Most people know that hydration is important. But unfortunately, most people also think about hydration incorrectly.
It’s not their fault. From a young age, we’re led to believe that more water is always better. People think that if we don’t drink 8, 8-ounce glasses of water per day, we’ll shrivel up like a prune in Death Valley. This 8×8 rule is widely accepted as fact, but is there any science behind it? Not really. Well, to be more direct… NO.
So where does this misguided idea come from? 8×8 seems to have originated with Irwin Stillman, a doctor from the 1960s who wrote a few popular diet books. He advised drinking 64 ounces of water per day, which was actually down from the US National Academy of Science’s 84-ounce target set in the 1940s. Neither target is backed by scientifically rigorous data. Some relatively recent papers have explained this better than I ever could.[*][*]
This confusion around hydration creates consequences. It’s why many athletes overhydrate with plain water and consequently experience symptoms of low sodium levels. This condition, called exercise-associated hyponatremia, is fairly common and quite dangerous, particularly in endurance sports.
It’s also why folks on low-carb diets, whole foods diets, or fasting regimens struggle to feel their best. One thing all these people have in common: their sodium needs are greater than someone on a Standard American Diet (SAD). So they’re getting enough—or even too much—water, but they’re neglecting the other component of hydration: electrolytes, specifically sodium.
When they address this electrolyte oversight, people often unlock many benefits, and almost immediately: better energy, mental function, sleep, athletic performance, and more. I’ll cover each of these benefits in greater detail soon. Before that, though, let’s dip our toes into the basics. First up: the right way to think about hydration.
How To Think About Hydration
Think of hydration as a process that requires two inputs:
- Water
- Electrolytes
Most people get enough water, if not too much. The truth is, healthy people with healthy kidneys and sweat glands rarely become dehydrated.
Why? Because when we need more water, special receptors in our brain pick up on it. They tell a brain structure called the hypothalamus that blood volume is low, and we get thirsty. Then we drink something.
We don’t have such an elegant system for electrolyte intake. We have to rely on dietary choices for these crucial minerals.
Yes, we do crave salty things. And this helps us get enough sodium. But our sodium craving isn’t quite as powerful as the very reliable system known as thirst.
And electrolytes (sodium in particular) are essential for hydration. Don’t just take my word for it, though—let’s unpack the science behind why this is true.
Why Fluid Balance is Important
If you look up hydration in a medical textbook, you’ll find continual references to fluid balance. Hydration is all but synonymous with this term.
Fluid balance describes how water is distributed throughout your bodily tissues. And since we’re mostly water weight, this distribution matters.
Think about it. What makes your blood flow? What keeps your skin moist? How do you excrete toxins through sweat, urine, and feces? Fluids.
Proper fluid balance (aka, healthy hydration) means all this machinery is running smoothly. It means that blood, sweat, tears, and pee flow properly, among other functions.
Along with water, the electrolytes sodium and potassium are key constituents in this system. Sodium regulates fluid outside your cells, while potassium regulates it inside cells.
For the most part, your body does a nice job maintaining fluid balance without any conscious direction. Consider that:
- If you drink too much water, you’ll excrete more fluids through urine.
- If you don’t drink enough water, your brain will tell you via the thirst mechanism.
- If you consume too many electrolytes, you’ll excrete more electrolytes through urine.
- If you consume too few electrolytes, your body will pull these minerals from bone. (That’s how important they are!).
That last bullet doesn’t sound so good, does it? That’s because it’s not.
Just because blood levels of electrolytes return to normal, it doesn’t mean hydration status is optimal. You can pass a blood panel but still be electrolyte deficient.
The takeaway? Hydration isn’t just about water. It’s about water PLUS electrolytes. Consume both in the right amounts, and your body shouldn’t have to take minerals away from your bones to keep you feeling and performing well. Personally, I’m a fan of that.
10 Benefits of Staying Hydrated
When you consume sufficient water and electrolytes, your bodily fluids will be nicely balanced. Here’s how your body will thank you.
#1: Better energy
Low energy is a red flag for sodium deficiency. I see it all the time, especially in athletes (who lose extra sodium through sweat) and low-carb dieters (who lose extra sodium through urine).
Addressing my own sodium deficiency eventually led my coaches and I to co-create LMNT, our tasty electrolyte drink mix. Once I dialed in my electrolytes, I felt like a whole different animal on the jiu-jitsu mat—and I felt better doing everything else too. Many of the symptoms I’d attributed to blood sugar or other issues was, in fact, inadequate sodium intake.
