Key Takeaways
I enjoyed drinking so much water—more than I thought I would.In practice, 13 cups wasn’t quite as daunting as it looks, and once I got into a bit of a habit of opting for water, I was in a good position.I feel better, both mentally and physically, for it too.

I’ll be honest. I don’t drink enough water. I drink water when I’m working out, and sometimes have a glass at home, but I really should be drinking more. According to the Academy of Nutrition and Dietetics, the average man should be drinking 13 cups of water a day, which is about a liter more water than you’d drink following the previous popular advice to drink eight 8-ounce glasses of water a day.

Why Do We Need So Much Water?

“Thirteen cups a day is a good target for getting the benefits of regular hydration,” says Christy Swaid, a wellness mentor, nutrition expert, and former athlete.

“But 13 cups may not be enough in the context of exercise, heat, sun exposure, sickness, fever, or air travel. Many people forget to drink enough water or choose not to with the intention to avoid going to the bathroom.”

Jennifer Pallian, BSc RD, registered dietitian and food scientist at Foodess, adds that hydration is more important than hitting a target, as it can differ from person to person. “Maintaining adequate hydration levels, rather than simply meeting a numeric intake goal, may play a protective role in preserving cognitive function as people age,” she explains.

Jennifer Pallian, BSc RD

Maintaining adequate hydration levels, rather than simply meeting a numeric intake goal, may play a protective role in preserving cognitive function as people age.

— Jennifer Pallian, BSc RD

Drinking 13 Cups of Water Every Day

Curious to see how feasible this goal was, I decided to give it a try for a week.

Day 1

This was a Saturday, and I woke up with a slight hangover after enjoying a few drinks the night before. It was the perfect opportunity to begin the experiment, and I was eager to quench my thirst with a glass of cold water.

Before I touched any coffee, I had my first 2 cups of the day. I had to run a couple of errands, so I drank another 2 cups while getting ready.I then bought a bottle of water at the store while I was out, and when my girlfriend wanted to sit down somewhere for a while, I ordered a glass of water rather than a hot drink or a soda. 

Once we got back home, I was almost halfway through my daily quota. I figured that being at home for the rest of the day would make things easier, and I was right.

I had a relaxing evening, and decided that every time I went into the kitchen, I’d pour another glass of water. I had my last glass of water at 11 p.m., about an hour before I went to sleep.

While I didn’t notice any effects after just one day, I definitely felt a sense of achievement in actually drinking 13 cups. 

Day 2

I woke up earlier than I usually do on a Sunday, and let myself have a coffee before switching up and having a cup of water.

I had another cup of water before going grocery shopping.It was warm outside, so I bought a bottle of water (roughly 2 cups) from the supermarket and sat down to enjoy it before heading back home. I drank another cup before going to the gym, where I drank about 2 cups.I had a protein shake followed by another cup of water when I returned, and then followed a similar pattern to the previous day.

I didn’t have anything else to do for the rest of the day, so I tried to make myself a cup of water whenever I went to the kitchen, if I didn’t already have one on the go. I made sure I had a glass of water with my dinner, too. 

Day 3-4

I didn’t feel as grumpy as I usually do on a Monday morning.

Working from home, I found it relatively easy to keep on top of my water intake—I went for a haircut over lunchtime and went for a run in the afternoon, but other than that, I was at my desk with a glass of water by my side almost at all times. 

This was the first day I thought to check my urine color, too. I thought that after a couple of days of drinking water, it might be quite pale, and I was right. While I don’t exactly make a habit of checking the color from day to day, it has definitely been a darker yellow in the past.

Tuesday was more of the same. I was drinking water throughout while at work, and felt as though I was getting into the habit of refilling my glass on a regular basis, particularly after meals.

I was going to the toilet more regularly, but by the same token, I was beginning to feel mentally and physically fresher, not as sluggish.

Because I work at my computer and then I’ll also be scrolling social media and messaging friends on my phone, my screen time statistics don’t look the best. I sometimes feel a headache coming on toward the end of the workday as a result, but I realized on Tuesday that I hadn’t had a headache so far that week. 

