What is an electrolyte anyway?

I was standing in a convenience store trying to find the Red Bull (because every once and a while I like to enjoy a useless heavily caffeinated cold beverage, and its cheaper than a Starbucks frappawhataever) and found myself staring at the Gatorade. Gatorade, it claims, restores valuable electrolytes after exercise. That sounds pretty important.

Does anyone know what an electrolyte is?

I didn't, so I decided to use the net to find out. I ended up at Wiki, because that's usually a pretty decent source of generic information like this. Here's what I found (and you can see the page here)

Electrolytes are commonly found in sports drinks. In oral rehydration therapy, electrolyte drinks containing sodium and potassium salts are used to replenish the body's water and electrolyte levels after dehydration caused by exercise, diaphoresis, diarrhea, vomiting or starvation. Giving pure water to such a person is not the best way to restore fluid levels because it dilutes the salts inside the body's cells and interferes with their chemical functions. This can lead to water intoxication.

So electrolytes are sodium and potassium salts (with some other elements mixed in). Like...in a banana? Anyway, replacing these electrolytes only seems to be important after you are dehydrated. In other words, Gatorade, which replaces electrolytes and is commonly used while exercising, is completely useless when compared to plain water because it doesn't matter if you are replacing electrolytes unless you are severely dehydrated.

Good to know.