Electrolytes: What are they and do you need to supplement them?

Electrolyte drinks like LMNT, Liquid IV, Nuun, Ultima and more are everywhere! But what is an electrolyte? Do you need to be adding an electrolyte drink to your diet? And how can you optimize your eating so that you're getting those nutrients from your food? Some people will find that they could benefit from supplementing with an electrolyte drink or sports beverage, especially during a hard workout, and definitely when you are sick.