What influences electrolyte needs? Diet, lifestyle, and other factors

We all know we need electrolytes, but how many of each do we need on a daily basis? You’re going to love this… It depends! Since different people live different lifestyles, you’ll have to endure a little rant from me. In the process, you’ll learn about the various dietary, lifestyle, and other factors influencing electrolyte needs.

Specifically, I’ll focus on sodium, potassium, and magnesium. Sodium is the number one electrolyte lost through sweat, and most of today’s factors (like ambient temperature) matter because they increase sweat rate. The more you sweat, the more sodium you need.

But I’ll also cover potassium and magnesium where it makes sense. Only 3% of Americans get enough potassium, a crucial electrolyte for regulating blood pressure. And up to 30% of people are deficient in magnesium, a mineral required for over 300 enzymatic reactions, including the formation of cellular energy itself (ATP).

My hope is that I’ll share some science you haven’t encountered, and teach it to you in a way that sticks. I want to help you make more informed health decisions. Let’s start by reviewing electrolyte status. Then, we’ll cover factors influencing that status. I’ll wrap up with practical tips on getting enough sodium, potassium, and magnesium. Sound good? Let’s go.

Electrolyte Status: Deficiency vs. Imbalance

I want to make an important distinction right away: An electrolyte deficiency is not the same as an electrolyte imbalance. 

An electrolyte deficiency is when you don’t consume enough of a given electrolyte for optimal health. It’s unlikely to appear on a blood test, but you’ll pay the price nonetheless. Subtle symptoms like fatigue, weakness, cramps, and headaches are common with sodium deficiency, for instance. But symptoms may also be imperceptible, like elevated blood pressure from potassium deficiency or inflammation from magnesium deficiency.

An electrolyte imbalance is when blood levels of an electrolyte become too high or too low. It’s a serious medical condition that will, of course, appear on a blood test. Electrolyte imbalances are more often the result of serious medical issues—heart failure, prescription drugs, kidney failure, and alcohol abuse—than the more widely applicable factors we’ll discuss today.

Dietary Factors 

Most of our electrolytes should come from food — there are plenty of potassium and magnesium-rich sources out there, especially if you’re prioritizing whole foods! Sodium, on the other hand, can require some conscious shaking of the salt shaker (or conscious inclusion of foods like pickles, olives, and bone broth). Certain diets in particular require more intentional consumption to make sure we’re getting the nutrients we need.

Whole foods diets 

When folks move from a modern, Western diet to a whole foods diet, I’m happy for them. But since over 70% of US salt intake comes from packaged or prepared foods, they need to get jiggy with the salt shaker (or a well-formulated electrolyte drink) to prevent sodium deficiency.

Low-carb diets

Sodium deficiency is even more likely if your whole foods diet is low in carbs. Why? Low-carb diets (like keto, paleo, and carnivore) keep your blood sugar low.

Low blood glucose, in turn, minimizes your body’s need for the hormone insulin. And when insulin is minimized, your kidneys high-tail it into sodium excretion mode — meaning, you pee out more sodium. Low blood glucose also suppresses a sodium-glucose cotransporter called SGLT-2, which further contributes to sodium losses.

Lastly, it’s important to acknowledge that many high-carb foods—fruits, potatoes, grains—are rich sources of potassium and magnesium. Reducing or excluding these foods from your diet can make it harder to get enough electrolytes.

Fasting

Similar to low-carb dieting, fasting depletes sodium via insulin suppression and SGLT-2 suppression.

When fasting for longer than 16 hours, we begin to excrete sodium rather quickly. According to one review, a person can lose anywhere from 1,100 to 5,700 mg of sodium in the first 24 hours of a fast. If you’re fasting for an extended period of time, other studies indicate that heavy losses will continue through day 3 or 4 and then decelerate to a low plateau by day 10.[*][*][*]

Shorter fasts of 12–16 hours may not induce significant sodium losses, but you’re not eating during those periods. That means you’re not getting any sodium from food for a while. Supplementing sodium, potassium, and magnesium can help you hit your baseline targets (and feel better) during a fast.