Fatigue is also a symptom of dehydration, but most people aren’t low on water. They’re low on electrolytes.
#2: Improved brain function
Brain fog is another common symptom of both dehydration and sodium deficiency. And again, low sodium is the bigger problem.
Sodium is critical for brain function. Along with potassium, it conducts electricity between brain cells so you can read these words or daydream about your next meal while you idly scan them.
Your brain also depends on proper fluid balance to stay suspended in cerebrospinal fluid. Yet another reason to drink electrolyte water.
#3: Fewer muscle cramps
Most people believe that dehydration causes muscle cramps, but the science says otherwise. Even losing 5% of one’s body weight in water (severe dehydration) doesn’t increase cramp frequency.
A more likely cause is electrolyte deficiency. In the 1920s, salt supplementation reduced cramping in industrial workers, and more recently, football players with saltier sweat cramped more frequently than their teammates.
Get the right amount of sodium for proper fluid balance and you’ll cramp less. Simple as that.
#4: Fewer headaches
A headache can have many causes. Two of the potential causes are dehydration and electrolyte deficiency—so if you aren’t hydrating with water and electrolytes, headaches may follow.
I see this keto flu symptom a lot. Keto and Paleo folks tend to consume less salt than the general population while simultaneously excreting more of it. It’s a recipe for disaster, and a big reason why many folks give up on their low-carb diet.
#5: Better performance
When you sweat, you lose both water and sodium. Both need to be replaced to keep your body humming along.
Visit the finish line of any marathon and you’ll see the consequences of replacing only H2O. A large percentage of endurance athletes need medical care, often in the form of intravenous saline.
The more you sweat, the more sodium you’ll need. In warm climates, athletes can lose up to 7 grams of sodium per day!
#6: Makes fasting and keto easier
Both keto and fasting keep the hormone insulin low. Low insulin then signals your kidneys to excrete more fluids and electrolytes through urine.
The resulting deficiencies cause a constellation of symptoms—headaches, low energy, brain fog, cramps—called keto flu. Bumping up electrolytes (especially sodium) generally fixes it.
#7: Healthy blood pressure
High blood pressure (hypertension) is a well-documented heart disease risk factor. Electrolytes are important for mitigating this risk.
Potassium in particular has been extensively studied in this area. Higher potassium intakes are correlated with lower blood pressures, and potassium supplementation has been clinically shown to decrease bp in those with hypertension.
What about sodium? Doesn’t sodium cause high blood pressure?
Actually, sodium restriction has been linked to higher blood pressures in data from the Framingham Study. And global population data has found no strong link between sodium intake and hypertension.
#8: Smoother digestion
Staying hydrated is essential at all stages of digestion. Water is the lubricant that keeps things moving along down there.
Magnesium can also help with constipation. The form most studied for it’s laxative effect is magnesium oxide.
#9: Skin health
Skin health depends on hydration status. If you’re not hydrating properly, you may end up with dry skin or cracked lips.
But dry skin doesn’t prove you’re dehydrated. This condition, like most, is multifactorial. Zinc deficiency, vitamin A deficiency, low ambient humidity, and many other factors affect skin health.
#10: Improved sleep
The main electrolyte studied for sleep is magnesium. Supplementing with magnesium has not only been shown to reduce insomnia but also to increase deep sleep in elderly people.
Sodium affects sleep too. It’s been shown, for instance, that a sodium-restricted diet decreases deep sleep, REM sleep, and wakefulness overnight.
Why? Because salt restriction stimulates the release of adrenaline, a stimulating chemical that helps you retain sodium.
How To Stay Hydrated
Your body is good at regulating water intake. You simply drink when thirsty.
It’s not as adept, however, at nudging you to consume electrolytes. That’s why you need to consciously ensure you’re getting enough.
How much is enough? Based on the literature, I recommend shooting for 4–6 grams of sodium, 3.5–5 grams of potassium, 400–600 mg magnesium, and 1 gram of calcium per day.[*][*][*]
Sodium is the most common deficiency. And if you sweat profusely, practice fasting, eat a low-carb, paleo diet, or whole foods diet, or any combination of the above: you may need a good deal more than that 4–6 gram baseline.
Calibrate your sodium intake based on how you feel. Take into account your energy, mental function, muscle cramps, headache frequency, and sleep. Staying salty can help in all these areas.
For a lot of folks, sodium is the missing link to optimal hydration. So if you recall one thing from this chat, remember to drink electrolyte water to thirst. Hydration = water + electrolytes.
