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Post by silverdragon on Sept 9, 2015 8:28:41 GMT
8 glasses of water a day, its rumoured that is what you should drink minimum...
So what is the science behind this?...
If you are thirsty, thats the body telling you you need to drink, so DRINK already.
In hot climates and low humidity, yeah, you may need more.
]But this 8 glasses doesnt ring true for everyone everywhere...
So where did it come from?... 'cos I for one cant find any reliable evidence to support this, and I certainly cant find any "science" to it.
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Post by GTCGreg on Sept 9, 2015 14:17:57 GMT
This came about many years ago when a researcher published a paper saying your body needed eight glasses of water to process the food you ate each day. Many people took this literally and insisted you needed to drink eight glasses of water a day. What they failed to realize, is that most of the water needed to digest the food is already in the food and no additional water is required.
Most reasonable doctors today concur that you have a built-in mechanism to let you know when you need water. It's called thirst. If you're thirsty, drink some water, if not, you probably don't need any more.
Just to be safe, I always drink at least eight glasses of water a day. My problem is, I always run it over some ground up coffee beans first. It's called caffeine addiction.
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Post by OziRiS on Sept 9, 2015 20:44:59 GMT
I read up on this a while back and it actually is a little more complicated than "drink when you're thirsty".
First off, thirst doesn't set in before you're already mildly dehydrated. This has been known for years and is taught to soldiers in basic training in most countries. As far as I can tell, it has at least been common practice since the beginning of WWII, possibly even earlier, and it's still taught today. I've personally found that, for me, if I exert myself physically and don't drink before I feel thirsty, a headache and sore neck muscles follow shortly after. It doesn't matter how much I drink at the moment I start feeling thirsty. It's already too late. Within 15 minutes, I'll have a headache as sure as the Earth orbits the Sun.
And that's the second thing. Your body is primarily made up of water. When you don't have enough of it, your body will start to conserve it for critical functions and the first thing to suffer is your skin. That's why the first thing you check when you suspect someone is dehydrated is skin elasticity on the back of the hand. As mentioned, headache is another good indicator of dehydration and, according to one study I found, up to 70% of all headaches could be avoided, simply by drinking a glass of water every two to three hours. This was tested in a temperate climate with people who weren't straining themselves physically. As soon as people start sweating, depending on how much you sweat, you could need as much as half a litre/one US quart per hour. In warmer climates, we're talking a litre/2 US quarts just to keep up with sweat production and another half litre/US quart to actually hydrate the body. When I was training to go to Iraq back in early 2008, we were told that when we were out and about for an entire day, consuming 14 litres/3.5 gallons of water in a day should be a goal to keep up with sweat production.
Another well known sign of dehydration is if your urine isn't clear. Any coloration at all should be considered a sign that you're not drinking enough. This goes back to water conservation. Keeping your muscles, brain, heart and lungs working is more vital to your short term survival than processing waste, so both your kidneys, your bladder and your bowels are cut off from getting any more water than they absolutely need to keep working and waste is stored for longer while your body reuses what little water it can extract from those organs for as long as it possibly can. Dark yellow or even orange urine is a sure sign that waste has been building up for a long time and. Being dehydrated for long periods of time can also lead to constipation for the exact same reason.
Chronic dehydration (being even mildly dehydrated for years at a time) - which for some odd reason is a diagnosis that isn't given nearly often enough* - is a condition that is well documented and can lead to chronic headaches, migraines, bowel obstruction, kidney problems (worst case = acute renal failure), various infections in the body and a lot of other nasty things. These things are in the more severe category, but it's also worth noting that people who have nice skin well into old age, have regular bowel movements and are hardly ever seriously ill have been found to drink at least 2 litres/half a gallon of clean water every day for most of their lives, according to some studies.
Now, I'm not the type to just take things at face value. I know as well as anyone here that many of these so-called "studies" are often... Let's call it "inspired" to come up with certain results, either because of confirmation bias, corporate sponsorships or any number of other reasons, so I did a little test of one claim I read.
