TN50#108, Your Kidneys Clock Out, 20 March 2023

Hi Team,

Happy Monday and welcome to The Next 50 #108.  Let’s start with some questions!

  1. What percentage of dehydration will cause reduced physical and cognitive performance?
  2. How much water should you drink during a normal day, average temps and office work?
  3. How much water should you drink during a workout or periods of high heat and high exertion?
  4. When do your kidneys clock out for the day?
  5. What 3 things can you do to reduce the need to get up and take a leak during the night?

All these questions and a whole lot more were covered in The Huberman Lab Podcast, How to Optimize Your Water Quality and Intake for Health, from 6 March.

I’ve heard a lot of different opinions on how to maintain hydration over the year, I think the advice given on this podcast is solid based on the simplicity of the start points and the science behind those start points.

And how much you should drink is just part of the podcast, the other main topic is water quality, definitely worth a listen.

So let’s get back to those questions with some answers and links:

  1. 2%, if your just 2% dehydrated you are not performing as well as you could be, period.
  2. 8 ounces of fluid, on average, every hour for the first 10 hours of your waking day.
  3. During exercise ignore the 8 ounces thing and use the Galpin Equation, which is:

Body weight in pounds/30 = ounces you drink every 15 to 20 minutes

165/30 = 5.5 ounces every 15 – 20 minutes or 22 ounces or so every hour.

  1. Your kidneys work very efficiently for the first 10 hours you are awake, after this they work much less efficiently so you can greatly reduce your fluid intake; especially if you hydrated well during the first 10 hours of your day.
  2. Your going to have click on the link for this one, listen to Dr. H for 27 minutes and you will hear all the science behind these 5 questions and answers.

I have read a lot of books and listened to a lot of scientists talk about the circadian systems in our body, this is the first time I’ve heard about this specific system in the kidneys, how about you?

Here’s the really cool part, I’ve generally followed the recommendations from the pod and I’ve gone from getting up once a night to pee every other night or so to not getting up at all.  Thank you Dr. Huberman!

As always share the post with your team or anyone who might find it useful and let me know what you think!

Have a good one, Alex