How Much Water Should You Drink A Day?
How much water do you have to drink per day? Hint: it’s not simply eight glasses of water per day.
Drink! Drink! Drink More!
You often get to hear that you need to gulp down tons and tons of water, even if you aren’t thirsty. Thirst, you hear, comes too late and, besides, all that water also flushes “toxins” out of your body.
In reality, drinking this much is stress for your kidneys and the recommendation may simply be due to a misinterpretation of a 1974 book on nutrition. There also is no scientific research showing that thirst comes too late to prevent dehydration.
And if you regularly drink coffee or colas, you can count this toward the total liquids you drink per day, because the caffeine in them won’t dehydrate you.
The Science Behind The Video
If you would like to read the scientific review that went into this video, you can read it in full for free.
16 Comments
Actually I never heard of this 8×8 rule, but I read a lot of non medical articles (so it might be b-sh*t) which advise to drink 2-3 liters of water (depending on your mass, age, and whether condition), and if you drink more let’s say 5 liters it gives you even more benefits to your heart (lessens risk of heart attack)…
Isn’t there any scientific research covering that?
Good question! I failed to put a link to the single best source on the subject I could find and which answers your questions. Here it is and you can read it in full for free:
http://ajpregu.physiology.org/content/283/5/R993.full.pdf+htm
to maintain fluid balance in the body at a resting state to cover heat regulation, muscle usage, respiration the figure is about 2.5 litres of fluid per day – gained from fruit, veg, water, beer, coffee what have you. If you then exercise you need to add at least 1 litre per hour. If you live in a hot climate then again the FLUID BALANCE (body fluid homeostasis) required is different.
Quite why the ajpregu article should witter on about the 8*8 is concerning. The data for correct FLUID BALANCE is well established. Perhaps yet again it is the notion of how to promote a healthier lifestyle to the general public in a simple way (8*8) as opposed to having to give over scientific data which is of little interest to Joe Public.
BTW – places a strain on the kidneys? More of a strain than inadequate hydration? Are you really suggesting that you can place so much strain on the kidneys from fluid consumption that it is bad for the kidneys? I am pretty sure that water toxicity or indeed hydroencephalitis will get you before the kidneys were damaged, don’t forget the bladder has some say in the matter.
Just worked out that 8 * 8usfloz is less than 2 litres. I really do not know why you have made this video based on one article, which is not even empirical. To read the comments on youtube in regard to this issue just shows demonstrates to me that you have done more harm than good. PLease reaccess the message you are trying to put forward.
Oliver, the article contains numerous references on how dehydration is measured and what tests have been conducted in that field.
And yes, drinking more liquid than necessary is a strain on the kidneys, given that dehydration is unlikely to happen in a healthy individual.
Oliver, The message is simple. Its not needed to drink too much of water continuously forcing yourself.. Just drink how much ever you need whenever you want. It doesnt even say you should not drink too much water so dont misinterpret. If your body needs more water just drink it :D. The thing is some people don’t drink enough water absorbed in work.
Here is what i do. I never ever calculated how much i drink. I drink a lot of water until my thirst is quenched and I drink a lot water before my breakfast, lunch and dinner.. In that case I would be happy for my kidney to do more work than my digestive system doing more work and getting less calories 😀 ;D
You should at least have ahd a starting point of FLUID BALANCE. The American Journal has many EMPIRIC articles on hydration and performance. After re-reading your vaunted article I have decided that the article is sort of a scientific community joke which picks up on the 8*8. Your interpretation of the article is skewed and misrepresentative because you do not consider adequate hydration and the importance of FLUID BALANCE.
As for your opinion on the kidney, when you are a renal specialist I may consider what you have to say. Until that time I will view you as a dangerous quack spreading yet more quackery across the internet.
Good luck on your ADWORDS.
Unfortunately I can’t compress the entire theory of liquid household in the human body into a YouTube video. The main point is that a healthy individual can rely on his thirst to know when and how much to drink.
It is of course up to you to choose who you want to listen to.
Well, your “humble” clueless opinion is just that; your “humble” clueless opinion. AJP-Regulatory, Integrative, and Comparative Physiology is a pretty respectable SCIENTIFIC journal with a pretty respectable IF (= impact factor). And the article in question is an INVITED REVIEW. Writing a review basically means going through apalling amounts of research papers on a choosen subject and sum the things up. IMHO, the author sucessfully acomplished the goal. So, the the only community joke is your stupid comment. Produce some relevant scientific (not bro-scientific) paper that the author forgot to include or STFU.
Sorry, I was replying to Oliver.
peace guys, thanks.
Great video, Evil – shows that drinking to thirst works as well for humans as it does for all the other animals.
Forcing oneself to drink much beyond thirst risks low blood sodium, which can be very serious. For example, it is rare for marathon runners to collapse from dehydration, but much more common to collapse from low blood sodium caused by drinking too much fluid after sweating out salt.
A human needs to lose at least 2% water by body mass for it to begin to affect athletic performance, which for a 70 Kg person is 1.5 litres. Someone would have to be very hot to sweat 1.5 litres in an hour, so basically, most people are not losing enough fluid in a training session to affect their performance. This means you can replenish fluid after training rather than before or during if you don’t like running around with a stomach full of water.
With a decrease of only 2 percent total water weight, nerves that direct the function of the muscle tissue will be compromised, with noticeable decreases in muscle control and strength.Your strength training will decrease by about 21 percent and your aerobic capacity will drop by 48 percent with a water weight loss of about 2 percent. Protein synthesis and anticatabolism are in effect when muscle cells are properly hydrated. So, water is absolutely necessary for your
performance in the gym and your growth outside the gym.
I’m sure Mr. Yates would have preferred if you stated him as source:
http://www.dorianyates.net/dorian/site/showthread.php?t=903
Beyond that, he may be right about decreased performance when the point of dehydration has been reached, but, as stated in the video, it is very unlikely that this will happen if you simply follow your thirst.
I am sure that Russh meant to source his views also.
regarding the dehydration – hyponatremia paradox. ie. A person suffering from hyponatremia in an endurance event is also dehydrated.
http://www.rice.edu/~jenky/biopage.html
http://www.rice.edu/~jenky/sports/hyponatremia.html
http://www.rice.edu/~jenky/sports/salt.html