Lifestyle Factors

The following lifestyle factors are mostly related to exercise. They influence electrolyte needs because they influence sweat rate. Anything that contributes to perspiration raises sodium needs considerably, and potassium and magnesium needs marginally.

Exercise intensity

The effect of exercise intensity on electrolyte needs won’t surprise you. The more strenuous the effort, the more your core body temperature rises, the more you sweat, and the more electrolytes you lose. To illustrate, a 2021 study on soccer players found that shifting from low to high-intensity efforts more than doubled sweat rates.

But here’s a lesser-known fact: the higher your sweat rate, the saltier your sweat. Why? Because when you sweat more, less sodium gets reabsorbed before sweat reaches the skin. Consequently, your final sweat is saltier. 

One study found that increasing exercise intensity from 50% to 90% of max heart rate increased sweat rates by 328% and sweat sodium concentrations by 311%. The takeaway is that intense efforts demand serious sodium support.

Exercise duration

Sodium needs also rise with exercise duration, but not linearly. As the session drags on, sweat rates can go down due to sweat gland blockage. This effect (hidromeiosis) typically occurs after 1–2 hours of moderate to intense physical activity.

Hidromeiosis impairs your cooling system, increasing the risk of heat illness. I recommend being super careful with extended bouts in hot, humid conditions.

Hydration habits 

Hydration status is inseparable from sodium status. Dehydrated folks need less sodium (until they replenish water losses), while overhydrated folks should seek out sodium.

Dehydrated folks need less sodium because they sweat less. A 1985 study suggests mild dehydration decreases sweat rates by 5–15%, while severe dehydration decreases sweating by around 50%.

Overhydration, on the other hand, raises sodium needs. When you drink too much plain water, it can dilute blood sodium levels and cause a dangerous sodium imbalance called exercise-associated hyponatremia. This is the only lifestyle factor I’m covering which can catapult you straight past electrolyte deficiency into electrolyte imbalance.

Thankfully, drinking salty fluids to thirst (not beyond it) is a super simple and effective way to remain properly hydrated, ensuring that neither dehydration or overhydration influence your electrolyte needs.

Environmental Factors

Your environment also influences your sweat rate. Just observe the sweat-soaked Tiger Woods during one of his golf tournaments in the Bahamas. Anecdotes aside, I have some more scientific examples coming up.

Ambient temperature

The warmer it gets, the more you sweat. Higher ambient temperatures raise skin temperature, triggering sweat that evaporates to cool you off. In the soccer study mentioned above, players sweat about 50% more when exercising at 84°F vs. 60°F. 

And so, you’ll need more electrolytes if you’re getting after it on a summer scorcher, or teeing off in the Bahamas.

Humidity

You also need more electrolytes on humid days. When the air is thick with moisture, your sweat evaporates more slowly, reducing its cooling effect.

Since maintaining a healthy core body temperature is the main reason we sweat, our body has to make up the shortfall! On humid days, you’ll sweat more for the same degree of cooling compared to dry environments. 

In a 2012 study, 8 cyclists had a 36% higher sweat rate when cycling to exhaustion in a humid room (80% relative humidity) vs. a dry room (24% relative humidity.) The athletes also became exhausted faster during the humid trial. No surprise there, since humidity impairs thermoregulation. Don’t expect to achieve your personal best on a sticky day, folks.

Breeze

Stagnant, windless conditions aren’t ideal for thermoregulation. Without airflow, more sweat drips off your body and less sweat evaporates. Much like with humid environments, that means less bang for your buck—less cooling power for your sweat.

Conversely, you require less sweat to cool down when there’s a breeze in the air or a fan in the room. That means you have to replace less fluid and electrolytes.

