What Are Electrolytes? Sodium, Potassium and Magnesium Explained
What each electrolyte does, how much you need, and where sweat fits in.
You hear the word electrolytes in every sports drink ad. Here is what it actually means, and what each one does.
What makes something an electrolyte
An electrolyte is a mineral that dissolves in water and carries an electrical charge. Your body uses those charges to send nerve signals, contract muscles, and keep fluid in the right places. The ones that matter most for hydration are sodium, potassium, magnesium, calcium, and chloride.
Sodium and chloride: the fluid balance pair
Sodium and chloride are found mostly in the fluid outside your cells. They help set how much water your blood and tissues hold, and they are the main electrolytes in sweat. Table salt is sodium chloride.
U.S. dietary guidelines suggest adults keep sodium under 2,300 mg a day, and the Daily Value on labels uses that number. On average, people in the U.S. already eat more than that, so extra sodium matters mainly for people who sweat a lot.
Potassium: the inside partner
Potassium lives mostly inside cells. It works with sodium to keep nerve signals and muscle contractions running and to balance fluids. The Daily Value is 4,700 mg, and many people eat less than the amounts experts recommend. Potatoes, beans, yogurt, and bananas are common sources. Sweat contains far less potassium than sodium.
Magnesium: the enzyme mineral
Magnesium takes part in hundreds of enzyme reactions, including those that make energy and let muscles relax. The Daily Value is 420 mg, and recommended daily amounts for adults range from about 310 to 420 mg depending on age and sex. Leafy greens, nuts, seeds, and whole grains are the main sources. Sweat carries only a small amount.
Where sweat fits in
Sweat is mostly water with sodium and chloride, plus smaller amounts of potassium, magnesium, and calcium. If you sweat for an hour or less, food and water usually cover it. Long sessions, heat, and heavy sweating are when replacing sodium in particular becomes useful.
What to look for on a label
- The amount of each mineral in milligrams, not only a total.
- Daily Value percentages, so you can see how one serving fits into your day.
- Sugar and calories per serving.
- Third-party testing, if the brand claims it.
Where Atlas fits
Each Atlas Strawberry Lemonade stick lists sodium 600 mg (26% DV), potassium 500 mg (11% DV), and magnesium 200 mg (48% DV) on its Supplement Facts label, with 0 g sugar. Check with your clinician before adding potassium or magnesium if you have kidney disease or take prescription medication.
See the label and ingredientsSources
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025.
- National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals.
- National Institutes of Health, Office of Dietary Supplements. Potassium: Fact Sheet for Health Professionals.
- National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Sodium and Potassium. 2019.
This article is for general education and is not medical advice. Talk with your clinician about your own needs. These statements have not been evaluated by the Food and Drug Administration. Atlas Hydration is not intended to diagnose, treat, cure, or prevent any disease.