I know gator-aid and its like advertise that they have lots of them. And I know sometimes I feel bad if I sweat a lot and just drink water. But are they just advertising... salt? Are there different kinds of electrolytes, and if so are they interchangable?
Effectively, yes. "Electrolytes" is a collective term for the ions that help move stuff into and out of your cells. These are primarily sodium and potassium, although calcium also plays a role. Sodium is the most important of these for sports drinks, because it is the one you most lose through sweat.
Unfortunately, most sports drinks don't really contain enough to balance out heavy sweating, because sodium salt (aka normal salt) tastes, unsurprisingly, salty. If a drink had the right balance of sodium, it would be noticeably salty. Gatorade has one line of drinks that do that, and Pedialyte is specially made for the correct balance. Sports drinks really jack up the sugar to help hide the salt taste.
Most sports drinks, rather than having the sodium you need to replace sweat, instead jack up the potassium (think Prime and it's advertised 843mg of electrolytes, 700mg of which is potassium). This doesn't really replace the electrolytes you need, but it also doesn't make the drink nearly as salty.
When you see "electrolytes", you should flip around to the nutrition label, which must list the actual amounts of sodium and potassium. This will tell you if it will actually help you recover from activity, or if it's just more sugar water and advertising.
Edited to add:
why is sodium so important? Because your cells use a mechanism called "osmosis" to move water back and forth. Water molecules naturally move from areas of high concentration to areas of lower concentration. In the cell, this means that water will go in to the cell if the inside of the cell has more sodium than the outside, and leave the cell when the outside has more than the inside.
When you sweat, two things happen: you lose water and you lose sodium you lose more water than sodium, so your blood becomes saltier. Water moves from inside your cells to your blood; this is what it means to be "dehydrated". To counter it, you need to dilute your blood and increase the amount of sodium in your cells. Hence, drinking water with sodium can help replenish both and speed recovery from dehydration.
Sodium is also used for all the electrical activity of our body (such as thinking and moving and living...), and is fundamental in adsorption of nutritions in digestion. Sodium, potassium and calcium are so important that it is difficult to even list all processes they are involved.
Edit. To add context our cells spend between 30 and 70 % of their energy to move around sodium and potassium ions https://en.m.wikipedia.org/wiki/Sodium–potassium_pump
A good chunk of what we eat is to move them around
Yup, they are the basic electron donators for almost everything. In the context of sports drinks tho, hyponatremia is the #2 threat (after hypernayremia, funnily enough), so the rest of it was sort of overcomplicating
They don't donate electrons. When metallic sodium or potassium donate electrons they burn, explosively. It doesn't happen in our bodies. It happens by simple contact with water.
They are already in their ionic form in our body. They cross membranes as ions, creating a potential difference across the membranes. Allowing ions to diffuse along the gradient generates the electric signals of our brains, or triggers the muscle contraction, among other things
This is quite true. The only people who need to worry about this on the regular are endurance athletes (and people with equivalent jobs). Anything where you are working at an elevated heart rate and sweating for hours or days. Not common for joggers or people who shoot hoops after work
I actually take electrolyte tablets with me when I hike. Hyponatremia (having dangerously low salt levels) can really sneak up on you when you are hiking in the heat for four or five days straight. You keep hydrated, but there just isn't enough salt in your food to replace what you lose. Dropping a straight tablet of salt can really help balance that
Also this explains why after I have a particularly hard day at work, the thing that makes me feel the most regulated is a piece of steak that's very heavily salted.
I buy this and add it to my water. Use a little less than a 'serving' first time at it can activate your gut - maybe from the magnesium? Buying it by the bag makes it much much cheaper than liquid iv.
Since what you really need to replace is sodium, you could just make salt water. But there are a lot of products that make it easier
My preferred are Salt Stick caps... It's a tablet so you don't need to taste it at all
Back in high school I had some friends tour an NFL stadium. They got to see the field and locker rooms and all. I didn't get to go with them, so while they were in the locker rooms they stole a bunch of these powdered electrolyte drinks they had out for the players and brought some back for me. I remeber trying them and they tasted like straight sweat. It makes sense, but they were gross. Same flavor as licking someone's forehead.
You could buy ORS (oral rehydration salt) from a pharmacy and mix it in water. Make sure the packet follows the WHO formula, and that you add the correct amount of water. If these are not available, the WHO recommends 3 g salt and 18 g sugar per litre (roughly 1 teaspoon and 6 teaspoons per litre) of water. But this will not have potassium and other minerals.
Well, during heavy excercise, a lot more than salt is lost. Another thing lost is blood glucose. It can help you recover to replece the glucose as well, so the sugar in sports drinks can be useful as well.