Hydration: A Quick Reference Guide
The impact on not only our physical performance (endurance, cardiovascular output, strength, flexibility/mobility, etc) but cognitive function (memory and creative, flexible, and critical thinking skills) when we are dehydrated is significant (just a 2% reduction in fluid intake can impair these functions).
It’s important that, especially as athletes, performers, and active people, we are adequately and optimally hydrating not just for performance but general health.
Here’s a quick guide on how to do just that:
Measuring your hydration level
Skin pinch or nail press tests
These are not extremely accurate as age, genetics, and medical conditions can impact the rate at which your skin bounces back or goes back to baseline color. However, if there is a significant change (decrease in rate by about 3 seconds) to how quickly your skin returns to baseline on a normal basis, that is a pretty good indicator of dehydration.
Examine urine color
The color of your urine is also not a fool proof method but, in general, if your urine is darker than an amber/honey color, you’ll need to increase your fluid intake. On the other hand, if your urine is clear/has very little color, you’ll want to dial back your fluid intake… immediately.
Subjective thirst
Thirst can be a reasonable guide though it does not keep up with what’s actually going on in the body. However, if feeling parched (dry mouth and throat), this is a great indication to consume more fluids (preferably not a diuretic like tea, coffee, or other caffeinated or alcoholic beverages).
How much fluid do we need each day?
We’re going to make this simple:
Every hour in the first 10 waking hours: Consume an average of 8 oz of fluid (80oz total), at a baseline (at rest, not including exercise).
If engaging in exercise: Body weight in lbs divided by 30 = amount needed to ingest per every 15-20 min of exercises (not necessarily on the dot, just sipping throughout and coming to this total by the end). Replaces the amount you would drink at a baseline for the time you’re working out, not in addition to.
If you’re working out or simply sweating in a hotter environment: Increase values by 50-100% depending on the temperature/amount of sweat.
Does caffeine count?
Short answer, no. Caffeine, whether it comes from tea, coffee, or an energy drink, should be supplemented at a 2 to 1 ratio with other fluids, ideally water and ideally with electrolytes (a pinch of salt will do).
Rate of consumption
The rate and times of fluid consumption can impact your hydration levels as well as waking in the night to use the restroom. It’s best to consume the majority of your fluid oz in the first 10 hours of waking, sipping throughout that period or, at the very least, trying not to consume the majority of it within a shorter period of time.
If you are not a night shift worker (or someone who’s sleep hours have them waking later in the day and sleeping later in the night/early morning) taper your fluid consumption after 5pm.
Electrolyte hype
Sodium, magnesium, potassium; these electrolytes can be found in the form of salt. In general, if you’re relatively sedentary and not in a hotter environment or sweating, you likely don’t need to add electrolytes to your water/beverage (unless, as stated before, you are consuming a beverage that acts as a diuretic like tea, coffee, or alcohol).
If you are exercising or physically exerting yourself, especially if you sweat during your session, you’ll also want to add electrolytes to your water.
Adding electrolytes can be as simple as adding a pinch of salt to every 8 or so oz of fluids. There are also plenty of electrolyte supplement packs/drinks to choose from, though I do recommend avoiding ones higher in sugar. Personally, I like LMNT (not sponsored).
What you should remember:
Measure hydration: You can get a good enough estimation of hydration levels via a skin pinch or nail press test, examining the color of your urine, or subjectively measuring thirst.
How much is enough: Drink approximately 8 oz for every hour in the first 10 hours of waking
If exercising (not in higher temperatures), divide your bodyweight in lbs by 30 to get the amount in oz you should be drinking for every 15-20 minutes of physical activity.
If sweating or in hotter temperatures, increase your fluid intake by 50-100%.
If consuming diuretics or drinks that contain caffeine (such as tea or coffee) use a 2 to 1 ratio of water to caffeine and consider adding electrolytes (just a pinch of salt will do) to your water.
Rate of consumption: Drink the majority of your fluids in the first 10 hours upon waking, sipping throughout that time period, then tapering your consumption after 5pm.
Electrolytes: Are not necessary unless exercising or sweating in a hotter environment or consuming diuretic liquids (as mentioned above).
Sources
Information for this post has been derived from Andrew Huberman’s podcast episode “How to Optimize Your Water Quality & Intake for Health.” I highly recommend listening to the sections on baseline hydration through to cognitive & physical performance (01:02:38-01:23:53) in full to establish a deeper understanding of the role hydration plays in both physical and cognitive performance as well as how to measure it and replenish it:
https://www.youtube.com/watch?v=at37Y8rKDlA&t=3758s
The Huberman Lab podcast is also a wealth of information for athletes and anyone looking to increase their health and fitness in any capacity and I cannot recommend it enough.
Other sources:
