Jan 162020

How Much Water Do I Need: Hydration Simplified

How Much Water Do I Need: Hydration Simplified

“How much water do I need?” This is one of the most common questions I am asked. Unfortunately, there is quite a bit of confusing information floating around. Hydration does not have to be difficult, though! Your body offers important clues to help you monitor your own hydration status.

Why It Matters

Our bodies need fluid for many reasons. Fluid maintains the volume of our blood. This allows for nutrients, oxygen, waste products, medications, etc, to move through the body to the appropriate destination. Fluids cushion our joints, and along with fat, cushion our organs. Fluids help us regulate our body temperature as well. The list of benefits seems endless and this why this topic is discussed of often.

Can a Person Drink Too Much Water?

ABSOLUTELY! It is known as water intoxication and it is FATAL.

The kidneys play a key role in helping the body keep electrolyte levels just right. When electrolyte levels rise in the blood stream (dehydration), the kidneys hold onto water so that the blood can be diluted. The opposite happens when electrolyte levels become too low, the kidneys remove extra water (which is diluting the blood) and eliminate it as urine. If excessive water is consumed faster than the kidneys can eliminate it, the electrolyte levels become too diluted and the body can experience a (potentially) fatal electrolyte imbalance. This is called water intoxication.

Can You Trust Your Thirst?

YES! For most people early thirst is a reliable signal that it is time to drink. However, the elderly, those who are ill, and heavily exercising athletes are groups of people in which thirst may not be as reliable.

The Elderly

As we age our ability to recognize early thirst diminishes. This places the elderly at a slightly higher risk of dehydration. However, it can easily be fixed. Once fluid requirements are determined, a system of monitoring can be arranged. This usually looks like filling a series of water bottles each morning and making sure each is empty by bedtime.

Intense Exercise

Intense physical activity can cause a person to lose water faster than thirst signals can keep up. That is why it is so important to keep plenty of water close by if you are doing a heavy workout.


Did you know that medical professionals recommend fluids during illness because thirst signals are decreased and fluid needs are often higher? It has nothing to do with “washing” the germs away. This is particularly true for illness that involves fever, vomiting, and/or diarrhea.

All the Rest of Us

The majority of us, and our children, do not fall into these categories on a daily basis. We can trust that when we feel those first signals of thirst, it is time to have some water. Thirst is something that is meant to help us not just survive, but to thrive. Heed it!

Quick and Dirty Calculations

Now, for the fun of it, let’s talk about how fluid needs are determined. There are two textbook methods.

The first is : Body Weight (in kg) x 30 = Total mL of fluid needed per day

The second is: Number of Calories consumed = Number of mL of fluid needed day

However, if you are in the USA, the metric system is a bit confusing.

Therefore, a quick a dirty calculation is: Half of your current body weight (in pounds) = Number of ounces of fluid needed per day

If you currently weigh 150#, you need 75oz of fluid per day. This translates roughly into 9 glasses of fluid. This is the root of the common recommendation of 8-10 glasses of water.

The Story Urine Tells

However, calculations like these are only estimates. The best method for determine how accurate fluid calculations are is by examining urine. Yep, I said it. The next time you use the restroom, take a moment to see what color your pee is.

Urine that is the color of lemonade means you are appropriately hydrated. This is not lemonade made from a powder mix that contains yellow dye, this is real lemonade, which is a pale yellow. Think about the lemonade at a popular fast food chain that promotes eating less beef and more chicken.

Dark yellow urines means you need more fluid.

If your pee is clear, you are drinking too much water. Drinking so much water that your urine turns clear does not give you any extra benefits. All it does is make your kidneys work harder than is necessary. Plus, you spend all your time running to the bathroom and nobody has time for that!


The association between caffeine and increased urination has led to a widely held myth that drinks with caffeine do not count as fluid intake. I have even heard suggestions that if a have a cup of coffee is consumed, and EXTRA glass water should also be consumed to combat the dehydrating effects of caffeine. I am here to tell you, that research does not support this claim. Therefore, it is true that caffeine promotes urination, but research has shown that the impact is not great enough to cause dehydration.

Now What?

So now what? How do you go about making daily hydration simple?

  1. Fill a glass or water bottle and keep it close to you at all times. Each time feel a slight twinge of thirst, take a sip. This will help you tune into your body cues. Also, it will help spread out water consumption. Small amounts throughout the day help to limit the number of bathroom trips.
  2. Next time you go to the restroom, take a look at your urine. What does it tell you? Learn from it and act accordingly.
  3. Do a quick calculation of fluid needs by dividing your body weight in half. This will tell you a rough estimate of how much fluid you will likely need. Now Рand this is important Рnutrition calculations are always ESTIMATED needs. There is SIGNIFICANT variation among people. This number is not the absolute rule for how much fluid you need in a day. Your body is the ultimate guide when it comes to fluid needs and you need to listen to it. If you complete a hard workout and are extra thirsty, your body is telling you something important. If you set a goal to drink a certain amount of water per day, and yet you find yourself running to the bathroom every few minutes, and your urine is clear, your body is telling you something important.

Good hydration is an important step in caring for health daily, but please understand that it each person’s needs are unique. Just because an influencer on the internet is promoting drinking large amounts of water each day, doesn’t mean you should listen. The human body makes its need clear. We must be willing to listen to it if we truly want to experience authentic health.