Electrolytes: Do You Actually Need Them?

Electrolyte powders made the jump from the endurance-sport aisle to the kitchen counter, and plenty of people now start the day with a $1-2 stick out of habit. The marketing leans on a half-truth: electrolytes are essential, therefore supplementing them must be good. Essential they are. But 'essential' and 'you're short on them' are different claims — and for most people, most days, the second one isn't true.

What electrolytes actually do

Electrolytes are minerals that carry an electrical charge — sodium, potassium, chloride, magnesium, calcium. They run nerve signals, muscle contractions, and fluid balance. Sodium is the headline act for exercise: it's the mineral you lose most of in sweat, and it's what lets your body hold on to the water you drink rather than pass it straight through. That's the real job of an electrolyte drink — not 'hydration' in the abstract, but helping fluid stay where it's useful when you're losing a lot of it.

Your diet is already an electrolyte supplement

The average Western diet delivers well over 3,000 mg of sodium a day — more than most guidelines want, before you add a single stick. Potassium comes from fruit, vegetables, potatoes, and dairy; magnesium from nuts, greens, and whole grains. If you eat normally and aren't sweating buckets, your electrolyte 'deficit' after a regular workout is usually rounding error. A glass of water and your next meal replace it without ceremony.

When they genuinely help

There's a real audience for electrolytes, and if you're in it they matter a lot: sessions over about an hour, especially in heat; endurance athletes; heavy or 'salty' sweaters; and people losing fluid to illness. The ACSM position stand on fluid replacement recommends adding sodium to fluids during prolonged exercise precisely because sweat sodium losses add up and plain water alone can fall short. The dividing line isn't 'athlete vs not' — it's how long, how hot, and how much you sweat.

The risk nobody sells you: overdrinking

The failure mode of the 'drink more' era isn't dehydration — it's the opposite. Exercise-associated hyponatremia happens when you drink so much plain water that blood sodium drops below 135 mmol/L, and in severe cases it's fatal. It has killed marathon runners who diligently hydrated on a schedule. This is the strongest argument for two things: drinking to thirst rather than by the clock, and including sodium — not just water — when you are going long. If you want to sanity-check your own numbers, our hydration and electrolyte calculator estimates both your daily water target and whether a given session actually calls for sodium.

How much sodium to replace

When you do need it, aim for roughly 500-700 mg of sodium per litre of fluid on long efforts, scaling up if you're a heavy salty sweater. That's a guide, not a prescription — individual sweat sodium ranges from about 200 to over 2,000 mg per litre, a tenfold spread. The practical test costs nothing: if your skin is gritty, your eyes sting, and your black kit dries with white salt lines, you're at the high end and should replace more. If not, you almost certainly need less than the marketing implies.

What to look for if you buy one

Skip anything sold on 'more electrolytes = better'. For endurance use you want a meaningful sodium dose — often 300-1,000 mg per serving — not a token 50 mg dusted over a sugar-free flavour. Watch the sugar too: a little glucose speeds sodium and water absorption on long efforts, but a daily sugary stick you don't need is just soda with a health halo. For everyday hydration, the honest answer is the cheapest one: water, and eat your normal food.