Water Intake: Why Staying Hydrated Boosts Brain Power

Did you know that hydration plays a huge role in mental health and one’s capacity for rational thought? Our brain and body do not function as well as possible even if we are only 2% dehydrated!


The National Library of Medicine conducted a study on how hydration impacts one’s capabilities. Results show that the amount of water we drink impacts our neurological functioning, fatigue, stress levels, skin… The list goes on and on!


Overall, if you want to be your best self and function to your full potential, hydration is critical. Now we ask:

  • How do I know how much to drink?
  • Do I drink a different amount of water depending on the time of day?
  • What about working out? How does that impact the amount of water that I should drink?


I have the answers for you!


For a day that you are at rest and not in a dehydrating environment like a desert, there is a specific rule for water intake. Let’s get into this Golden Rule:

  • In the first 10 hours of your day, you should consume (on average) 8 ounces of fluid per hour
    • This translates to 80 ounces of fluid within the first 10 hours of being awake.


Now that we have our rule for drinking water when at rest, we can talk through how to assess hydration levels when working out! Here comes another rule!

  • To know how much water you should drink when working out, you can follow the Galpin Equation which goes as follows:
    • Take your body weight in pounds and divide by 30. This is the number of ounces of water you should ingest every 15-20 minutes of your workout.
  • Overall, if you’re exercising for around an hour, you can replace the 8 ounces of water (golden rule) with what you ingest according to the Galpin equation for exercise.


Say you’re working out outdoors in intense HEAT, or sweating TONS- should we still stick with the Galpin equation for water intake? YES, as long as you increase the values on the Galpin equation by 50-100%.

  • Sometimes when you sweat a lot during a workout, you cannot get enough electrolytes through water. In these instances, I suggest offsetting this dehydration through electrolyte drinks.
  • My favorite electrolyte drinks are BioSteel, Propel, and LMNT. Try them out!


Overall: STAY HYDRATED! You’ll be doing yourself a favor by positively increasing your energy, physical vigor, and clarity!

More than 50% of Americans struggle with mental health.

Headlight is now collaborating with health plans and companies to make therapy more accessible and affordable. Speak to a Care Coordinator today.