DISCLAIMER: This is a little gross, so if you're squeamish about bodily functions, STOP READING NOW!
The claim was that drinking half a litre/a quart of cool water right after getting out of bed in the morning would get things going in your digestive system, encouraging bowel movement shortly after, which is a very healthy way to start your day. I've never in my life been "regular" with this. Sometimes I get up and I gotta go straight away, other times I can go a whole day without, so I thought I'd be the perfect test subject.
First day, I got up, went to the kitchen sink, filled a half litre glass with cool water and downed it. After just 5 minutes, I started feeling something moving around. After 10 minutes, it was getting more pronounced. After 15 minutes, I had to go.
Okay... One data point does not make science, so I kept at it for a month and sure enough, within 10-30 minutes of downing the water, I had to go. Worked every time.
Then I stopped. First day, I still had to go within an hour. Same the second day. Third day, it took more than 3 hours. That continued for a couple of days and then everything went back to "normal". Completely unpredictable. One day I'd go half an hour after getting up, others I could go until after dinner before something happened and I even had a stint of 3 whole days where nothing happened at all. This went on for another month.
First day I went back to downing the half litre of water right after getting up... Like freakin' clockwork! 15 minutes passed and I was in the John. I've been drinking that half litre of water every morning ever since.
*As for why chronic dehydration isn't diagnosed very often, ask your self this: How much money can the medical industry make off of you drinking water?
Push a pill and they make $5. Give you a glass of water and that's what? 5 cents? And those 5 cents don't even make it into their pockets.
Doesn't take a financial genius to see why not very many doctors will tell you, "All you need to do is drink more water."
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Post by GTCGreg on Sept 9, 2015 20:56:43 GMT
Not that sure that starting off your day with a good crap is all that beneficial, but if you say so, I'll take your word for it.
As for me, that's pretty much my normal routine. No water required.
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Post by OziRiS on Sept 9, 2015 21:13:09 GMT
Crap is waste. Stuff that your body has already determined it can't make use of. Getting that waste out of your body is never a bad thing. Keeping it in there can be if it stays there long enough.
Note that I'm not saying you can't be regular without drinking a quart of water every morning. I'm just saying it can help if you're not.
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Post by GTCGreg on Sept 9, 2015 21:30:33 GMT
Crap is waste. Stuff that your body has already determined it can't make use of. Getting that waste out of your body is never a bad thing. Keeping it in there can be if it stays there long enough. Note that I'm not saying you can't be regular without drinking a quart of water every morning. I'm just saying it can help if you're not. But what if your body isn't done processing it and you dump the load prematurely? Could be a waste of some perfectly good s--t. Just saying. I know, TMI. BTW, HERE''s a fairly recent article on the subject, (water, not poo) by a doctor. |
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Post by the light works on Sept 10, 2015 3:27:30 GMT
This came about many years ago when a researcher published a paper saying your body needed eight glasses of water to process the food you ate each day. Many people took this literally and insisted you needed to drink eight glasses of water a day. What they failed to realize, is that most of the water needed to digest the food is already in the food and no additional water is required. Most reasonable doctors today concur that you have a built-in mechanism to let you know when you need water. It's called thirst. If you're thirsty, drink some water, if not, you probably don't need any more. Just to be safe, I always drink at least eight glasses of water a day. My problem is, I always run it over some ground up coffee beans first. It's called caffeine addiction. the other thing to bear in mind is this is 8, 8 ounce servings of water. not 8 super big gulps. |
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Post by the light works on Sept 10, 2015 3:37:01 GMT
as for working in the heat, the advice I give people is, if you don't feel like you could pee if you wanted to, you need to drink more water.
