We all know that water is important for our health. But is drinking a gallon of water a day something to consider?

In this article, we’ll talk about the science of hydration, discuss why (an how) you should drink a gallon of water a day, and share our water experiment results.

So, grab a glass of agua and let’s get started. 

Drinking a Gallon of Water a Day Ryan and Alex Duo Life

drinking a gallon of water a day

What happens when you drink a gallon of water a day? We wanted to find out.

Alex and I are hydration freaks. Let’s just get that out there. It took a few years, but after researching and noting how we felt when we did (and didn’t) drink water, it became a no brainer.

The importance of drinking water was a concept first introduced to us through Alex’s bridal magazines. Every magazine proclaimed that drinking water would make for a fresher bride, with glossier hair and brighter skin.

Of course, we knew that drinking water was vaguely important. We had heard of the 8×8 rule (drink eight 8-oz. glasses of water daily), but couldn’t remember why or from whom.

Mostly, I would remember hearing my mother’s voice in the back of my head always telling me to drink water.

So, my question now was, how different would I feel if I drank, say, a gallon of water (aka 3.9 liters or 128 fluid ounces) a day?

I was also curious if I could balance a gallon of water on my head longer than Alex. It was a close one, but I think the answer is yes.


why should anyone drink a gallon of water a day?

It turns out, nothing can happen in our bodies without water. Water is the vehicle that carries every nutrient, hormone, chemical messenger, enzyme, and electrolyte.

The following are a few key examples of critical functions inside the body (such as breaking the chemical bonds of nutrients in food to make them bioavailable) that cannot take place without adequate hydration.

1. Blood delivers nutrients

Our blood is 92% water, keeping the plasma afloat so they can deliver nutrients, hormones, and proteins to the cells. Yes, our blood can get “dehydrated” too.

2. Cells absorb nutrients

When all of these compounds arrive at the cells, they can only enter through osmosis, which is a process that requires adequate water and cell hydration.

3. Cellular hydration creates energy

Inside the cells, water is required to fuel up the mitochondria (aka the power plant of the cell). This process is like the spark in a combustion engine. Without it, the car (or your body) does nothing.

4. Waste removal

The energy creation and metabolism processes that occur in the cells leave behind debris. Water washes away this debris and toxins out of your cells and body.

Proper hydration also helps keep you regular and less constipated when you drink water.

5. Whole Body lubrication

Water is a component of every tissue, organ, blood, and bone. When they are deprived of water…

  • Our spinal discs take a beating
  • The cells that make up our organs stop receiving chemical messages and are more at risk of disease
  • Blood thickens and body responses slow down
  • Joints ache, and the risk of arthritis increases

… just to name a few. 

In short, you should drink adequate water so that your body functions well. But, in addition to supporting all body processes, there are more tangible reasons to drink a gallon of water a day.

what are the benefits of a gallon of water a day?

But who cares about what water does for my body after hydrating. What about the benefits? The following are a few key benefits of proper hydration that are proven by science. 

1. Better skin

Dry skin from dehydration promotes aging and wrinkles. What’s more, is the older we get the more water we need to drink. As a fetus, we are about 75% water and as an elderly person, we are about 60% water.

Why do you think hyaluronic acid is so popular in anti-wrinkle skincare products? It holds 1000 times its weight in water.

2. Increased happiness and productivity

The University of Connecticut Human Performance Laboratory found that mild dehydration caused a worsened mood and made easy tasks feel difficult.

When dehydrated, your body responds by slowing down. Therefore, when you’re tired mid-morning, and you want to reach for caffeine, reach for water instead.

3. No brain fog

Our mental and emotional health depends on proper hydration. Research at Tufts University found that student-athletes who failed to drink enough water were more likely to report fatigue, depression, confusion, anger, and problems concentrating.

4. Weight loss

To top it off, drinking more water has been linked to weight loss. A Humboldt University study found that drinking just 0.5 liters (about 2 cups) of water could increase metabolism by up to 30%.

On top of that, drinking water helps satiate your appetite, preventing you from overeating. That’s why one of our mottos is ‘water first’ before going back for second helpings.

why is a gallon a day a "Challenge"?

