Do you really need to drink 8 glasses of water a day? An exercise scientist explains why your kidneys say ‘no’

The hotter climate and longer days have stimulated reminders to “stay hydrated” and drink 8 glasses of water or approximately 2 liters a day. 

Not to burst anyone’s water bottle, however wholesome humans can actually die from consuming an excessive amount of water. I am an exercise physiologist, and my studies make a speciality of overhydration and the way consuming an excessive amount of water impacts the body. Since water and sodium stability is vital to life, it is extraordinarily uncommon for humans to die from consuming an excessive amount of or too little fluid.

With the advent of spring, hydration problems are rooted in schools, sports and workplaces. These highly marketed hydration issues encourage comradeship and friendly competition to ensure that we drink the required amount of water throughout the day. 

Hydration and “Gallon Challenges” help the extensively held notion that water intake beyond physiological need or thirst is healthy

But that is not the case. The human body’s water demand and consumption mainly depend on how much water a person loses. The amount of water each person needs to drink depends mainly on three factors: 

  • Body weight. Bigger people need more water, 
  • Environmental temperature. When the weather gets hot, people sweat and lose water.  
  • Physical activities. The increase in training intensity will increase the loss of water due to sweat.

Therefore, a “one size fits all” fluid replacement strategy, such as drinking eight glasses of eight ounces of water per day, is inappropriate for everyone.

It is unclear where the recommendation for water intake “8 x 8” comes from. Perhaps, this two-liter intake threshold is derived from a misinterpretation of the original recommendations of the Food and Nutrition Board from 1945 and the European Food Safety Authority from 2017, according to which the recommended daily amount of water includes all drinks plus moisture contained in food.

This means that the moisture contained in foods, mainly fresh fruits, sodas, juices, soups, milk, espresso and, yes, even beer, contributes to this every day recommended water requirement. These guidelines cross on to signify that most of the recommended water content material may be performed without consuming extra cups of plain water. 

And, it’s far critical to be aware that at the same time as alcohol has diuretic properties — ethanol acts directly on the kidneys to make us pee extra — caffeinated drinks, like tea and coffee, do not increase urinary water losses above the quantity of water contained in those drinks.  

After all, you have heard from a whole lot of people that you need to drink more, more, more. Because overall body water stability, or what we workout scientists call homeostasis, is complicated, mammals survive by making real-time changes on the kidney. That’s why on the subject of hydration, our kidneys are king.

Within each kidney —we need only one (i.e., we’re born with a spare, simply in case) is an undercover network of aquaporin-2 (AQP-2) water channels that respond to a hormone known as arginine vasopressin. It is secreted by the posterior pituitary gland in reaction to nerve signals sent from specialised brain sensors which detect subtle changes in water stability. 

The kidneys will make molecular changes to each underhydration and overhydration within forty seconds in reaction to any upset in the water balance. These changes result from the mobilization armies of AQP-2 water channels, numbering approximately 12 million per collecting duct cell. 

This is why when we drink extra water than our body needs above thirst we immediately ought to pee out any extra water. Or when we forget our water bottle throughout practice, we stop peeing to preserve body water.

This quick coordinated action between the brain, cranial nerves and kidneys is far more efficient and precise than any phone app, gadget or personalized recommendation available.

Data shows that consuming approximately 2 liters of water per day reduces kidney stone formation in people with a record of kidney stones and reduces the number of bladder infections in people with a history of bladder infections. Improvement in skin complexion, kidney feature and constipation, with accelerated water intake, are not clearly supported by science. Drinking extra water alone does not help kids lose weight unless water consumption replaces the ingestion of higher-caloric drinks, consisting of soda, or makes people feel “full” earlier than meals.

Drinking water can have an effect on a few peoples intellectual state. Some research reports higher cognitive performance after increasing water consumption; while females with anxiety report compulsive water consumption makes them feel better, possibly from activation of reward circuits that increase dopamine. Many schizophrenic sufferers are compulsive water drinkers, pointing out that “voices” inform them to drink and that ingesting water suppresses these voices.

Of note, brain imaging research verify that superfluous consuming is unpleasant and calls for more muscular effort than drinking when thirsty.Our brain tries to discourage chronic overdrinking, or polydipsia, because “social polydipsia” causes chronic peeing (polyuria), which can lead to internal plumbing modifications such as bladder distention, ureter dilation, hydronephrosis and renal failure. 

So, do you want to drink 8 glasses of water per day? Unless you’re thirsty, consuming greater water will possibly now no longer provide advanced fitness blessings however possibly isn’t dangerous either.