Eli5: Why does sea water kill us but electrolyte solutions actually hydrate us? Aren’t they both water + salts?

Question

Edit: Question answered. Thanks!

Don’t be too hard on me, I almost failed chemistry:'(

In: 2220

Answer 1

Electrolyte solutions don’t hydrate you better than pure water, the point of them is that if you only add water back to your body during physical activity your not replenishing other critical compounds that are lost or used up during says activity. Electrolyte solutions replenish those in addition to hydrating you.