Edit: Question answered. Thanks!
Don’t be too hard on me, I almost failed chemistry:'(
In: 2220
Everything is toxic if you take too much or too little of it.
In the case of electrolytes, it moderates the electrical nervous signals in your body.
Too little, signals cannot reach the body parts which is dangerous.
Too much, irregular signals will be sent throughout the body causing arrhythmia or other dangerous conditions.
Seawater is much saltier than electrolyte solutions.
Seawater is about 3.5% salt. Your body tissues are about 0.9%. Your kidneys can concentrate your urine to more than 0.9%, but not to 3.5%, meaning that your urine is always removing less salt-per-water than seawater. If your kidneys work as hard as they can, they can manage about 2%. That means that, to clear the salt from 1 liter of seawater, you need ~1.75 L of water in your urine. +1 L of seawater, -1.75 L of urine equals -0.75 L of water overall.
A 20 oz bottle of Gatorade contains 270 mg of sodium. That’s an implied content of about 681 mg of salt. 20 oz of water is about 600 mL, or about 600 g of water, meaning that Gatorate’s salinity is about 0.1%. That’s less than your body tissues, and far less than seawater.
A saline solution pumped in by IV at the hospital is typically *isotonic* – equal to your body’s natural ~0.9% salinity – and would taste very salty if you tried to drink it.
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EDIT: a point that has come up in some of the comments here is that, because your body absorbs water by osmosis, you can’t actually absorb water from a 3.5% saline solution at all. This is true: seawater in your gut will simply pull water *out* of your body osmotically, and in fact laxatives usually work on this exact principle.
That said, adding 1 L of seawater to 10 L of fresh water would result in a mixture your body can absorb, but which would result in less hydration than just drinking 10 L of fresh water would, for the reasons described above.
> Aren’t they both water + salts?
Yes, but VERY different amount of salts. The sports drink has a pretty low salt concentration. Just enough to replenish the salt lost by your body by sweating. Sea water contains many times more salt per volume, and is much saltier than your body itself. It’s so salty that when you drink it, your body has to use up its *existing* water trying to dilute the salt enough to pee it out before it kills you by frying your nerves (nerves use salt to send signals, so getting flooded with salt messes them up).
It comes back to the classic saying “**the dose makes the poison**”, which just means “anything is toxic if you consume enough of it”. Heck, even plain water by itself is toxic if you drink too much. Eating some salt on your pasta is fine. Eating a pound of salt out of the bag is not. Seawater is much like option 2 there. **Only about 13L (3.5 gal) of seawater contains a** ***pound*** **of salt.** That’s only a few days’ worth of water-drinking. Imagine eating a pound of salt in a couple days. That’s why seawater isn’t drinkable.
> Aren’t they both water + salts?
Yes, but VERY different amount of salts. The sports drink has a pretty low salt concentration. Just enough to replenish the salt lost by your body by sweating. Sea water contains many times more salt per volume, and is much saltier than your body itself. It’s so salty that when you drink it, your body has to use up its *existing* water trying to dilute the salt enough to pee it out before it kills you by frying your nerves (nerves use salt to send signals, so getting flooded with salt messes them up).
It comes back to the classic saying “**the dose makes the poison**”, which just means “anything is toxic if you consume enough of it”. Heck, even plain water by itself is toxic if you drink too much. Eating some salt on your pasta is fine. Eating a pound of salt out of the bag is not. Seawater is much like option 2 there. **Only about 13L (3.5 gal) of seawater contains a** ***pound*** **of salt.** That’s only a few days’ worth of water-drinking. Imagine eating a pound of salt in a couple days. That’s why seawater isn’t drinkable.
> Aren’t they both water + salts?
Yes, but VERY different amount of salts. The sports drink has a pretty low salt concentration. Just enough to replenish the salt lost by your body by sweating. Sea water contains many times more salt per volume, and is much saltier than your body itself. It’s so salty that when you drink it, your body has to use up its *existing* water trying to dilute the salt enough to pee it out before it kills you by frying your nerves (nerves use salt to send signals, so getting flooded with salt messes them up).
It comes back to the classic saying “**the dose makes the poison**”, which just means “anything is toxic if you consume enough of it”. Heck, even plain water by itself is toxic if you drink too much. Eating some salt on your pasta is fine. Eating a pound of salt out of the bag is not. Seawater is much like option 2 there. **Only about 13L (3.5 gal) of seawater contains a** ***pound*** **of salt.** That’s only a few days’ worth of water-drinking. Imagine eating a pound of salt in a couple days. That’s why seawater isn’t drinkable.
That much salt can kill you, so your body has to push it out, but to push it out your body needs more water than you drank to do it.
So to keep yourself from getting sick from the salt water, you pee out more water than you drank. So after you drink salt water you need more water than you did before. That’s bad.
That much salt can kill you, so your body has to push it out, but to push it out your body needs more water than you drank to do it.
So to keep yourself from getting sick from the salt water, you pee out more water than you drank. So after you drink salt water you need more water than you did before. That’s bad.
If your kidneys could produce a sufficiently concentrated urine to “steal” H2O from seawater, you could drink seawater and hydrate yourself with it. A small australian mouse can do that (crazy kidneys). You, as a human, can’t. You are effectively introducing a sodium load so large that your body will need to GIVE WATER TO IT in order to expel it. That’s why you dehydrate yourself really fast if you drink seawater.
All the answers here are missing a vital component. The biggest issue is that water follows the salt. Salt is the leader in this situation. In a balanced world there is as much salt in your cells as outside and everyone is happy. The leaders all agree to be balanced and the cells are healthy. Each portion of salt attracts the same amount of water, each leader has the same number of followers.
Electrolyte solutions keep this healthy balance so the leaders inside and outside the cells agree that the right amount of water is where it is supposed to be.
If you drink a lot of sea water you are introducing too many leaders (salt). They can’t go into the cells like the water can. (Cells have walls to keep the balance.) The extra leaders call all the water out of the cells and the cells shrivel (called crenation). If they shrivel too much they die.
If you drink too much water the leaders in the cells will expand and cause them to pop, also creating cell death.
That much salt can kill you, so your body has to push it out, but to push it out your body needs more water than you drank to do it.
So to keep yourself from getting sick from the salt water, you pee out more water than you drank. So after you drink salt water you need more water than you did before. That’s bad.
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