We had the same question. If water is so critical to our health and bodily functions, shouldn’t proper hydration be easy?

In a perfect world, yes. But, here is why we all struggle to stay properly hydrated. 

1. We’re too smart

The brain (which is 85% water) is responsible for monitoring hydration, and it’s kind of a selfish worrywart.

Therefore, when water levels get low, the brain hogs water, taking it away from other areas of the body like the skin, muscles, and organs. 

Then, when the brain is running low on water, it finally sends out the thirsty signals. What this means is if your mouth is dry, you have probably been dehydrated for at least 24 hours already.

Unfortunately, we cannot rely on our bodies hydration signals. Instead, we need to create good habits around hydration. A gallon a day challenge does just that. 

2. We store fat but not water

Unlike camels, our body does nothing to store or replenish water. Hydration is 100% our responsibility. What’s more, is according to the Center for Disease Control, we are slacking.

In the United States, 7% drink 0 cups of water a day, 36% drink 1-3 cups, 35% drink 4-7 cups, and 22% drink 8 or more. That means 4 out of five people in the U.S. are not drinking enough water.

By the way, there are 16 cups in a gallon. So yes, drinking a gallon of water a day is going to be a challenge. Next, we’ll talk about a few key indicators for dehydration.

What are the Signs of Dehydration

A good way tell if you’re already drinking enough water is by looking at your urine. Your goal doesn’t have to be crystal clear. Instead, a pale yellow means you’re well hydrated.

If you’re dehydrated, here are the warning signs to look out for.

1. Headaches

Your brain is stabilized by a fluid-filled sac. When dehydrated, the sac provides less padding for your brain, resulting in headaches.

2. Dizziness

Dehydration lowers your blood pressure.

3. Dry skin and lips

We noticed this big time in our gallon of water a week results. Water is a significant component of all internal and external tissues.

4. Bad breathe

Saliva production slows down when you are becoming dehydrated.

5. Constipation or bloating

Your body is trying to ration what little water it has to work with. Digestion requires water to keep things moving. Staying hydrated improves your poop health.

6. Hunger

When dehydration kicks in, your brain can confuse hunger for thirst. If you’re hungry, but it’s not mealtime, reach for a big glass of water instead.

Compelling, right? But what about the concerns of drinking too much water?

How much water = proper hydration

Is a Gallon of Water a Day Too Much?

Over-hydration only becomes toxic in adults when you drink 6.5-9 liters (1.7-2.4 gallons) of water in the span of a few hours, according to studies.

Believe me, you have to really, really try to do that, and we wouldn’t worry about it. Drinking a gallon of water a day is not bad. And according to the numbers, 4 out of 5 people are chronically dehydrated. Drinking more water cannot hurt. 

How Much Water to Drink in a Day?

A rule of thumb for how much water you should drink is taking half your body weight in pounds and drinking that many fluid ounces.

For example, a 200-pound person should drink 100 fl. oz. of water a day. Some people need more, while some need less, but it’s a good starting point.

For us, we were ready to go all-in, and aimed for the easy, visual cue that a gallon of water sitting on the countertop gives us. One gallon of water is 128 fl. oz., so it should more than fulfill both of our day’s water needs.

So, we bought two jugs, wrote our names on them, and placed them on the kitchen table. Our water experiment became a mini-competition!

Our gallon of water a day experiment

We did the math. Taking a sip of water (approximately 2 ounces) every 15 minutes should do the job from 7 AM to 11 PM. How hard could it be to drink a gallon of water a day? Harder than you think.

Knowing that we gulp down water when we wake up and work out, we thought this challenge would be a piece of cake. Not quite.

Once immersed in work or cooking, it’s easy to go for an hour or more without drinking water.

Plus, there was a debate on whether or not tea or coffee counts.

According to studies, 20% of the water we intake every day is from food (mainly fruits, vegetables, and drinks). Nutritionists agree that unsweetened tea and coffee should count towards our daily water goals.

For our experiment, we wanted to keep it pure and drink a full gallon of water. Any other drinks and foods we may consume throughout the day would be a bonus. As Alex’s Chinese mother always says, it doesn’t count if it’s not water.

