So, another thing I realize is that people do not understand why "drinking too much" is actually a danger. And mind you, I am not a nephrologist or cardiologist. I just got screamed at by a cardiologist for having drunken too much once.
So, basically there is two aspects to "drinking too much". One is that, indeed, you can drink so much that your kidneys cannot keep up with it. And what happens in that case is that basically a bunch of important osmosis stuff in your body gets unbalanced because it is diluted too much, and that is bad. Though admittedly: if you are a healthy adult, it is indeed quite hard to drink too much. It is possible. But under normal conditions it is very hard.
The bigger danger is exercise associated hyponatremia.
For this you gotta understand a big thing about exercise: when you exercise and use your muscles and everything, your body basically enters exercise mode. Which means it knows you will expend a bunch of energy, and also will likely heat up a bit, meaning that your body knows it will have to cool you down. So it basically says: "for the moment sweating is our priority". Which also means that it kinda lowers the energy put into the kidneys for the moment, because you need that water to sweat.
Only that... this obviously means the water does not get excreted as much. And due to the misinformation largely spread by gatorade as part of their marketing campaign, people often drink too much while working out, creating hyponatremia.
As you might notice: hyponatremia means you are low on sodium (natrium). But is not because you did not take enough sodium in many cases, but because you took in too much water. In almost all hyponatremia cases in healthy adults it is due to them drinking too much while working out and their electrolytes becoming unbalanced. And yes, that even happens when you drink the sports drinks that usually put sodium into your system.
They did a study on several marathons. And in many cases 20-30% of the runners were hyponatremic due to having ingested too much fluids.
So, yes. You can drink too much.
I really cannot stress it enough: drink when you are thirsty. If you drink when you are thirsty until you are not thirsty anymore, then you have drunken enough. With, again, the caveat obviously being that is you are on somehow disregulating medications (which can include a bunch of psychoactive medications) that might shift your sense of thirst, hunger, and other base instincts.
And yes, this also means this "this is the right amount to drink" stuff is... unreliable at best. If you actually look into the research into the topic of "how much should someone drink", you will often find a citation chain that goes like this "this study got it from that study, and that study got it from this 70s study, and the 70s study got it from this 50s study, and that 50s studies got it from some military medic in WWII who just claimed that was the right amount to drink with no citation given". Generally medicine is somewhat certain that those "you need to drink at least 3 liters a day" things are not true. It might be true for some people, but not for the vast majority of people. If your body is working normally, you know when you are thirsty. Just listen to your body. Your body is a very finely calibrated instrument. Make sure you have access to safe drinks all the time if you can, and drink when you are thirsty. I swear to you, you will be fine.
