A good electrolyte drink for general exercise should contain roughly 230 to 690 mg of sodium per liter, which translates to about 300 to 600 mg of sodium per hour of activity. That range covers most people in most situations, but the right number for you depends on how long you’re active, how much you sweat, and why you’re drinking it in the first place.
The Standard Range for Exercise
The American College of Sports Medicine recommends 500 to 700 mg of sodium per liter of fluid for exercise lasting longer than one hour. That concentration hits a sweet spot: it promotes fluid retention, helps your gut absorb water efficiently, tastes acceptable, and protects against dangerously low blood sodium levels during prolonged activity. In practice, the goal is to take in 300 to 600 mg of sodium per hour while exercising.
For workouts under an hour, plain water is usually sufficient. Your body has enough sodium reserves to handle a short session without supplementation. The need for sodium in a drink becomes more important once you cross the one-hour mark, exercise in heat or humidity, or notice white salt stains on your clothing after a workout (a sign you’re a heavy salt sweater).
Why Sodium Matters for Absorption
Sodium isn’t just there to replace what you lose. It plays an active role in pulling water through your intestinal wall. Your small intestine has a transport system that uses sodium and glucose together to move water into your bloodstream. Research has identified an optimal sodium-to-glucose ratio of roughly 0.64 to 0.82 for maximum fluid absorption, with the sweet spot around 0.73. The most effective oral rehydration formulas, including the one recommended by European pediatric guidelines, use this ratio.
This is why a drink with some sodium and a small amount of sugar rehydrates you faster than plain water. It’s also why drinks that are very high in sugar but low in sodium can actually slow absorption down. The balance between the two ingredients matters more than loading up on either one alone.
How Commercial Drinks Compare
The electrolyte drink market spans an enormous range. A standard sports drink like Gatorade contains about 50 mg of sodium per serving, which is quite low. Mid-range products like Electrolit come in around 330 mg. High-sodium options marketed to endurance athletes or people with specific medical needs can reach 1,000 mg per serving or more.
For a casual gym session or light activity, a lower-sodium drink is fine. For longer or more intense exercise, especially in the heat, you’ll want something closer to the 300 to 600 mg per hour range. One thing to keep in mind: sodium concentrations above 1,000 mg per liter tend to make drinks taste unpleasantly salty, which means you’re less likely to drink enough of them. Palatability matters because a drink you won’t finish doesn’t help you.
Endurance and Ultra-Endurance Events
If you’re running a marathon, competing in a triathlon, or doing any activity lasting four hours or more, sodium becomes critical. Exercise-associated hyponatremia, a dangerous drop in blood sodium, most commonly occurs during prolonged exercise of four to six hours. It happens when athletes drink large volumes of plain water without replacing the sodium they’re sweating out, effectively diluting their blood.
For these longer efforts, the recommendation stays at 300 to 600 mg of sodium per hour, but consistency matters more. You need to keep up that intake throughout the event, not just at the start. Fluid intake itself should be moderate, around 300 to 600 mL per hour, to avoid overhydration. Drinking to thirst rather than forcing fluids is a reliable strategy, as long as what you’re drinking contains adequate sodium.
Sweat sodium concentration varies widely between individuals, ranging from about 230 mg to over 1,600 mg per liter of sweat. If you’re on the higher end of that spectrum, you may need to aim for the upper portion of the recommended range. Sweat testing, offered by some sports nutrition services, can give you a personalized number.
Medical Rehydration Is Different
Electrolyte drinks designed for illness recovery or clinical dehydration use different formulations than sports drinks. The World Health Organization’s oral rehydration solution contains about 90 mmol/L of sodium, which works out to roughly 2,070 mg per liter. That’s significantly higher than a sports drink, and it’s designed for severe dehydration from conditions like cholera or acute diarrhea.
In developed countries, where dehydration from illness tends to be milder, a lower concentration of 50 to 60 mmol/L (about 1,150 to 1,380 mg per liter) is often preferred. Pedialyte and similar products fall in this range. These are not interchangeable with sports drinks, and the higher sodium content reflects the greater fluid losses that come with vomiting and diarrhea compared to exercise.
Conditions That Require More Sodium
Some people need significantly more sodium than the general population. Postural orthostatic tachycardia syndrome (POTS) is a common example. People with POTS typically have lower blood volume, and increasing salt and fluid intake helps manage symptoms like dizziness and rapid heart rate. The recommended additional salt intake for POTS is 6 to 10 grams per day, which is roughly one to one and a half teaspoons of table salt on top of what’s already in food.
Electrolyte drinks or tablets can help reach that target, with most products providing 0.3 to 0.8 grams of salt per serving. People with heart disease, kidney problems, or high blood pressure need individualized guidance, since extra sodium can worsen those conditions.
Keeping Total Daily Sodium in Check
For the general population aged 14 and older, dietary guidelines recommend staying under 2,300 mg of sodium per day. That includes everything: food, drinks, and supplements. Most people already consume more sodium than they need from food alone, so adding a high-sodium electrolyte drink on a rest day or after a light workout can push intake well past that limit without any real benefit.
The key is matching your electrolyte drink to your actual needs. A 30-minute walk doesn’t call for the same drink as a three-hour bike ride in July. For everyday hydration, water is still the baseline. Electrolyte drinks earn their place when you’re sweating hard, sweating long, or recovering from illness. Choose a sodium level that fits the situation: 200 to 500 mg per serving for moderate exercise, 500 mg or more per serving for intense or prolonged efforts, and medical-grade formulations only when you’re dealing with significant dehydration.