Bottom line: If you did 45 minutes in an air conditioned gym, you needed water. That’s it. Electrolyte powder is a real tool for a specific situation, and that situation is sweating a lot for a long time. When you’re actually in it, LMNT has the sodium content that matters and skips the sugar. If you want something cheaper for everyday use, Liquid I.V. costs about half as much per stick.
1,000mg of sodium per stick and no sugar. Built for people who actually lose salt, which is the only reason to buy this stuff.
This category exploded because the marketing is brilliant and the science is real but narrow. Both things are true at once, and sorting them out saves you a lot of money.
What Sweat Actually Takes From You
Sweat isn’t just water. It’s water plus dissolved salt, mostly sodium, and the amount varies enormously between people. Some of us finish a run with white crust on a hat brim. Some of us never do. That’s a genuine physiological difference in sweat sodium concentration, not a difference in effort.
Here’s why it matters. If you sweat out water and salt, then replace only the water, the sodium left in your body is now spread thinner. Your blood sodium concentration drops. In extreme cases that’s hyponatremia, which is rare but genuinely dangerous and shows up in marathons and long hot events. In everyday cases it’s much less dramatic: you feel flat, maybe crampy, and drinking more water makes it slightly worse rather than better.
Now the part the ads skip. That whole mechanism requires meaningful sweat loss to kick in. A 45 minute lifting session indoors does not produce it. Neither does a normal day at a desk. Your kidneys are extremely good at holding onto sodium when you need it, and normal food contains plenty. For most sessions, most days, water and a normal diet cover it completely.
Our endurance training guide goes deeper on the timing side, and if you’re tracking training load, our recovery score guide is a better place to look for why you feel flat than a drink mix is.
The Number to Compare Is Sodium, and It Varies Wildly
Every brand in this category leads with a long ingredient list. Ignore most of it. Sodium is the electrolyte you lose in quantities that matter during exercise, and the spread between products is enormous. LMNT runs 1,000mg per stick. Liquid I.V. sits around 500mg. Nuun Sport is closer to 300mg. That’s a threefold difference in the thing you’re supposedly buying.
Potassium and magnesium show up on every label too, and they’re fine, but you lose far less of them in sweat and dietary intake usually covers it. Treat them as a bonus rather than a reason to choose. (Figures above are from each product’s manufacturer nutrition panel; the judgment about which mineral matters most is ours.)
Sugar is the other real variable. Liquid I.V. includes it deliberately, because glucose and sodium share a transport mechanism in the gut and pairing them speeds absorption. That’s the oral rehydration principle, it’s well established, and it’s genuinely useful when you need fluid in fast. It’s also 11 grams of sugar you might not want in an everyday drink. LMNT skips sugar entirely and absorbs a bit slower as a result. Neither approach is wrong, they’re just built for different moments.
LMNT: Best for Heavy Sweat and Long Efforts
LMNT Zero Sugar Electrolytes, around $45 for 30 sticks. 1,000mg sodium, no sugar.
LMNT went all in on sodium and it’s the right call for its audience. A gram of sodium per stick is a lot, and if you’re running long in heat or you’re one of those people whose shirt dries stiff, that’s the point. The taste is aggressively salty at first and most people either adjust in a week or dilute it in more water than the label suggests.
Who this is for: endurance athletes going past 90 minutes, anyone training in real heat, heavy or salty sweaters, and people eating low carb or keto. That last group is not a marketing gimmick. Lower carbohydrate intake reduces insulin, and lower insulin means your kidneys excrete more sodium, so keto dieters genuinely do lose more salt and often feel noticeably better replacing it. Skip it if your training is short, indoor, and you barely sweat, because you’d be paying $1.50 a day for salt you already get from food.
Liquid I.V.: Best for Everyday Use and Fast Absorption
Liquid I.V. Hydration Multiplier, around $24 for 16 sticks. Roughly 500mg sodium, includes sugar.
Liquid I.V. is the mainstream pick and it earns that on price and palatability. It tastes like a normal drink rather than saline, which sounds trivial but decides whether the box gets used or sits in a cupboard. The included glucose speeds fluid absorption through the sodium-glucose cotransport pathway, so this is the one to reach for when you need to rehydrate quickly.
