How Much Water Should You Drink?

Introduction by Pure Water Gazette Editor Hardly Waite.

The article below, from an extensive bodybuilding website, says several things that need to be said and repeated, since much of what is usually said and repeated about human water consumption requirements is pure nonsense.

The 8-glasses-per-day slogan has been mindlessly repeated for decades by physicians, nutritionists, diet gurus,  mothers, grannies, teachers,  and others who should know better.  Who knows where it originated.  You would think there was an Eleventh Commandment that says, “Thou shalt drink eight eight-ounce glasses of water per day.”

Does a slender woman who works in an air conditioned office and eats salads and fruits need the same 8-glass water ration as the beefy construction worker who spends the day in the sun and wolfs down potato chips and salami sandwiches?

Do both the secretary and the construction worker need the same amount of water on Tuesday and Friday?

Since we sweat more some days than others, and we pee more some days than others, and we eat more some days than others, and we sleep more some days than others, and we work harder some days than others, it would seem obvious that we need more water some days than others.  And it should be equally obvious that that people in different geographical regions, under different socioeconomic circumstances, and in varying states of physical and mental health don’t all need exactly eight eight-ounce glasses of water per day.

So how do you decide how much water you should drink? The Pure Water Gazette endorses the radical view that plain water should be your drink of preference and that you should get a drink when you feel thirsty and drink no water if you aren’t thirsty.

How Much Water Do You Really Need?

by Dr. Mauro Di Pasquale

Almost everyone agrees that water is good for you and that the biggest problem with water intake is that you don’t drink enough. We have all had it drummed into us that we need to drink at least eight glasses of water a day. That it’s important to drink water before and during exercise.

That coffee and tea don’t count because caffeine can dehydrate our bodies. And that you can’t trust your thirst as an accurate measure of when you need water since if you’re thirsty you’re already dehydrated. Well think again. According to a recent review in the Journal of Physiology, most of these accepted truths seem to be myths.

This review looked at the scientific evidence of the 8*8 mantra about drinking at least eight 8-ounce glasses of water a day, and found that there really was none.

The claimed benefits of taking in that much water each day, including benefits for weight loss, bowels, fatigue, arthritis, mental alertness and headaches, losing weight, preventing constipation, are also mostly unsubstantiated.

Other Water Myths That Are Debunked In This Article Include:

  • By the time a person is thirsty that person is already dehydrated. This in fact isn’t true and the best measure of how much water to drink is your thirst.
  • Dark urine means dehydration. Again that’s not strictly true either as there are many other factors that can contribute to dark urine.
  • Caffeinated beverages dehydrate us. As you’d expect much of this is also unsubstantiated. In fact, contrary to popular opinion, a recent study has found that coffee, tea and sodas are hydrating for people used to caffeine and thus should count toward their daily fluid total.

While this review focuses on the validity of the various water myths, no one seriously disputes that getting enough water is crucial. However, fears of dehydration and the constant barrage telling us we don’t drink enough water, has led to a mistaken belief that the safe thing to do is to drink as much and as often as possible. But drinking too much water can be hazardous to your health.

Too Much Water?

The reason why over hydrating can be dangerous is that when we consume large amounts of water when exercising, blood plasma (the liquid part of blood) increases, while the sodium concentration in the body fluids decreases, both as a result of the dilution by the water but also because sodium is lost by sweating.

Hyponatremia, or low blood sodium, generally happens after drinking too much plain water and can lead to adverse effects and tissue damage, and interfere with brain, heart, and muscle function.

Early symptoms can be difficult to spot and include:

  • Confusion
  • Nausea
  • Fatigue
  • Muscle cramps
  • Weakness

More severe symptoms can include vomiting, muscle twitching, delirium, seizures, coma and death.

A new review of three deaths of US military recruits highlights the dangers of drinking too much water. Like in sports, the military has traditionally focused on dangers of not drinking enough, especially under conditions often associated with exercise and hot conditions. However, getting overzealous over the need to drink large amounts of water and over-hydrating can have deadly consequences.

So How Much Water Should You Drink?

My recommendation is to drink when you’re thirsty, and if you think you should be drinking more, don’t overdo it. As far as drinking water in and around exercise, I’ve outlined a few simple guidelines that will make sure you’re well hydrated without hitting any extremes.

Within an hour or so of training, drink a few glasses of water so you start well hydrated. While training you can drink a glass or so of water for every 15 minutes you train, especially if you’re sweating it out.

However, even during times of heavy sweating don’t take in more than a quart and half of water per hour. As far as how much your daily intake of water should be, The American College of Sports Medicine says that 12 quarts is the maximum amount to drink in a 24-hour period.


Dr. Mauro Di Pasquale’s Website

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