Do You Know How to Properly Hydrate? It's Not as Straightforward as You Might Think
Hydration seems like it should be so easy: drink some water, go about your day, the end. Back in this blog’s early days, and when I first published The Primal Blueprint, my hydration advice was simple: drink when you’re thirsty. Over the years, however, my thinking on the hydration issue has become more nuanced. When I updated and expanded the most recent edition of The Primal Blueprint in 2016, I expanded on that basic advice to include more details about what we should be drinking and how much.
For the most part, I still think that “drink to thirst” is a sound strategy for the average person. Your body has a built-in, well-regulated thirst mechanism that will keep you from becoming dehydrated in normal circumstances. However, some folks, like the endurance athletes in the crowd, would be wise to take a more intentional approach.
Benefits of Proper Hydration and How It’s Regulated
Hydration is a critical component of optimal health. Digestion, muscle contraction, circulation, thermoregulation, and neurologic functioning all rely on having appropriate fluid balance in the body.
Your brain and kidneys are constantly working to maintain optimal hydration status. When you become even slightly dehydrated, several things happen. First and foremost, your blood osmolality (concentration) increases. Dehydration can also cause a decrease in blood volume and, often, blood pressure. The brain and kidneys sense these changes and release hormones and hormone precursors designed to restore homeostasis.1 For example, the pituitary gland releases an anti-diuretic hormone called vasopressin, or AVP, which tells the kidneys to hold on to water. Blood vessels constrict. Most importantly, a brain region known as the lamina terminalis initiates the powerful sensation we know as thirst.
Pay Attention to Your Thirst!
For most people, proper hydration is as simple as 1, 2, 3.
Tune in to your body’s thirst sensations and respond accordingly.
Tailor your fluid intake to your individual needs. Rules like “drink at least eight eight-ounce glasses of water” or “drink half your body weight in ounces” are all well and good, but they might not be right for you. There’s not a lot of scientific support for those nuggets of conventional wisdom. Some days you might need less or considerably more.
Make appropriate adjustments for exogenous factors like climate and exercise.
When it’s very hot, or you’re sweating buckets during some long endurance event, it’s best to stay on top of hydration rather than waiting for thirst to kick in.
Don’t Become Waterlogged
You can have too much of a good thing. While I’m all about the trend of carrying stainless steel water bottles everywhere we go for environmental reasons, there’s never any call to drink literal gallons of water. In fact, drinking too much can bring about the dangerous condition of hyponatremia, where excess fluid compromises the all-important sodium balance in your blood.
Hyponatremia can quickly become debilitating and even fatal. You may have heard the news stories of novice marathon runners losing consciousness after over-hydrating or radio station contestants drinking themselves to death in water-chugging contests. By and large, your kidneys can deal with you drinking more water than you need within reasonable limits. You’ll just pee it out. Still, there’s no reason to force yourself to drink water beyond your natural thirst.
Salt: A Hydration Gamechanger
Maintaining proper fluid balance isn’t just about how much water you have in your body but also the concentration of key minerals, notably sodium. When you become dehydrated, you may experience not only thirst but also salt cravings.2 Salt continues to get a bad rap, though thankfully the tide of conventional wisdom seems to be turning as more people recognize that salt is not the enemy. Salt—or rather, sodium—is essential in the truest sense of the word. Without enough, and without the right balance between salt and other minerals, our bodies literally cannot function. Sodium helps transport water through the walls of your small intestines, where 95 percent of fluid absorption takes place.
We Primal folks naturally consume less sodium than the average person since a large proportion of most Americans’ dietary sodium comes from hyper-processed foods that we avoid.3 For optimal absorption, I recommend adding a pinch of salt to your water, especially if you’re craving the stuff. You can also make a jar of sole ("soh-lay") water and add up to a teaspoon to a glass of water.
Do You Need to Add Electrolytes to Your Water?
Sodium is one of the main electrolytes, along with magnesium and potassium. Most Primal folks will get electrolytes by salting their food and consuming a diet containing nose-to-tail animal products and a diverse array of vegetables. However, keto dieters and hard-charging athletes or other folks who sweat a lot, like those who work outside in hot climates, probably need to add electrolytes to their water to ensure proper fluid balance. Check out my guide to electrolytes on keto. I’ll talk more about considerations for athletes below.
How to Stay Hydrated Without Drinking Water
There’s no question that good ol’ fashioned water is the best, most Primal beverage. Some people tell me they don’t like the taste of water. I can’t relate, but if you’re one of those people, you can also meet your hydration needs with a combination of:
Mineral water or any of the sparkling waters on the market (yes, sparkling water, or carbonated mineral water, is just as hydrating as regular water4)
Coffee, regular or decaf (no, coffee and caffeine aren’t dehydrating even during exercise5,6)
Hot or iced tea
Kombucha
Bone broth
Vegetable or fruit juice, though I’d caution you to limit your consumption of the latter
Still, I’d encourage you to work on embracing water. Maybe you need a water filter to make your tap water taste better. Try adding sliced citrus fruits, berries, ginger, cucumber, and fresh herbs to a pitcher of water to infuse flavor without a ton of sugar.
Remember, too, that we get up to 20 percent of our hydration needs met through food, especially fruits and vegetables. At the top of the list are the ones you’d probably expect: watermelon, cantaloupe, and other melons; lettuce and spinach; berries; celery; and squash. Carniflex enthusiasts, you still get some water from meat and the limited vegetables you might enjoy, but less than an omnivorous diet provides.
Designing an Optimal Primal Hydration Strategy
Best practices:
For most people, drinking to thirst is still the best recommendation. Athletes probably need a more engineered hydration strategy
Drink throughout the day. Keep water handy so it is available if you want it, but don’t force yourself to drink beyond thirst. If you’re constantly drinking water and in the bathroom every 30 minutes, you’re probably just cycling water in and out with no physiological benefit.
It’s not enough to drink water; you also have to absorb it. This is where salt comes in. Salt your food to taste, and add a pinch of salt to your water.
Eat high-water-content vegetables, plus some fruit if you want.
Remember, hydration needs and optimal strategies are idiosyncratic. Just as I advise you to experiment with your diet to find what works best for you, do the same with hydration.
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5957508/ ↩
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5957508/ ↩
https://pubmed.ncbi.nlm.nih.gov/1910064/ ↩
https://pubmed.ncbi.nlm.nih.gov/26702122/ ↩
https://pubmed.ncbi.nlm.nih.gov/24416202/ ↩
https://pubmed.ncbi.nlm.nih.gov/25154702/ ↩
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* This blog reflects my personal views and opinions and isn’t intended as medical advice, but I hope it will be informative and inspiring as you pursue a healthy, fulfilling life.