The great Hyrdation debate: Well here is the... - Couch to 5K

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The great Hyrdation debate

24 Replies

Well here is the answer, might also be useful for you Steve and Rig, I'm sure you will read with interest. If drinking 3 -4 litres does me more good than harm, then by the same argument, I'm going to buy an oxygen bottle.

Read with interest.

bbc.co.uk/news/magazine-244...

24 Replies
gary_bart profile image
gary_bart

South Africa's top sport scientist, Tim Noakes, goes so far as to say that the whole "science of hydration" is bogus, and has been driven by sports drinks makers with a vested interest in "proving" that you need lots of _________ to responsibly complete the Comrades Marathon.

I haven't gone into it in great depth, not being someone who's expecting to end up in a situation when hydration is critical, but he sounds like he knows what he's talking about. What happened was they started getting people with breathing problems on the Comrades (which, just in case you don't know, is the world's oldest ultramarathon, between Durban and Pietermaritzburg, SA). It think it was breathing problems, but whatever it was, they were buggered, and it was a mystery why. At which point someone realised that they all had fluid on the lungs. A bit of detective work revealed that the syndrome (whatever it was) was hitting the most diligent "hydraters", and they were cured by being kept off fluids for a while.

The short story is that the Tim Noakes group of scientists now say that yes, hydration is important, but that the way you know when to take fluids is when you're thirsty. (I think the doctors say something like "it should be regulated by thirst").

Of course it's up to each of us to find out as much as seems to be relevant to our own requirements, and to do what seems to make sense. The idea that you can have too much of a good thing seems to make sense to me at the moment. If I accidentally encounter something that makes better sense, I'll follow that.

I hope that wasn't too vague to be useful to you.

ViaM profile image
ViaMGraduate

The European Food Safety Authority (EFSA) recommends an intake of 2.5 litres of water for men and 2.0 litres of water for women per day, via food and drink consumption. Of this, they suggest that 70-80% of the daily water intake should come from drinks, and the remaining 20-30% should come from food. This is supported by the NHS who recommends that women should drink eight 200ml glasses and men should drink 10 200ml glasses of fluid per day.

This is the formal advice on adequate intake of water. There is no formal advice on adequate intake of oxygen - at least I haven't come across any.

in reply to ViaM

The oxygen bit was meant as a joke lol. But the article sums it all up.

ViaM profile image
ViaMGraduate in reply to

Yes, the bit about oxygen in my reply was a joke too.

Basing opinions in one and only article is a joke too, lol.

Its proper research, I assume you haven't read the entire article. Its not written by ad men, it gives all the full references to be cross checked.

ViaM profile image
ViaMGraduate in reply to

Wrong assumption and actually the EFSA's recommendation is pretty similar to what the article says.

in reply to ViaM

youtube.com/watch?v=8dFlV-R...

Rignold profile image
Rignold

Interestingly the same Googl search that brings up that article/piece also brings up two articles from the Daily Mail: one gleefully trumpeting this debunking of the 8 glasses a day theory (the popular media do love a good debunking), the next one detailing how drinking 3-4 litres of water a day is the secrte to flawless skin.

It always amazes me how resistant people are to the idea of drinking more water. Eat more vegetables, get more sleep and drink more water are the thre pieces of advice that would improve 98% or people's health and general lives, but drinking water is the one thing no one wants to do. We'll eat the latest superfood berry or seed imported from the other side of the world at enormous cost on the flimsiest of claims, we'll pay £3.69 for coconut water because Madonna drinks it, but regular water, which is free and available almost everywhere in the UK at least, we make excuses to avoid it.

simply cannot imagine how anyone could have a fluid intake as low as 1.2l/day and think that adequate. That's 2 pints! I've drunk that by 6.30AM. I'll drink that much in the course of a workout (and indeed the standard advice - albeit not from Prof Noakes, of whom more later - is to drink an extra litre of water for every hour of moderate exercise). Do people not drink anything with meals? Of course we are all different and our intakes will vary depending on size, metabolism etc and the general rule of thumb is to drink when you are thirsty, as your body knows how much you need. But really do people only feel thirsty only twice a day?

Having watched that interview with Prof Noakes, it is worth noting that what he is talking about is prehyadration: taking onboard far more water than you need immediately prior to a race. I have never heard of such a practice. You are certainly not going to suffer hyponatremia from averaging 3 litres of fluid intake daily. Prof Noakes is a fairly regular fixture on some of the 'Bad Science' groups, usually for his anti vaccine views. I was just ready about him the other day actually, after his court case for professional misconduct has been postponed to November for rather odd reasons.

I was going to mention the GOMAD principle (Gallon of Milk a Day), which is very popular among various sections of the bodybuilding/powerlifting communities, but I fear taht might induce meltdown.

ViaM profile image
ViaMGraduate in reply to Rignold

I never feel thirsty and a large number of people have a very weak sense of thirst. Additionally, thirst is the seventh symptom of the beginning of dehydration in a list of around 15. I suffer from chronic dehydration so I have been told off by doctors many times so far.

dottiemay profile image
dottiemayGraduate in reply to Rignold

Don't really want to get involved in the right/wrong debate but I rarely get thirsty. It's one of the problems I have in remembering to drink enough.

When I was working, I'd have a cuppa first thing in the morning plus a glass of orange juice, hopefully another drink during the morning, then nothing else til mid-afternoon and early evening. So, maybe five cups a day. I do now try to force myself myself to drink a couple of glasses of water during the day but it does have to be a conscious thought!

in reply to dottiemay

Well that's no problem re the debate. But why drink when you are not thirsty, your brain would tell you to drink if you was thirsty. You don't eat if you're not hungry.

dottiemay profile image
dottiemayGraduate in reply to

Because I have recently been told I have chronic kidney disease!! No symptoms, no treatment needed, just regular blood tests to monitor it.

Whether or not it is related to not drinking enough, no-one is prepared to commit to but I have been advised to up my fluid intake to keep the kidneys working efficiently. Which reminds me...time for a glass of water! ;-)

ViaM profile image
ViaMGraduate in reply to dottiemay

I am exactly the same, never thirsty!

ViaM profile image
ViaMGraduate in reply to

As I mentioned above, I NEVER EVER feel thirsty. I have to have a bottle of water next to me so that I can remember to drink, as instructed by doctors in an effort to deal with my chronic dehydration, caused, obviously, by my lack of thirst in the first place.

Pigivi profile image
Pigivi in reply to Rignold

1 gallon milk a day??? :o)

I probably would die ! (ok, Italian adults don't really drink milk, and only about 10% is NOT lactose intolerant, but we do love our cheese!)

Agree - people are hydrophobe!

Good point, but what of Dr Tullekan and the highly credible BBC report, we are surely not going to say the opinion of the research highlighted by the BBC are not credible. This after all is titled "debate" so its interesting to read all views. I am of the opinion, I only need to drink more if I am using more, otherwise tea & coffee beverages count towards my water intake amongst other liquid refreshments. I don't buy coconut drink or any other type of milk drink other than full fat milk, sadly Sterilized milk seems increasingly hard to come by. Call me mad, but I entirely trust the information provided by Dr Michael Mosley and his team. I tend to have a cup of coffee or tea with my meals and sometimes sparkling spring water. Its rare for me to buy any product endorsed by a so called celebrity.

PS: I don't for one minute also believe we have been anywhere near the moon, lol. Oh I am cynical.

gary_bart profile image
gary_bart

I forgot to mention it: Interesting article. If running marathons, it would be necessary to study this in some depth, and do some experiments on oneself/ make some decisions. For 5 km, at least we can just take our chances.

By the way Rig, I would just like to say, I hope you are feeling better and on the mend.

Anaverageman profile image
AnaveragemanGraduate

Hussain,

Firstly I have to declare an interest. My job is a scientist involved in hydration. So with that in mind, id say two points.

1. All scientists are not dispassionate ... Thus in the BBC article (as was said.. Their aim was to 'debunk' .. There is no 'story' in saying 'all we've said for years is right '.. With that in mind, the first paper they quoted is true ( and a clever experiment) BUT ... Was only done ( if memory serves correctly on about 12 -16 athletes, all young, only on cycling). To draw BROAD conclusions ( as some have tried to do) from such a small experiment is not good science. Against this i could quote a good 20 plus papers that show the reverse.. But that's,science.. No clear cut answers..

The rest of it VERY old news... Heinz Valtins paper very good (there is NO evidence that 8 @ 8oz glasses of water what is required) but noone ever really suggests that any more..

Yes coffee and tea count, also juice and even beers can hydrate ( you lose some water but take more in than you lose but beware the empty calories!!)

Thirst is a good first approximation.. If your thirsty drink if you're not , don't worry about it!!! ( although thirst perception declines with age)

BEST way by far, check your urine colour ( its a real physical measure of your hydration) look up Lawrence Armstrong pee charts.....

Pale straw colour your fine , darker than yellow ,you can drink more...

Everyone is different.. What you need to drink dictated by lots of factors.. Temp. Exercise, age, sex ,weight, .. No hard rules..we are all different.. So check you pee colour... Plenty pee charts online but look for correct colour one from Armstrong.

in reply to Anaverageman

lol like it, interesting, good contribution.

Pigivi profile image
Pigivi in reply to Anaverageman

Good to know, without a particularly scientific background I have always gone by urine colour. - and thirst.

Anaverageman profile image
AnaveragemanGraduate

Link to Armstrong , scientist involved in hydration with us army for about 30 years....

hydrationcheck.com/about.php

Give you an idea...

Anaverageman profile image
AnaveragemanGraduate

something should perhaps be said with regard to the Noakes work.. his greatest contribution is to highlight ' hyponatremia' which can happen to endurance athletes. ( important for long distance runners). In a study a few years back post Boston marathon... they found at least one third of athletes post run should signs of mild hyponatremia ( low blood SALT levels).. the trouble is the symptoms of mild hyponatremia are very similar to those of dehydration ... so often people given more water to drink.. and that only makes people worse..if things dont get any better then think about replacing salt not the water post run....

when we run we lose BOTH water and also salt...

Current recommendations from the American College of Sports Medicine as follows:

if you exercise for less than 1 hour... drink fluid to replace the lost water... ( actually post exercise some evidence suggests milk is the best!!)

If you exercise for MORE than one hour ( aerobically so you are sweating a lot).. you need to replace both the water AND salt you have lost.. i always say to people you can always eat a salty snack..as well as drink.. although you CAN use sports drinks too but dont have to buy them... you can make them up yourself, with water , squash and a little bit of salt ( find recipes easily online)

hope this helps too..?

Pigivi profile image
Pigivi

I have just come back from an 8k run, easy, lovely, but... I forgot to bring my water - and I WAS thirsty - drank about a pint on one go as soon as I was home!

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