How Much Water Should You Drink in a Day? Learn the Golden Rule
Water plays a crucial role in keeping our bodies functioning properly, from regulating body temperature to aiding in digestion to transporting nutrients.
But with so many conflicting opinions and recommendations out there, it can be challenging to know exactly how much water you should be drinking each day. Some say it’s eight glasses a day. Others insist it’s more like a gallon. And others suggest you should only drink to thirst. It’s enough to make your head spin faster than a hamster wheel!
But fear not—we’re here to cut through the confusion and get to the bottom of how much water you should really be downing. But first, let’s lay some groundwork.
What Is Hydration?
Hydration is the process of supplying enough liquid to our bodily tissues to maintain proper function. The keyword here is “enough”—not too much, not too little. We’ll dive deeper into this concept shortly.
The reason we need to hydrate is that water is essential for life. Our bodies are, after all, about 60% water. H20 supports everything from blood circulation to skin health to waste elimination.[*]
Maintaining proper hydration involves achieving fluid balance, which means keeping the right amount of water and electrolytes like sodium, chloride, and potassium inside and outside our cells.[*]
How the Body Maintains Proper Hydration
The body loses water throughout the day, primarily through urine and sweat but also from bowel movements and breathing. To prevent dehydration, you must replace the lost water by consuming water (or water-rich drinks) and food daily.
Fortunately, your body is an impressive fluid-balancing machine. A complex system of hormones and organs work together to regulate fluid levels in the body.
For example, imagine you’ve just finished a spin class and your body is low on fluids. Without conscious awareness, osmoreceptors in your brain detect a decrease in blood volume and signal the hypothalamus to secrete ADH. This hormone instructs the kidneys to reduce fluid loss via urine, conserving water for the body.[*]
Meanwhile, the hypothalamus activates the thirst mechanism, prompting you to reach for a cold glass of water to replenish the water you’ve lost. Through this intricate process, your body restores fluid balance and maintains optimal hydration levels.
How Much Water Do You Need?
You’ve probably heard of the “8x8” rule, which suggests drinking eight 8-ounce glasses of water daily. This advice originated from a recommendation made by the Food and Nutrition Board of the National Academy of Sciences in the 1940s, which stated that adults should drink 84 ounces of water daily.[*] This guideline eventually evolved into the 8x8 rule.
Despite its widespread acceptance, there is no scientific evidence to support the notion that the 8x8 rule promotes better health. In fact, a thorough review published in the American Journal of Physiology found no evidence to suggest that this guideline offers health benefits compared to drinking other amounts of water.[*]
Of course, this doesn’t mean that we should put the kibosh on drinking water. We need to consume enough water to function optimally. However, there can be unintended consequences if we drink more water than our bodies naturally crave.
In other words, the best advice is to listen to your body and drink water when you’re thirsty.
Factors Affecting Thirst
How thirsty you get will depend on a multitude of factors, including:
- Where you live: If you live in a hot, humid, or dry area, or at high altitude, you’ll need to drink more water to compensate for increased water loss.
- Your environment: Spending more time outdoors in hot temperatures or in a heated room can make you feel thirstier and require more water intake.
- How active you are: Being active during the day or engaging in intense physical activity requires you to drink more water to cover the fluid loss through sweating.
- The temperature or season: Warmer months may require you to drink more water due to increased perspiration.
- Your health: If you have an illness that is triggering vomiting or diarrhea, you’ll need to drink more water to replenish the lost fluids. Health conditions such as diabetes and medications like diuretics can also make you lose water and require more hydration.
- Your body weight: Just like bigger people need more food, those with a heavier body weight also need more water to support their bodies.
- Your age: Older adults are more vulnerable to dehydration and may need more water than younger people.[*]
- Pregnancy or breastfeeding: If you’re pregnant or nursing, you’ll need to drink extra water to support your body’s increased demands.
- Your diet: Consuming caffeinated beverages, salty or spicy foods, and a low-carb diet like keto can increase water loss and require more water intake. More water is also typically needed if you don’t eat many high-water foods like fresh or cooked fruits and vegetables.
The Dangers of Overhydration
Drinking too much water, especially plain water without added electrolytes, can dilute blood sodium levels, leading to a condition called hyponatremia.
This is particularly evident in endurance athletes, who commonly suffer hyponatremia due to overhydration during races.[*] This condition can lead to symptoms like confusion, lethargy, headaches, and cramps. In severe cases, hyponatremia can cause brain damage, seizures, and even death.
Why is being low in sodium and other electrolytes so dangerous? Electrolytes are minerals in our bodies that carry an electric charge. Like water, electrolytes are lost daily through urine, sweat, and other bodily functions and must be replaced through salt, food, and supplements. Electrolytes are vital for many bodily functions, such as regulating fluid balance, nerve and muscle function, and blood pressure.
So, when you drink too much water, you dilute the levels of electrolytes in your blood. This can cause things to go awry.
The Key to Proper Hydration
So, what is the answer to proper hydration? It comes down to two ingredients:
- Drinking water to thirst
- Consuming enough electrolytes through salt, food, and supplements.
The easiest solution? Drinking electrolyte water to thirst! By doing this, you prevent both dehydration and overhydration. You take in the perfect amount of water that your body needs while restoring your electrolyte levels.
The easiest way to make electrolyte water is to add a high-quality electrolyte mix, such as IQMIX, to a water bottle and drink from it throughout the day whenever you get thirsty.
Each packet of IQMIX contains the following:
- 500 mg sodium
- 380 mg potassium
- 750 mg Magtein®, a clinically studied form of magnesium (Mg L-Threonate) that crosses the blood-brain barrier[*]
- 250 mg of super-concentrated lion’s mane mushroom, which supports brain health and function[*]
IQMIX is safe for those on a low-carb diet or those with diabetes, as it contains zero sugar and only one gram of carbs per packet. A much better option than sugary sports drinks!
It’s available in delicious flavors, including Peach Mango, Lemon Lime, Blueberry Pomegranate, and Blood Orange. Try our 8-Stick Sampler to find your favorite flavors!
The Bottom Line
There is no magic number of glasses of water to drink each day. The amount will vary depending on a multitude of factors.
The best rule of thumb is to drink water to thirst. Even better? Add an electrolyte supplement like IQMIX to your water. This way, you’ll be replacing both the water and electrolytes you lose—and your taste buds will thank you for the extra pizzazz!