For most easy, everyday activity, plain water is enough. Your body holds a reserve of electrolytes, and a light walk or a short workout does not move the needle much. The picture changes once you sweat hard.
When does water stop being enough?
Sweat is not just water. It carries sodium, plus smaller amounts of potassium, magnesium, and chloride. Sweat can hold anywhere from about 200 to over 1,800mg of sodium per liter, so on a long, hot, or hard session you can lose a meaningful amount. Replace that loss with plain water alone and you dilute the sodium you have left, which is when people feel flat, headachy, or still thirsty even after drinking plenty.
A simple rule of thumb: under about an hour of easy effort, water usually covers it. Past an hour of hard sweat, in heat, or if you sweat heavily, you have likely lost enough sodium that water alone leaves a gap.
How do I know I have crossed that line?
Common signs you have lost more than water can replace:
- You keep drinking but stay thirsty.
- You feel flat, foggy, or headachy after a sweaty session.
- Your sweat stings your eyes or leaves white salt marks on your kit.
- You get muscle twinges late in a long effort.
If you want a number instead of a guess, our sweat sodium loss calculator estimates how much sodium you lose based on your sweat rate, then translates it into servings.
What does an electrolyte serving actually replace?
One serving of Saltivate puts back 800mg sodium, 240mg potassium, and 60mg magnesium, with zero sugar. Sodium is the one you lose the most of, and it is what lets the water you drink actually stick instead of running straight through you.
You do not need it every time you reach for a glass of water. You need it when you have sweated hard, in heat, on a long session, or on a low-carb or fasting day when your body sheds extra sodium.
If you are not sure where you land, start with the sweat calculator, or browse the full range to pick a flavor or the unflavored mix.
