How Much Sodium Per Day? Why Sweating Bodies Need More Than the Label Says

Think a hydration mix that puts sodium up front missed the memo on how much you're supposed to get per day? Reality check: that sodium guideline was written for the average person on an average day, sitting mostly still. If you sweat hard (on a long run, a hot job site, or a brutal gym session), your body plays by different rules. So the real answer to how much sodium per day you need is that it depends on how much you sweat, and the science behind that is solid.

How Much Sodium Per Day Most People Should Get

Start with the official numbers from the FDA, because they aren't wrong, they're just not the full picture: keep sodium under 2,300 milligrams per day. The American Heart Association goes further, setting an optimal target of 1,500 mg a day for most adults.

The 2,300 mg ceiling works out to about one teaspoon of table salt. Your body actually needs surprisingly little to work (under 500 mg a day), and it's pretty rare to fall short on that: the average American takes in roughly 3,400 mg, according to the FDA.

The whole reason you reach for an electrolyte drink is that you've been sweating more, which is exactly the situation where you need more sodium than that. We build our formulas around what sweat takes out, not the trace amount that looks reassuring on a label. That's why we don't have a "low-sodium electrolyte drink."

Why There Is a Limit in the First Place

Sodium attracts water (that's "hydrophilic," for you nerds out there). So, a high-sodium diet pulls more water into your bloodstream, raises blood volume, and nudges your blood pressure up. Over time, high blood pressure (hypertension) makes the heart work too hard and can raise the risk of heart attack, heart failure, stroke, and kidney disease. That's why excess sodium is treated as a cardiovascular disease issue.

Not everyone reacts the same way to sodium, though; about half of people with high blood pressure see it climb when sodium goes up, and roughly one in four people without high blood pressure are salt-sensitive too. That's why the official guidelines aim low for the general population.

High-Sodium & Low-Sodium Foods

Most of the sodium in a typical diet comes from processed and packaged foods, including:

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  Processed meats (like deli meats and cold cuts)

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  Bread

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  Pizza

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  Soups

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  Canned foods

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  Snack foods

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  Dairy products (like butter, milk, and cheese)

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  Condiments (like ketchup and soy sauce)

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  Restaurant or fast food

Even foods that don't taste salty add up, and some surprising ones, like shellfish, run high, with roughly five to eight times the sodium of similar meats. Fruits and vegetables tend to carry more potassium than sodium, while processing usually adds sodium and removes potassium (a mineral that helps offset some of sodium's effects, which we include in our electrolyte packets, too).

Table salt is sodium chloride (about 40% sodium), and ingredients like monosodium glutamate (MSG) and sodium bicarbonate (baking soda) also count as sodium. The Nutrition Facts label adds all of it up, which is where reading food labels comes in handy.

Food packaging might say things like:

• Sodium-free (under 5 mg a serving)
• Very low sodium (35 mg or less)
• Low sodium (140 mg or less)
• Reduced sodium (25% less than usual)
• Light in sodium (at least 50% less)
• No salt added/unsalted (none was added in processing)

Fresh fruits and vegetables, whole grains, and herbs and spices are naturally lower-sodium options, with salt substitutes as another option some people use.

How Much Sodium You Sweat Out & How To Get it Back

So how much do you actually lose? Sweat sodium generally runs from roughly 400 to 1,500 mg per liter. Sweat out a couple of liters on a long run or a hot shift, and you can lose more than a thousand milligrams of sodium through your skin.

Water on its own is absorbed slowly, and your body pulls water across the gut wall faster with a little sodium mixed in, through a process called sodium-glucose cotransport. It's the same principle behind the oral rehydration solutions used in hospitals. Pour in liter after liter of plain water after heavy sweating, and you can dilute the sodium left in your blood, which, at the extreme, can lead to a dangerous condition called hyponatremia.

Putting water and sodium back together is what actually rehydrates you.

Match Your Sodium to Your Sweatiness

So, how much sodium per day? If you spend your day mostly still, the standard guidance is a solid target, and most of us would be better off closer to it. But if you sweat for a living or for fun, your body is running a different math problem, and a little sodium is doing real work.

When you want a mix built to replenish what you lose through more sweat than usual, Waterboy's Daily Hydration packets are the place to start.

Frequently Asked Questions