explains. If you think your electrolyte balance may be off—or you feel dehydrated, and it won't go away—consult your doctor. They might suggest a simple blood test to determine the cause of your symptoms.

The Best Electrolyte Sources

“For mild dehydration, fruit juice and tea can be helpful,” Gellman says, adding that, in most cases, you don't need to drink an electrolyte drink to rehydrate your body. For healthy individuals, regular water consumption and a healthy diet are enough.

"For example, a smoothie with a range of fruits or vegetables and a protein-based liquid (such as kefir or yogurt) is a great way to replenish electrolytes,” says Dr. Waitman. “The best source of electrolytes is a healthy diet rich in whole foods, fruits, and vegetables.”

Sports Drinks Drawbacks

“Sports drinks do contain electrolytes—but they also contain lots of sugar or artificial sweeteners, which can have deleterious effects,” says Dr. Waitman. So before you run out for a bottle of something neon blue, try upping your intake of whole foods—fruits, veggies, whole grains—instead.

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