noagname said:
ok,
this is a couple of questions in one
where is water stored in your body?
i know some is stored in your blood stream, but then does it ever get emptied out
and if it does then why are some athletes not allowed to drink a lot of water
i heard that they will get to much water in there blood
how do you sweat and while you are sick does it help to sweat?
Your kidneys control the overall amount of water and salt in your body (homeostasis). Typically, our bodily fluids are at around 320 mOsm, but there is a huge difference between the solution inside a cell (120 mOsm potassium, 5 mOsm sodium) and outside a cell (120 mOsm sodium, 5 mOsm potassium). This difference is used by every cell to "do" things: muscle contraction, nerve impulses, etc. etc. There's another ~50 mOsm of cloride, ~30 mOsm of bicarbonate, ~5 mOsm of calcium (extracellular), and so on.
Sweat is mostly Na, Cl and water. During normal perspiration, the salt is re-absorbed by the epithelial layer, with the overall result of slow loss of water- drinking plain water is sufficient to maintain homeostasis. During extreme perspiration, there is both loss of salt and water, requiring replacement of salt as well. That is, simply drinking salty water is best for heatstroke and the like.
Gatorade and the like do more than simply replace salt and water. "sports drinks" are a combination of salt, water, and glucose. The glucose is there (in theory) to replenish depleted energy stores within muscles which occurs during excersise. The gut and renal epithelia couples glucose and salt uptake for a couple of reasons. Drinking salty sugar water will allow faster absorption of the sugar than drinking plain sugar water.
It's possible to overdose on distilled water (never drink deionized water!) by washing out the osmotic gradient present in the kidney, required for urine concentration (countercurrent hypothesis). It's possible to overdose on anything! Drinking sufficient quantities of gatorade, fast enough, will also result in damage- I'm not sure what the mechanism is, but all that stuff has to go somewhere.
Sweating is part of the excretion mechanism and relates to maintenance of core body temperature. I don't think "sweating out a cold" works because of any immunological benefit- what is excreted is salty water, not bacteria or viruses. Cystic Fibrosis patients have a higher osmotic concentration in their sweat than normal.