Our Experience

The first day, we worked steadily to drink from our gallons. We weren’t just at home working, though, so we each filled up a 1 liter Nalgene to take with us to the mall.

Frankly, everything was just normal, and we didn’t feel bloated. We also didn’t have to run to the bathroom every 20 minutes. Things were, well, as usual.

At the end of the evening though, we both had to play catch-up. We tried to drink up most of the water around dinnertime and took big gulps.

I had about a liter to go. It felt like we were in the airport security line, gulping down water like a champ before it was confiscated.

The following days we planned better and made sure our gallon followed us from our desk to our gym to the kitchen.

Our Results

After a week, we started seeing and feeling the benefits of a gallon of water a day. What’s more, is it felt like our bodies craved water. Once we got used to a gallon a day, we couldn’t go back.

Our skin felt and looked plumper, our workouts were smoother, and we felt more alert. On top of that, we felt big improvements in our sleep.

If you’ve read some of my other articles, you know that sleeping well is massively important to me. Experiencing burnout and low testosterone at age 28 will do that to you.

I had a hunch that my worst nights of sleep occurred when I was most dehydrated. To me, a low quality sleep means a night full of vivid dreams and waking up tired in the morning.

So, I decided to test this theory with some sleep tracking tools during our gallon of water a day experiment.

Here’s how we felt after a week of drinking a gallon of water a day:

  • We slept better, and my increased water intake reduced my vivid dreams.
  • On average, better hydration yielded better sleep. I measured 10% more REM sleep, using the Pillow App paired with an Apple Watch. 
  • We woke up less tired in the morning without back and neck pain, and experienced reduced dry skin, better breath (only Alex reported this for me), and higher productivity.

Our Conclusions

  • Dehydration negatively affects sleep quality.
  • To stay adequately hydrated during the day, you should go to the bathroom every 2-4 hours.
  • A best practice is to drink water first thing every day. Keep a full water bottle on your nightstand and drink it before getting out of bed. It’s not possible to catch up on hydration when you fall behind during the day.

Convinced that you should try drinking a gallon of water a day? Here’s how to get started.

How to drink a gallon of water a day

First, let’s make one thing clear. Drink water only. No sports drinks, juice, or soda. Actually, if you are still drinking soda, you need to quit.

Most of the fancy marketing for sports drinks is just that: fancy marketing. Electrolytes in those drinks are processed and contain particle sizes far too large to enter our cells through osmosis. Therefore, they are useless.

As for coffee, the myth that its diuretic side effects make us dehydrated is not valid. However, it’s still a great idea to drink in moderation to avoid caffeine addiction. Most everything else has loads of sugar and empty calories.

To hydrate better, you need to start by keeping a gallon of water on your nightstand for the morning. Start your day with a lot of water, and find a system to make drinking water accessible.

Our recommendation is to create a schedule for drinking a gallon of water a day. Our goal was to drink half a gallon in the first third of the day (by about noon according to our schedule). 

On the days we left the house, we liked filling up our Nalgene bottles from our gallon jug to make it easier to measure our progress while keeping it convenient and accessible.

Don’t like drinking water? Learn to. You can use your words to empower yourself in your new habit.

So let’s drink to your health!

3-Day Fasting Guide Printable PDF Ryan and Alex Duo Life

3-Day Fasting Guide (Printable PDF)

Download and instantly access the 3-Day Fasting Guide including the following.

  • Step-by-step checklist for before, during, and after your successful 3-day water fast.
  • A journal to track your experience and hunger levels.
  • Critical reminders and a suggested hour-by-hour meal plan to break your fast.

Plus, we’re just an email away for support.

Or, download for free.
As Seen In Feature Bar Ryan and Alex Duo Life

Hey we're Ryan and Alex

A husband-wife duo, two engineers, and the creators of Ryan and Alex Duo Life. 

After eight years working in the corporate world as engineers, we left our to tackle our true passion:

Helping highly motivated couples optimize their relationship and health by cutting through the muck and sharing what the research says works.

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