Which position is better to drink water

Drink right!

SEND DATE Sun., 09.08.09 | 5:03 pm | The first

Drinking keeps the brain fit - because the thinking organ needs a constant water content. But it's not just about a certain amount per day, but also about the right time. Those who drink too little and at the wrong time reduce their mental performance - we took the test and made volunteers sweat in the sauna. Before and after it was a thought test ...

If you drink properly, you think better!

Summer, sun, hot days: the higher temperatures demand a lot from the body. In order not to overheat, its cooling system runs at full speed. This works mainly through the skin: sweat evaporates and cools the body. Even without physical exertion, you lose half a liter of water every day through sweating. If it's hot or if you play sports, you sweat more. In addition, even more fluid is lost: water evaporates through the breath and of course it also leaves the body through the urine - together that makes a good two liters a day.

What does water do in the body?

The metabolism constantly needs water for many functions and organs, including during sleep. Water is not only a thermoregulator, but also a transport and solvent as well as a liquid component. Water is especially important for

  • the blood: 90 percent water
  • the brain: 70 percent water
  • the kidneys: they filter about 180 liters of blood daily
  • the muscles: water also serves as a building material
  • the liver: the detoxification center works with water
  • the skin: especially for the sweat glands
  • the intervertebral discs: water ensures their volume.


Hunger can be endured longer than thirst: You can go hungry for weeks or months. But after only about four to six days without hydration, a person dies of thirst. When the outside temperature is high, for example in the desert, things can go faster. Even a baby can die of thirst much faster - within 48 hours.

Many people drink wrongly

According to experts, a creeping fluid deficit is very common because many people drink too little: Even the majority of Germans, especially children, regularly drink around 20 percent below the optimal amount. But many people not only drink too little, but also not at the right time: only with meals, often only in the evening, or only when they are already feeling very thirsty. That is wrong, say experts like Günter Wagner, nutritionist at the Institute for Sports Nutrition eV in Bad Nauheim: "Many believe that they can get their water at any time, for example in the evening. But those who do not drink during the day, and regularly , and even when he has to exert himself physically or mentally, he weakens his mental performance. "

Process information quickly in everyday life

The nutrition researcher has specialized in the topic of drinking for years and advises athletes and other interested parties on how they can drink optimally. Together with Günter Wagner and the cognitive psychologist Dr. Siegfried Lehrl took the test of W for Knowledge: How does fluid deprivation affect mental performance? In half a day you lose about a liter of water through breath, sweat and urine, even if you only sit at your desk. We simulated this loss with three sauna sessions in which eight volunteers were supposed to sweat out about a liter of water. The young men and women completed a small thinking course. Memory span and information processing were tested - the test subjects had to memorize syllables and rows of numbers, quickly read and write down rows of letters. "These tasks represent what you have to do in everyday life - especially the memory span and the speed of information are important because they play a role in complex actions and decisions, for example in the office during meetings or in traffic," said the psychologist Siegfried Lehrl.

Sweating for science

After the first test, the test subjects formed two groups: four of them were supposed to drink in the sauna and during the breaks in between, the other four not. All had to do a total of three saunas, before they had to step on the scales. In the case of non-drinkers, a pound of weight loss should indicate that they have actually lost a liter of fluid - through sweat. In contrast, the body weight of the drinkers should remain constant, which shows that they were able to compensate for the loss of fluid through drinking. It worked - in fact, the non-drinkers lost over a kilo of weight within an hour and a half with three saunas during the test.

Thirst goes to the mind

After the sauna, the test was repeated with the same tasks but different content. And in fact, there was a clear difference: Those who were allowed to drink did 33 percent better after sweating together than those who were not allowed to drink. "That is a very clear difference, and this little experiment results in what we have already scientifically confirmed in large studies with many test subjects: dehydration reduces mental performance, especially memory span and information speed - what brain researchers call working memory", says Günter Wagner. "And that is very important in everyday life, by the way, especially for students and pupils who learn a lot and have to exert themselves mentally."

Refilling doesn't really help

But if you think you can quickly add the right amount of water, you are wrong: two hours after the sauna, the experts gave all participants their brain teasers again. During these two hours everyone was allowed to eat and drink what they wanted. The non-drinkers thus had the chance to regain the liter of fluid that they had previously lost in the sauna. The test, however, again showed a clear advantage for those who were able to absorb fluids constantly during the sauna: 19 percent better performance in thinking tasks, is the result. "This shows that the body cannot compensate for a deficit that has arisen so quickly. So if you think you only need to drink more and the balance is right again, you have to take into account that recovery after the deficit takes some time. This shows that you should drink before the exertion, i.e. before studying or before the work meeting in the office - and not afterwards, "says Günter Wagner.

This is how you drink properly

The drinking expert therefore advocates breakfast with drinks, especially for school children. Students should also drink before the lecture or during it, if at all possible: Another study carried out by Wagner at the University of Erlangen found that students who were allowed to drink during the lecture retained more and were more attentive and focused. Incidentally, only water was drunk during the experiments - power drinks are not necessary at all. But three rules of thumb should be observed:

  • Quantity: It should be around 1.5 to 2.5 liters a day, according to the official recommendation of the DGE (German Nutrition Society).
  • Time: Drink continuously, always in small amounts, not just early in the morning and then again in the evening. Therefore it is best to always have the water within reach. You should drink before mental exertion and, if possible, during it, so that the brain is always optimally supplied.
  • Water is enough: Nutrition researcher Günter Wagner recommends mineral water with potassium and sodium, which enables the body to bind the water. But plain tap water is also possible - after all, it is the best controlled food in Germany.

Addresses & links

The German Nutrition Society gives tips on how to drink properly:
www.dge.de

Author: Johanna Bayer (WDR)

Status: 06/13/2014 2:49 p.m.