http://www.guardian.co.uk/lifeandstyle/ ... -water-day

The amount of people I know personally who buy into that...

I thought it was 8 glasses of Coke a day.

Addict!

Could probably say something about the cola habits of people they know.

And they do, as they sit there with their dull-ass over-priced water

Yes we don't all need 8 glasses of water, but we do need some.

I've always advised patients to drink enough so their urine is a pale straw colour. If it's dark, drink more. If it's virtually clear, drink less. Thirst is a poor indicator of the level of hydration, mainly inthe young and old.

Tap water is fine and you don't need to lug huge bottles of water when you go to the gym. I used to take a small 500ml bottle and even then I'd drink at the most 400mls (normally only 250mls) - even to moisten the mouth and tongue.

Some animals are different and are designed to cope with extremes of climate, managing to live days wothout drinking and relying on the metabolic water produced by breakdown of things like fat during metabolic respiration.

I remember when I was out in the wilds of Uzbekistan, the advice given was not to drink loads of water - just swill enough around your mouth to keep it moist. I’m not sure about the reasoning about this, but I assume it’s something to do with keeping the right amount of water in the body, rather than force it to deal with an excess.

That works much better if you read it imagining it's being spoken by Rowley Birkin QC...

Well, yes.

In say a desert environment, you'll lose salts as well as water. Typically, water is replaced by drinking but not the salts. Which can cause derangement of blood chemistry, leading to problems.

Also, if you do drink your urine, do so only once. Subsequent attempts will reshlt in the kidneys having to work harder as they have to deal with more and more concentrated urine.

I find while I work, especially in an air conditioned office (not now typically as it's packed in since the power cut the other day) I drink more than that over the course of a day, but I find when I get thirsty I get headaches and that includes cola, tea, fruit juice etc

By the time most of us are thirsty, hydration levels have already dropped - not a dangerous amount and I cannot recall the figure but it's enough to cause things like headaches. I get them too, especially when on-call since this is when I'm mentally and physically exerting myself with long hours and running all over the hospital.

Doesn't airconditioning have a dehydrating effect by drawing moisture from the air so more is lost from our respiratory system?

Yep, it's why my gf can't wear her contacts at work because her eyes get too dried out, so she has to wear special safety specs* instead of the normal ones


*that make her look stupid

I get dehydrated very easily, especially if it's warm. Even as a child I had to drink 2 litres every 4 hours if I was exercising in the sun to avoid chronic fatigue and head aches. I generally get through about 2 litres of water just while I'm at work.

In the winter, if I'm not doing ought and the heating isn't set to "Vulcan" then I only need about 500ml a day...

I thought this was pretty old news - the original research said that we needed about 8 glasses, or ~1 litre, of water a day including water gained from food intake. That second bit was left out when the story was propagated.