Does drinking a whole bottle of water in 2 minutes give you the same hydration of drinking the bottle in 10 minutes?
Yes.
It gives you the same hydration if you drink it in two hours. The same *added *hydration, at least; what your body is doing with the water after you take it in can affect the net level, of course.
The whole topic comes with its own set of little woo-woo bells, and has since at least the 1980s.
In two minutes you’ll be more likely to urinate than before even the ten minutes. Would your body release the water you just drank, or would you absorb the most recent in take primarily?
See: mammalian biology. (It’s going to keep you busy a while.)
The idea that water in your stomach has some fast track to your urethra is… novel, at least. (Water has to go through your system - stomach, absorption into the bloodstream, filtering and extraction by the kidneys, accumulation in the bladder - before you can excrete it. Water you’ve just swallowed is at least many minutes from reaching your bladder, if not hours.)
When I down a pint of best bitter, I usually need to urinate fairly soon after. Am I correct that this is not the beer I just consumed but the urine that was already in my bladder. My guess is that there is a combination of psychological and physical pressure at work.
Yeah, but absorption in the kidneys is influenced by the blood pressure “detected” in the kidney’s efferent arterioles. If blood pressure is high (caused by drinking quickly?), the flow rate increases through the loop of Henle, resulting in lots of dilute urine.
Whether this will make a difference in 2-10 minutes, I don’t know. But the water in the stomach doesn’t have to end in the bladder to answer the OP’s question.