You get your electrolytes from your food.

I drink water when hiking. I also make sure I have salty and electrolyte rich snacks with me and that I am eating the same
along with drinking water.

3 days hiking for me usually ends up with large salt crusties on my shirt and hat - ample evidence that I'm kicking out lots
of salt and other goodies in my sweat. (and time to jump in a creek/lake and wash up so I'm not so funky)