Water

[Tannhauser]

Fact or Fiction? You Must Drink 8 Glasses of Water Daily: Scientific American

Advocates of the 8 x 8 [eight glasses of eight ouncesof water a day] guideline sometimes claim that thirst is a poor hydration indicator. They assert that many people are so chronically dehydrated they no longer recognize their bodies' signals for water. Barbara Rolls, professor of nutrition sciences at the Pennsylvania State University, disagrees. Her studies, she says, "found no evidence that people are chronically dehydrated." Although some drugs can cause problems with thirst regulation and the elderly may not experience thirst as intensely as younger people, Rolls maintains that most healthy people are adequately hydrated.

Weight loss is another benefit often touted by proponents of the 8 x 8 guideline. They claim people mistake thirst for hunger, which causes them to eat when they are really just thirsty. They also allege that drinking water suppresses appetite. Given the obesity crisis, every little bit (or drop) helps.

But Rolls disagrees, arguing that "drinking water and waiting for pounds to melt away does not work. We all wish it were that simple." She explains that "hunger and thirst are controlled by separate systems in the body. People are unlikely to mistake thirst for hunger." Furthermore, she reports that her studies "never found that drinking water with or before a meal affected appetite." Nevertheless, there are some elements of truth in the misperception. Rolls did find that water-rich foods—as opposed to stand-alone water—tended to help people consume fewer calories. And, she says, "there is a way that water can help with weight loss—if you use water as a substitute for a caloric beverage."

[5kgLifter]

There was a program on TV about a year back in which a pair of twins were studied for one solid week. Before the study, they both drank 500ml of water a day, no other drinks at all.

During the study, one of the twins was to consume 8 glasses of water a day (2 UK litres, I assume, since I can't remember the exact size of the glasses) whilst the other twin remained on their normal 500ml.

Prior to and at the end of the study, measurements were taken concerning hydration of skin, hair (I think), skin elasticity, and a host of other fluid related readings; there was no difference in the repsonse of either twins' body at the end of the study and the twin that was drinking more did not have any higher a hydration level in the skin than the twin that was on her normal 500ml of water a day.

[RobMoriRB]

If you work out everyday, all you need is about a L of water per 50 lbs so if your 250 that is approx. G of water

[big valsalva]

Originally Posted by Tannhauser

With respect, I couldn't disagree more. I have indeed thought about the second part of the statement and have been arguing about the water consumption myth for some years. I've done so on MAB before.

For my money, it's one of the more pernicious bits of nonsense that has slipped - largely unchallenged - into the health industry. It began with the wonderfully named Dr. Batmanghelidj, who must have some sort of record for the number of people he has successfully made paranoid about something they have absolutely no need to think about.

Certainly, under some circumstances, it might be possible to outstrip the thirst trigger. It would be prudent to keep your fluid intake up, for example, if you're walking any distance in the heat or working construction. But for most people in temperate climates, who aren't being fantastically active, their usual drinking patterns are going to be plenty to satisfy their needs. I suggest that anyone who is worried keeps an eye on the colour of their urine. If it's orange or brown, maybe it's time to drink something. Other than that, stop worrying: thirst isn't like the oil light on your car (you know, by the time it's on, the damage is done).

There's absolutely no evidence that healthy people need to hit some sort of arbitrary target for water consumption. Homeostatic mechanisms are a physiological marvel, and cope incredibly well at conserving water. Someone in temperate climates stands more chance of overwhelming these by over-consumption.

As a bit of weak-sauce anecdotal evidence, I sip water in the gym -because I sweat buckets - and on a work day, I drink 5-6 cups of tea/milk. That's it. I've never had any symptoms that I could reasonably attribute to dehydration.

P.S. It's another myth that tea and coffee dehydrate more than they dehydrate.

P.P.S. Just because the body is composed of 60% water - or whatever it is - doesn't mean that you need to think about topping it up more. By that logic, we would need to ensure we're breathing x number of times a day, as we're composed of 65% oxygen atoms (by mass).

Touche!

All right then. We'll just disagree about this and move on, rather than start something. I maintain that there is no harm in staying hydrated whether by the 8x8 or some other method. I did think you brought up a very good point about urine color though. Something I forgot to mention.

[Tannhauser]

Just an update on this thread. There was a program on a few days in the UK called 'Panorama: The truth about sports supplements'. Unfortunately, I don't think you can view this outside the UK, or at least I can't find a link for it. Anyway, a generally interesting program looking at evidence for sports shoes, BCAAs, rehydration drinks etc.

