You need both, and lose both in any athletic activity. (lose other stuff too, btw). They don't work against each other, they work as a pair.

So I include both... Basically, things I salt (like eggs) I use KCl; and then favor salty foods like salted nuts, bacon. Seems to work ok. I kinda use my BP as a salt meter; if its around 120sys I'm good, when it goes high I might have overdone the salt, if it goes low when standing up I undershot.