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Post by GTCGreg on Sept 10, 2015 3:59:26 GMT
as for working in the heat, the advice I give people is, if you don't feel like you could pee if you wanted to, you need to drink more water. Is that from your EMT training? |
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Post by the light works on Sept 10, 2015 4:02:27 GMT
as for working in the heat, the advice I give people is, if you don't feel like you could pee if you wanted to, you need to drink more water. Is that from your EMT training? actually from fighting in the SCA. - predates my fire service training. |
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Post by OziRiS on Sept 10, 2015 5:56:06 GMT
as for working in the heat, the advice I give people is, if you don't feel like you could pee if you wanted to, you need to drink more water. Basically the same thing we were told in basic training. |
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Post by silverdragon on Sept 10, 2015 6:40:59 GMT
I watched something on TV at some point of some guy, and not the bear grills terp type, but some ordinary researcher, who spent some time with "special forces", who made a remark about every time they took a break, however short it was, the special forces has a camping stove out and were making a brew before he even got his pack off his shoulders....
Of course, UK special forces, they drink Tea like its going out of fashion.
I gather then that part of their training is drink before you get thirsty...
In my own experience, I have yet to see one "Special forces" off duty without a mug in his hand, unless its the ones on the way to the canteen....
In my own basic training, I was told drink plenty of water as often as you can because you never know when you will be without.
I also have training in Mountain rescue, and water was an essential part of the kit.
Knowing water points all over the place was good knowledge to have.
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Post by silverdragon on Sept 10, 2015 6:42:31 GMT
Question.
Does it HAVE to be plain water.
Tea Coffee, or diluted juice, does that count?..
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Post by OziRiS on Sept 10, 2015 6:58:34 GMT
Question. Does it HAVE to be plain water. Tea Coffee, or diluted juice, does that count?.. Any water counts, but if you're dehydrated, clean water has the advantage that the body doesn't have to seperate out impurities to make use of the fluid. This goes back to my thing about water conservation. If you're dehydrated, your kidneys and bowels take the back seat and other organs are prioritized. Any impurities in the water will not be filtered as effectively as they would be when you're not dehydrated, meaning that it takes longer for your body to process all the water in whatever it is you're drinking. Still, if plain, clean water isn't available, a cup of coffee, juice or whatever you can get at is still a heck of a lot better than nothing. As long as it's clean (free of harmful bacteria and metals). Of course, this also means that during the day, when you're NOT dehydrated, any water will do, so drinking tea, coffee and other things will keep you just as hydrated as drinking plain water. Just remember that you're building up a lot of waste from those things, so if you do get dehydrated, your kidneys will have a lot more to work with than if you'd just been drinking water all day. There's been a myth for years that caffeine will dehydrate you because it's a natural diuretic, so drinking coffe, cola and other caffeinated drinks when dehydrated will actually make it worse. Comprehensive studies have been done on this and it turns out that while it's true that caffeine is a natural diuretic, the average cup of coffee or bottle of cola has so little caffeine in it that you're more than capable of absorbing more of the water in the drink than you'll be losing. Many people still believe it though, so maybe that's what they should test...? |
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Post by silverdragon on Sept 10, 2015 7:54:12 GMT
Question. Does it HAVE to be plain water. Tea Coffee, or diluted juice, does that count?.. Any water counts, but if you're dehydrated, clean water has the advantage that the body doesn't have to seperate out impurities to make use of the fluid. This goes back to my thing about water conservation. If you're dehydrated, your kidneys and bowels take the back seat and other organs are prioritized. Any impurities in the water will not be filtered as effectively as they would be when you're not dehydrated, meaning that it takes longer for your body to process all the water in whatever it is you're drinking. Still, if plain, clean water isn't available, a cup of coffee, juice or whatever you can get at is still a heck of a lot better than nothing. As long as it's clean (free of harmful bacteria and metals). Of course, this also means that during the day, when you're