Who this is for: people recovering from a hot day, travelers dealing with flight dehydration, anyone who found LMNT too salty to finish, and the classic hangover use case, which is real hydration science even if nobody wants to write it on the box. Also good for moderate exercisers who want something more than water without the endurance-athlete sodium load. Not the pick if you’re avoiding sugar or if you’re a genuinely heavy sweater, because 500mg won’t keep up.
Nuun Sport: Best Low-Sugar Everyday Tablet
Nuun Sport Electrolyte Tablets, around $50 for a multi-pack. Roughly 300mg sodium, about 1g sugar, tablet format.
Nuun is the lightest formulation here and the most convenient. Tablets drop into a bottle without the powder mess, they’re easy to carry, and the taste is mild enough to drink all day. The low sodium content is a real limitation for long efforts and a genuine advantage for everything else.
Who this is for: gym sessions, cycling commutes, hikes in mild weather, and anyone who wants flavor and a light mineral top-up without a sugar hit or a salt bomb. It’s also the friendliest option for people who just don’t like drinking plain water and will hydrate more if the bottle tastes like something. That’s a legitimate reason to buy it.
How We Evaluate
We don’t run sweat testing and we’re not going to imply otherwise. This comparison uses manufacturer nutrition panels for sodium, potassium, magnesium, and sugar content; the established physiology of sweat sodium loss and the sodium-glucose cotransport mechanism behind oral rehydration, which is what drives the expectations section above; and a large volume of long-term owner feedback, weighted toward reports from people using these across a full training season, because taste fatigue and stomach tolerance only show up with repetition. Nutrition figures are from the manufacturers. Which mineral matters most, and who actually needs supplementation, is our judgment and labelled as such.
Who Should Skip Electrolyte Powder Entirely
Most people, most days. If your training is under an hour, indoors, and you’re not dripping, water and normal meals handle it. Adding sodium you don’t need isn’t dangerous for a healthy person, but it’s an expensive habit built on a problem you don’t have.
Anyone managing high blood pressure or on a sodium restricted diet should talk to a doctor before adding a gram of salt per serving to their day. That’s not a boilerplate caution, it’s the actual concentration in some of these products.
Where they genuinely earn their place: long endurance sessions, hot weather training, heavy sweaters, low carb diets, and recovering from illness or a very rough night. That’s a real list, and if you’re on it these work. If you’re not, spend the money on something that changes your training instead, like the gear in our heart rate monitor guide or a weighted vest for your walks.
How to Tell If You Actually Need One
There’s a free test and it takes one workout. Wear a dark shirt for a hard session, let it dry, and look at it. White salt streaks mean you’re a salty sweater and electrolyte replacement is genuinely worth it for you. No streaks means your sweat sodium is on the lower end and water is probably fine.
The other signal is cramping that shows up late in long sessions, especially in heat. Cramp causes are debated and it isn’t purely a sodium issue, but heavy sweaters who cramp late often report real improvement from replacing salt. Worth trying before you spend money on anything fancier.
If you want to get precise about it, weigh yourself before and after a long session. Every pound lost is roughly 16 ounces of fluid, and if you’re routinely dropping two or three pounds in an hour you’re sweating enough to care about what’s in it. That’s the same kind of self-measurement our 5K training guide and running watch roundup lean on, and it beats guessing.
FAQ
Do you actually need electrolyte powder?
Only in specific situations. Sessions over 60 to 90 minutes, hot conditions, heavy sweating, or a low carbohydrate diet all increase sodium loss enough to matter. Short indoor workouts with normal meals do not, and water is the correct answer there.
Which electrolyte matters most in sweat?
Sodium, by a wide margin. It’s lost in the largest quantities and it’s the one that affects fluid balance. Potassium and magnesium appear on every label but are lost in much smaller amounts, and typical diets usually cover them.
Why does Liquid I.V. have sugar when LMNT does not?
Glucose and sodium share a transport pathway in the small intestine, so including sugar speeds fluid absorption. That’s the oral rehydration principle. LMNT prioritises zero sugar and accepts slightly slower absorption. Different design goals, both defensible.
Can you drink too much electrolyte powder?
A healthy person will typically excrete the excess, but a gram of sodium per serving adds up fast if you’re using several a day. Anyone with high blood pressure or a sodium restricted diet should check with a doctor first.
Do electrolytes help with hangovers?
Partly, and the mechanism is real. Alcohol increases fluid and sodium loss, so replacing both helps more than water alone. It won’t undo the rest of what alcohol does to your sleep and your liver, which is where most of the misery actually comes from.