Day 5-6

Well into the experiment on Wednesday, I had quite a busy weekday, so I had to be mindful to meet my water consumption goals.

I kept things up regularly in the morning before heading to the gym at lunchtime, where I refilled my water bottle twice, and then had to walk into the city center to run a couple of errands before I saw my therapist mid-afternoon.

Between the gym and therapy, I didn’t fit any water in, and, with it being one of the warmest days in the UK for some time, I could feel a headache brewing when I left my therapist’s office—even though I had a glass there. 

I went to see a movie with some friends in the evening, and we grabbed food beforehand. I’d usually get a beer or a soda, but I opted for water with my meal, and I finished the last of my cups at home before bed. Needing to go to the toilet more often than usual in the movie was slightly annoying, but didn’t bother me too much. 

I remarked to my therapist that I’d been having the best week, mentally, that I’d had in some time. At the time, I didn’t connect this to my increased water intake, but reflecting afterward, I realized that there might be a connection.

Thursday was no different from the start of the week, really. I noticed that I was instinctively drinking more water with the weather being warm, and I enjoyed having a glass by me at my desk. 

It also struck me that I was snacking on unhealthy foods less frequently. Particularly in the evening, I notice myself snacking on junk food, but drinking water stopped me from feeling tempted to run to the store.

Day 7

I couldn’t believe it was Friday—and the final day of the experiment—already. I was used to enjoying my 13 cups of water, even if it sometimes felt like a lot of fluid to get through.

Throughout the week, it had made me feel fresher and, by and large, put me in a better mindset. I kept up the habit throughout the day, and, to be honest, if not for writing up this article, I’d have forgotten it was an experiment. It became a new normal quite quickly. 

The experiment is also more practical than other experiments I’ve tried. You don’t need anything fancy: just a faucet and a glass or bottle.

All this made me think that I might not need as much water as the average man. But that said, I also go to the gym or run about five or six times a week, so it might all even out. 

How Do I Know How Much to Drink?

Per the Academy’s advice, men need about 13 cups and women need about 11. This is on top of the fluids we already get from our regular food and drink—we tend to get about 20% of the water we need from our diet without actively drinking more water itself. 

Of course, this is just a guide. Age, activity level, and overall health can all impact the amount of water you need. Adults usually need more than children, as do people who live more active lifestyles. And people who are pregnant or breastfeeding need more water. As Swaid says, “There is no cookie-cutter quantity that is ideal for every person.”

Christy Swaid, wellness mentor and nutrition expert,

Severe or chronic dehydration can lead to kidney complications, heatstroke, electrolyte imbalances, shock, coma, or even death.

— Christy Swaid, wellness mentor and nutrition expert,

People with certain health conditions may also need more or less water, too. Someone with congestive heart failure might need to restrict their intake, while someone with diarrhea or vomiting will probably need more water. 

Serious health conditions aside, if you’d like to know whether you’re getting enough water, take a look at the color of your urine. If it’s a pale yellow, you’re likely consuming enough. If it’s darker, you might need more.

Can You Drink Too Much Water?

Water intoxication is a thing. It creates a chemical imbalance in your body, and in some cases, it can be fatal. Symptoms include headache, confusion, drowsiness, nausea, and muscle weakness.

Fortunately, you’d need to drink a lot to be at risk. For the average person, drinking over 8 liters a day is probably too much, or more than about 1 liter per hour—any more than that, and the kidneys can struggle to process it. “Listen to your body and stop drinking water when you feel satisfied,” says Swaid. 

How to Drink So Much Water in a Day

Drinking 13 cups sounds slightly daunting. but there are things you can try:

I made it into a routine, making sure I had a cup of water with each meal, as well as one once I got back from the gym.I tried to alternate, too, so rather than having two glasses of diet soda one after the other, I’d have a soda and then a water. It became a habit that when I went into the kitchen, I’d also get a glass of water. 

If you aren’t a big fan of regular water, Swaid recommends infusing it with natural fruits or herbs. “Squeeze fresh lemon, limes, or oranges,” she suggests. “Add mint and strawberries or make your own favorite concoction.”