Electrolyte supplements are everywhere. Who benefits from them and when?

We lose some electrolytes through sweat, primarily sodium chloride — which is what is in table salt. Drinking too much plain water when sweating very heavily can dilute the salt in your body even further, throwing things out of balance. Electrolyte drinks and powders are meant to hydrate and replace the lost salt. They often contain other electrolytes like potassium and magnesium. Many also contain some form of sugar.

In general, the kidneys in a healthy person do an excellent job of keeping our electrolytes in balance. Extras simply come out in your urine, said Vanderbilt University nephrologist Hunter Huston, who also consults for a UK-based company that provides electrolyte replacement plans for endurance athletes.

Taking "an electrolyte-enriched drink, just for health purposes, probably isn’t doing much," he said.

Today “rapid hydration” and “advanced hydration” drinks are taking off, but who actually benefits from them and when?

It all started with Gatorade

It was 1965 at the University of Florida and then-assistant Gators football Coach Dwayne Douglas had something on his mind. As Robert Cade, the school's first kidney researcher, later explained, Douglas asked him, “Doctor, why don’t football players wee-wee after a game?”

“That question changed our lives,” Cade said.

The obvious answer was that the football players couldn't urinate because they were losing so much fluid through sweat. Cade’s research team determined a player could lose as much as 18 pounds (8.16 kilograms) during a game. But it wasn't just water the players were losing. They were sweating away sodium and chloride and losing both plasma volume and blood volume. The losses were sapping their strength and stamina.

Cade mixed up a briny solution to replace the water and salt players were losing. Sugar would help the gut absorb the sodium. The first batch made him vomit. Some lemon juice made it taste a little better. It still wasn't delicious, but soon the team’s performance improvement could not be ignored — especially in the second half of games when the opposite team's players were starting to wilt in the Florida heat and humidity.

Cade, who died in 2007, said he never dreamed Gatorade would be purchased by regular consumers.

No one-size-fits-all

While it seems that everyone is drinking electrolyte supplements these days, not everyone actually needs them.

A good rule of thumb is that if you are exercising for less than two hours, plain water is probably fine, said Vanderbilt's Huston. The average healthy person can tolerate losing around 2% of their body weight in sweat before they really start to feel it, he said. “That’s increased thirst, it’s fatigue, it cramping.”

Everyone is different, though. Some people sweat very heavily or have sweat that is especially salty.

In the world of extreme sports like ultramarathons, athletes often get professional help to test how much they sweat and get a tailored nutrition plan.

“Most folks that are exercising, that are, say, doing a marathon, are gonna be way past that two hours, and it does then make sense to be thinking about, ‘What’s going to be my fluid and electrolyte replacement plan?’” Huston said.

Aspirational athletes

Darren Rovell has followed the rise of sports drinks from a niche market to the mainstream. He is the author of “First in Thirst: How Gatorade Turned the Science of Sweat Into a Cultural Phenomenon” and was an investor in the sports drink Bodyarmor.

When he was a runner in high school, he said, they were given Gatorade to drink and told the reason it tasted bad was because it was good for you. “And then at some point in the nineties, it got to be sugary.” After PepsiCo purchased the brand in 2001, “that really became the first time where you see Gatorade everywhere in front of your face including in a pizza place, and it starts to be, ‘OK. Is this just a different type of soda?’"

Rovell says electrolyte brands market the idea that drinking their products will either make you an athlete or, if you already are an athlete, give you a performance edge.

“It all starts in the aspiration of being better, but you know we do have to check ourselves,” he said.

A flood of newer options

The supplements out today have an incredibly wide variety of electrolyte concentrations, said Patrick Burns, who practices emergency medicine at Stanford Health Care and occasionally runs in ultramarathons. With some having five times the sodium of others, consumers should not assume all supplements are the same.

Burns also warned that people should be careful about supplementing potassium, because it can be dangerous in large amounts.

He noted that many brands now offer zero sugar varieties, even though the glucose in sugar is what allows for rapid absorption of the sodium.

“They’re not internally consistent, at all, with what they’re trying to sell you,” he said. “For optimal absorption, you need some sugar in with your salt.”

The bottom line

“Electrolytes can help, especially with heavy sweating or exercise, but for most people, they’re not something you need every single day, and you definitely don’t need large amounts of it,” the Cleveland Clinic's Zumpano said.

For a healthy person who is not sweating intensely, the beverages probably won't hurt you, but they won't help you either.

“You’re getting extra sugar, and there’s no reason (for) rapid absorption of sodium because you’re not sodium depleted," said Mark Segal, a professor of nephrology at the University of Florida College of Medicine. Most people get all the salt and potassium they need from food, he said.

As far as making your own electrolyte powders, the experts said it can be done, but you have to know what you are doing. They advised against using a recipe from an influencer.

“How do you know how much you need?” Zumpano asked. “There's a large margin of error there. I'd probably just avoid it.”