Do You Need Electrolyte Supplements at Altitude?

Here's what to keep in mind about hydration supplementation at all elevations

Photo: Getty/vgajic

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When Lara Crawford stopped into her local vitamin and supplement store a few months ago, she was in search of something to alleviate her acid reflux, which causes a burning sensation in her chest and acid regurgitation. But the conversation quickly took a turn when a staff member learned Crawford wasn’t taking electrolyte supplements.

Crawford lives at 9,000 feet in the Colorado Rockies, a place considered to be high altitude. Even after living in the mountains for years, she never saw a need for additional electrolytes. However, the staff member told Crawford those who live at altitude tend to get dehydrated overnight—and suggested she start taking sports salts pills and a daily electrolyte powder.

“I thought those were just for ultra athletes or like serious athletes, but he told me everybody should be taking them,” Crawford says. He spoke so convincingly about their benefits that she decided to give the electrolytes and sports salts a try.

After using the sports salts in the morning and the electrolytes at midday for a few months, she noticed a moderate improvement in her acid reflux. However, the biggest change was in her face: She no longer woke up with dry, puffy eyes.

Spotting the meaningful difference, she wondered if the staff member was right. Was the shift due to her new electrolyte supplements? Maybe these weren’t just for endurance athletes after all. Perhaps even people who only engaged in moderate exercise still needed to supplement with electrolytes at altitude.

Vic Johnson, an Utah-based sports nutritionist who works with outdoor athletes, including ultra runners, cyclists, and triathletes, says that while we do lose more fluids at altitude, there’s nothing special about nighttime.

However, the electrolyte and hydration question, and how much each of us should be consuming each day, is a bit more complicated.

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How Hydrated Do You Need to Be at Altitude?

At higher elevations, your body has to work harder to get oxygen, which causes your breathing rate to increase. Since you lose water through respiration, this results in greater fluid loss. The air is also drier at altitude, which makes your sweat evaporate faster and causes additional fluid loss. Each of these factors contribute to your body losing more water than at sea level, requiring you to hydrate more frequently.

However, the longer you stay up in the mountains, the better it gets. Johnson says people who live at altitude are able to adapt to the lack of oxygen. Their bodies become more efficient, producing more red blood cells to carry oxygen through the body, which reduces the amount of fluid lost.

“It’s going to be pretty stressful on your body for a couple of weeks,” Johnson says, referring to spending time at elevation. “That’s the most crucial time to increase fluid intake. Then things will kind of regulate, and you won’t have to compensate quite so much.”

However, even longtime residents of high altitude towns—Crawford has lived at 9,000 feet for 29 years—typically need about a liter to a liter and a half more water per day (about four to six cups) than people living at lower altitudes. But hydration isn’t a one-size-fits-all prescription. Whether you’re in the mountains or at sea level, your fluid intake varies based on the weather, the amount you exercise, and your overall health.

How Do You Figure Out the Right Hydration Level?

To help his athletes find the amount of hydration they need, Johnson performs a sweat rate test. He starts by weighing them before they exercise. While they work out, he keeps track of the fluids they drink and any urine they lose. After they’ve finished, he weighs them again and plugs each data point into an equation to figure out how many milliliters of sweat per hour they lose. (If you’d like to try this for yourself, use a step-by-step guide to finding out your own sweat rate.)

It’s important to note that even once you’ve figured out your sweat rate, completely replacing your lost liquids isn’t necessarily the goal. It’s not bad to be slightly dehydrated and more hydration isn’t always the solution. For many, drinking to quench your thirst is sufficient. (Those in their 70s or 80s need to monitor their intake a bit more, because our thirst sensation can decrease with age.)

Do You Need Electrolyte Supplements?

Electrolytes are electrically-charged minerals such as sodium, calcium, magnesium, and potassium that regulate your muscle contractions, keep you hydrated, and balance your pH levels. Every fluid and cell in your body has electrolytes, which aid the function of your nerves, muscles, brain, and heart. Electrolytes also manage the balance of fluids in your body’s cells and are lost through sweat and urine, or if you’re sick, through vomiting and diarrhea.

While electrolytes are essential, Johnson says most of us get all we need from food. “A normal, varied diet should provide you with plenty of electrolytes, even at altitude.” Johnson says, “For the recreational athlete, it’s honestly not that big of an issue.”

If you aren’t engaging in high-output endurance activities lasting longer than three hours, and if you’re eating a nutrient-dense diet with whole grains, legumes, vegetables, fruits, nuts, and seeds, Johnson says you should be getting enough electrolytes without needing additional supplementation. However, endurance athletes who engage in high-output endurance activities lasting longer than three hours have different hydration needs, and may find electrolyte powders and capsules are a good way to stay hydrated and keep their electrolytes balanced.

That doesn’t mean these supplements are the secret to unlocking a new PR. A 2020 study conducted by researchers at Stanford University found that electrolyte supplementation does not improve performance or protect against illnesses caused by a change in sodium levels, including exercise-associated hyponatremia (EAH).

If an endurance athlete wants to take in some sodium, Johnson recommends turning to salty foods, such as pretzels or even a peanut butter sandwich.

“For the most part, when our serum sodium levels drop, the body can usually take care of that and regulate that on its own,” he says.

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The Power of Hydration

So, if electrolyte supplementation isn’t really necessary for most people, why did Crawford see a noticeable difference in her face after months of supplementation?

The answer most likely lies in what Crawford took with the powder and capsules.

Before going to the supplement store, Crawford says she struggled to drink enough water. However, while doling out instructions for the supplements, the staff member instructed Crawford to drink a full bottle of water with her morning sports salts capsules (which contain sea salt, magnesium, and potassium) and to mix the flavored electrolyte powder with at least 16 ounces of water later in the day. The supplements provided the structure for her to consume more water, improving her overall hydration and reducing the puffiness in her eyes.

If you live at altitude and find it difficult to drink adequate fluids, a flavored powder might help. For most people, however—including serious athletes—drinking when you’re thirsty is usually enough.

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