One of the things they looked at was the obsession with hydration. These were the conclusions from the top-echelon researchers:

1. No one knows where this 2% dehydration results in x% performance loss idea comes from.
2. Over years of monitoring marathon events, there have been zero deaths that could reasonably be attributed to dehydration. There have, however, been 16 (from memory) attributed to over-hydration caused by drinking too much water. There have been 1600 incidents of severe illness (again, from memory) caused by over-hydration.
3. One of the factors contributing to this has been the belief that we need to take action before thirst strikes. This is a message heavily promoted by sports drinks manufacturers, but again there's no evidence that this is the case.

Most interestingly, they showed the South African army, who are carrying 60kg (132lb) packs in searing heat for hours at a time. The army carried out its own research into hydration...as a result of this, now the soldiers are not told they have to drink x amount. Their instruction is just 'drink when you feel thirsty'.

The sports shoe stuff was fascinating too.

[Transformed]

Drinking water will help make you feel fuller so you dont eat as much, and that will make you lose the weight.

[moeheep]

I lost 100 pounds in 6 months, during that time I drank over 1 gallon every day. Did that have anything to do with the weight loss? I have no idea....I am not saying it helps, I am not saying it doesn't. Just stating a fact. I guess just being no committal and taking up space on this thread.......

[5kgLifter]

Originally Posted by Tannhauser

Just an update on this thread. There was a program on a few days in the UK called 'Panorama: The truth about sports supplements'. Unfortunately, I don't think you can view this outside the UK, or at least I can't find a link for it. Anyway, a generally interesting program looking at evidence for sports shoes, BCAAs, rehydration drinks etc.

One of the things they looked at was the obsession with hydration. These were the conclusions from the top-echelon researchers:

1. No one knows where this 2% dehydration results in x% performance loss idea comes from.

Interesting, I automatically assumed that it was some scientifically approved fact given the amount of publications it's found in, which is pretty much every book relating to health.


2. Over years of monitoring marathon events, there have been zero deaths that could reasonably be attributed to dehydration. There have, however, been 16 (from memory) attributed to over-hydration caused by drinking too much water. There have been 1600 incidents of severe illness (again, from memory) caused by over-hydration.

Over-hydration can also cause people to stop peeing which then appears to the unwary that the individual is not hydrated enough and so they take on even more water; there is a name for it but I cannot remember what it is but once a person relaxes then the peeing mechanism switches on and the fluid is passed out of the system, whereas taking in even more water just means the mechanism stays switched off and that urine cannot be passed, whilst in the state of over-hydration.
A simple test of adequate hydration is to pinch the skin on the back of the wrist, where the arm meets the hand, if it springs back immediately then there is adequate hydration, if it takes time to return to its normal positioning without a ridge etc, then more fluid is required...that's just another test that can be used in addition to the colour of the urine checking.

3. One of the factors contributing to this has been the belief that we need to take action before thirst strikes. This is a message heavily promoted by sports drinks manufacturers, but again there's no evidence that this is the case.

And these days, people are being led to believe that they require isotonic style drinks for rehydration as well instead of basic water which always worked for each of us in the past...obviously a commercial angle which will become factual, eventually.



Most interestingly, they showed the South African army, who are carrying 60kg (132lb) packs in searing heat for hours at a time. The army carried out its own research into hydration...as a result of this, now the soldiers are not told they have to drink x amount. Their instruction is just 'drink when you feel thirsty'.

The sports shoe stuff was fascinating too.

Nice info! Really didn't know about the 2% and dehydration not having a basis that can be traced to any specific point in time or study.

[Goat]

Originally Posted by Tannhauser

Just an update on this thread. There was a program on a few days in the UK called 'Panorama: The truth about sports supplements'. Unfortunately, I don't think you can view this outside the UK, or at least I can't find a link for it. Anyway, a generally interesting program looking at evidence for sports shoes, BCAAs, rehydration drinks etc.

One of the things they looked at was the obsession with hydration. These were the conclusions from the top-echelon researchers:

1. No one knows where this 2% dehydration results in x% performance loss idea comes from.
2. Over years of monitoring marathon events, there have been zero deaths that could reasonably be attributed to dehydration. There have, however, been 16 (from memory) attributed to over-hydration caused by drinking too much water. There have been 1600 incidents of severe illness (again, from memory) caused by over-hydration.
3. One of the factors contributing to this has been the belief that we need to take action before thirst strikes. This is a message heavily promoted by sports drinks manufacturers, but again there's no evidence that this is the case.

Most interestingly, they showed the South African army, who are carrying 60kg (132lb) packs in searing heat for hours at a time. The army carried out its own research into hydration...as a result of this, now the soldiers are not told they have to drink x amount. Their instruction is just 'drink when you feel thirsty'.

The sports shoe stuff was fascinating too.

Is this it,

Panorama The Truth About Sports Products. - YouTube

Panorama The Truth About Sports Products. - YouTube

[elijah]

Yeah that's it. I just watched this. Wow, what an eye opener. Definitely makes a lot of sense to me.