NOT dehydrated, any water will do, so drinking tea, coffee and other things will keep you just as hydrated as drinking plain water. Just remember that you're building up a lot of waste from those things, so if you do get dehydrated, your kidneys will have a lot more to work with than if you'd just been drinking water all day. There's been a myth for years that caffeine will dehydrate you because it's a natural diuretic, so drinking coffe, cola and other caffeinated drinks when dehydrated will actually make it worse. Comprehensive studies have been done on this and it turns out that while it's true that caffeine is a natural diuretic, the average cup of coffee or bottle of cola has so little caffeine in it that you're more than capable of absorbing more of the water in the drink than you'll be losing. Many people still believe it though, so maybe that's what they should test...? Agreed, put drinking Water against Coffee/Tea and see what comes up?.... I suspect little to no difference at all until you start getting dehydrated. And if you are consuming enough fluids anyway, that wont be the problem will it?... |
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Post by OziRiS on Sept 10, 2015 8:11:26 GMT
For testing, I'm thinking take a baseline measurement of hydration levels for both Adam and Jamie and then have them exercise until measurements show they're dehydrated (not dangerously of course, but enough to take significant measurements). Test 1: Stop exercising when tests show dehydration, start drinking water. Measure hydration levels with regular intervals. Stop measuring once hydration levels are normal. Note how long it took to reach "normal". Test 2: Stop exercising when tests show dehydration, start drinking coffee. Measure hydration levels with regular intervals. Stop measuring once hydration levels are normal. Note how long it took to reach "normal". Possible test 3: Do the same, but substitute coffee for other types of caffeinated drinks to see if that makes a difference. Results: Are there any indications that caffeinated drinks make dehydration worse? Is there even any difference at all in how quickly you rehydrate? For the researchers: Here's a link for methods of testing hydration levels www.bchockey.net/Files/Best%20Practices%20for%20Clinical%20Hydration%20Measurement%202009-07-21.pdf |
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Post by silverdragon on Sept 10, 2015 8:20:42 GMT
Also, as raised on another thread, what effects do alcohol have when considering dehydration.
We KNOW it dehydrates already and leaves you minus Vit C, but...
If you are massively dehydrated and you get to a barrel of beer?... do you drink or look again?....
For me, its drink a pint or two as a temporary measure whilst I find something better if I was in that position.
Whilst on that score, if you are dehydrated, will Alcohol get you drunk quicker?...
Common belief is yes, when compared to a not dehydrated person.
Can this be tested?...
Who will go thirsty for a day and down a few pints and be tested against the next day when you drink as normal then down the same amount and do the same tests.
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Post by the light works on Sept 10, 2015 13:49:44 GMT
we have a board member who is a "water believer" who pitched a minor fit because one of our heavy rescues is equipped with a coffee maker and a fridge full of carbonated beverages. she yelled that that stuff shouldn't be on board because it dehydrates you.
my dad pointed out that some people simply will not drink unflavored water, and furthermore, sometimes people are cold or have low blood sugar instead of being dehydrated.
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Post by GTCGreg on Sept 10, 2015 14:09:41 GMT
we have a board member who is a "water believer" who pitched a minor fit because one of our heavy rescues is equipped with a coffee maker and a fridge full of carbonated beverages. she yelled that that stuff shouldn't be on board because it dehydrates you. my dad pointed out that some people simply will not drink unflavored water, and furthermore, sometimes people are cold or have low blood sugar instead of being dehydrated. And just why are you people forcing her to drink that stuff. |
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Post by the light works on Sept 10, 2015 14:17:36 GMT
we have a board member who is a "water believer" who pitched a minor fit because one of our heavy rescues is equipped with a coffee maker and a fridge full of carbonated beverages. she yelled that that stuff shouldn't be on board because it dehydrates you. my dad pointed out that some people simply will not drink unflavored water, and furthermore, sometimes people are cold or have low blood sugar instead of being dehydrated. And just why are you people forcing her to drink that stuff. we're not, she was trying to prevent US from drinking that stuff. |
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