Clothing

Fashion? What’s that? Your attire should exist solely to promote maximum ventilation while keeping you reasonably comfortable.

I’m only half kidding. In one study on people exercising at -4°F, Army researchers found that reducing the warmth factor of gear by half decreased sweat rates by a factor of five. In other words, the wrong outdoor gear could massively increase your electrolyte needs.

Altitude

Increasing altitude can raise or lower electrolyte needs, depending on the situation. For the first several days spent adjusting to the ascent, folks may need more fluids and sodium due to altitude-induced diuresis (more pee) and higher sweat rates.

But after about a week in the peaks, around 25% of people develop a condition of excess water retention called Acute Mountain Sickness. Treatment often entails fluid and sodium restriction, diuretics, or other medications. Read our deep dive on winter hydration for more details.

Conditions and Other Factors

Pregnancy, nursing, illness, and various medical conditions can increase electrolyte needs. It’s impossible to cover everything, but here are the highlights.

Pregnancy and breastfeeding

Expecting moms should strive to avoid sodium deficiency. Research suggests inadequate sodium intake can cause growth issues and organ dysfunction during childhood development. Sodium is also a key component in breast milk, so moms need plenty of salt when nursing. Anecdotally, we’ve heard from many new moms reporting improved breast milk production after using LMNT.

Potassium and magnesium matter too. Potassium helps pregnant women maintain healthy blood pressure, and magnesium supports fetal development. In one study, women taking 300 mg of magnesium per day had fewer pregnancy complications than those taking 100 mg/day.

Illness

If you have an illness that causes diarrhea or vomiting, you’ll lose significant potassium. Other diseases (like the flu) can cause fever and sweats, increasing sodium and magnesium needs. Rehydrating with fluids and electrolytes is crucial during these times.

Medical conditions

The following medical conditions can increase electrolyte (especially sodium) requirements:

• Postural orthostatic tachycardia syndrome (POTS) 
• Orthostatic hypotension (OH) 
• Gitelman syndrome
• Bartter syndrome
• Hyperhidrosis (excessive sweating)
• Night sweats
• Cystic fibrosis
• Ovarian hyperstimulation syndrome (OHSS)

What about hypertension, heart disease, and type 2 diabetes? The traditional advice is sodium restriction, but randomized controlled trial data suggest low-sodium diets (below 2.3 grams/day) don’t improve outcomes like heart attack or mortality.

Also, two extensive analyses of population data—see here and here—suggest that moderate intakes are the sweet spot for both healthy and at-risk groups. To be conservative, current evidence suggests high-risk groups should shoot for 3–4 grams/day as a baseline.

Rather than eating a low-sodium diet, it seems that increasing potassium intake is a better way to decrease one’s risk of hypertension, heart disease, and mortality.

How to Get Enough Electrolytes

To optimize your electrolyte status, start with a baseline intake and calibrate your consumption based on the factors I covered today. Science-backed baseline intakes for sodium, potassium, and magnesium are:

• 4–6 grams of sodium (3–4 grams for high-risk groups)
• 3.5–5 grams of potassium
• 400–600 mg of magnesium

Assuming you eat a whole foods diet, you likely won’t get enough sodium through the foods you’re eating alone. Get friendly with the salt shaker or an electrolyte drink mix like LMNT, which has 1,000 mg sodium per stick pack. When you drink your electrolytes, you prevent dehydration and electrolyte deficiency in one go. And remember, you may need significantly more than 4–6 grams if you’re sweating a lot, restricting carbs, or fasting.

Potassium and magnesium are easier to consume from dietary sources (especially green leafy vegetables), but consider supplementing if your diet falls short of these targets. In my experience, most people could benefit from supplementing 1 gram of potassium and 300 mg of magnesium malate daily, in addition to their diet. Avoid poorly absorbed forms of magnesium like magnesium oxide.

Bottom line? Dial in your baseline strategy to your situation, and you’ll be in good shape to optimize your electrolyte status.