How to Actually Stay Hydrated

May 20, 2024 8:00 AM EDT

For about 30 summers, Mindy Haar worked as the head lifeguard at a sleepaway camp in the Catskill Mountains. The teenage lifeguards under her charge wouldn’t always remember to drink water, so she remembers constantly nudging them to guzzle more H2O. The reminders worked. “I don’t recall any of my staff becoming dehydrated,” says Haar, who is now chair of the department of interdisciplinary health sciences at New York Institute of Technology.

Even if you’re not a lifeguard on duty under the blazing summer sun, staying hydrated is essential for virtually every function of the body. “Properly hydrating our bodies is crucial for them to work properly,” says Melanie Betz—aka “the kidney dietitian”—who regularly educates patients and health care professionals about the importance of hydration. “Drinking enough fluid can help you feel your best, and may even help stave off some chronic diseases,” she says.

Dehydration can negatively affect many organs and body processes, with the most extreme cases leading to delirium, weakness, or death. Being slightly dehydrated is no good, either: “Even a small amount of dehydration can begin to impact our cognitive abilities, balance, and physical performance,” says Betz. (One study found that cognitive impairment starts to become noticeable when you lose 2.8% of your body weight in fluid—which can happen when you do high-intensity exercise without drinking more water.) Plus, hydration plays a “huge role” in kidney and heart function, Betz says, as well as for your gut health (as anyone who’s ever been constipated can attest.)

Here’s what to know about how to stay hydrated—even if you don’t love water—and how to avoid common hydration mistakes.

What does it mean to be hydrated?

Being hydrated means that you’re providing the body with adequate amounts of fluid to replace what’s being lost on a daily basis. “As we lose water through breathing, perspiration, urine, and bowel movements, our water supply must be constantly replenished,” says Haar. Since humans are only able to produce small amounts of water and have limited storage capacity, water must be consumed daily from fluids and foods to replace losses. That’s why water is essential for life.

How can you tell if you’re dehydrated?

One scientific analysis published in 2019 found that only 25-30% of U.S. adults are well hydrated. The best way to tell if you’re among them is to check out a urine color chart (a tool backed by research, by the way). Still, experts warn that vitamins present in your urine and the lighting in your bathroom can impact the sensitivity of these color charts.

How much water should you drink each day?

There’s no Recommended Daily Allowance (RDA) for water. This is because hydration needs can vary dramatically among individuals depending on factors like gender, activity level, diet, environment, and medical history. You may remember the golden rule of water as eight eight-ounce glasses a day—and while that may be an acceptable amount of water for some, it may not be adequate for everyone, especially if you’re not eating enough fiber-and-water rich foods.

In lieu of an RDA, the National Institutes of Health’s Food and Nutrition Board has established an Adequate Intake (AI) for fluid, which is used when there isn't enough evidence for an RDA. The AI for fluid is 2.7L/day (91 fluid ounces, or about 11 cups) for women and 3.7L/day for men (125 fluid ounces, or about 15 cups). Recent research roughly aligns with these guidelines.

The AI guideline takes into account hydration you may get from all beverages—not just water—so juice, coffee, tea, fruits, vegetables, and broth all count. We typically get about 20% of the water we need from food and the other 80% from fluids, Haar says. Thus, women need about nine cups of fluids, and men need about 13 to maintain adequate hydration.

The best hydration sources beyond water

Most fluids (no, not alcohol) count no matter where you get them. “Certainly, water is best, but fluid from coffee, tea, and other beverages all helps hydrate your body,” says Betz.

For health reasons, however, people should avoid one category of beverages: sodas and other sugar-sweetened beverages. While they’ll technically hydrate you, “drinks like regular soda, lemonade, sweet tea, or punch add quite a bit of added sugar and are associated with heart disease and some cancers,” says Betz.

Plus, “soft drinks with added sugar can add hundreds of empty calories to daily intake,” says Haar. Haar and other experts also recommend steering clear of diet soda due to the potential dangers of artificial sweeteners.

Here are some of the most hydrating foods and drinks beyond water, according to experts:

Milks

Skim or low-fat dairy or plant-based milks are 90% water, while also supplying calcium and protein.

Water-filled fruits and vegetables

Incorporating more fruits and vegetables into your diet can help you meet your fluid goals and other nutrition benchmarks for fiber, vitamins, and minerals. Water content for fruits and vegetables varies dramatically, but watermelon, cantaloupe, strawberries, spinach, cabbage, celery, lettuce, and squash are all at least 90% water.

Electrolyte drinks or mixes

For a hydrating drink, Lexi Moriarty, a sports dietitian in Westfield, N.J., loves a salty sports drink or mix. Electrolytes, including sodium, are lost in sweat; when they’re replaced, they can help more efficiently hydrate the body by pulling water into cells, she explains.

Non-athletes may be better off saving their money on electrolyte-infused beverages, and should avoid drinks or powders with added sugar. “If your exercise session is under one hour, water will suffice,” says Haar. If you work out for over one hour, you could opt for a sports drink—but drinking water and eating a piece of fruit, like a banana, will replenish lost electrolytes just as well, she says.

How to drink more water without really trying

Almost everyone can benefit from drinking more water. Take, for example, the distance runner Moriarty recently worked with who was experiencing daily bloating and constipation. After conducting perspiration and dehydration testing, Moriarty discovered that because he was such a heavy sweater, he was only meeting about 60-80% of his hydration needs on a daily basis. “We bumped up his fluid intake, and this alone helped to improve his constipation and some of the digestive discomfort he was experiencing,” she says. “Sometimes it really is just that simple.”

Increasing fluids isn't easy for everyone. For some, it’s a struggle to hit even what Betz calls the “good starting point” of six-to-eight glasses of water a day. But there are some strategic ways you can drink more water.

Zhuzh up plain water

Although most of the fluid you drink should be water, a lot of people find it boring, says Betz. That’s why she recommends mixing things up by also drinking water infused with fruits (like a squeeze of lemon or lime) or herbs. Betz is also a proponent for sparkling water, as long as it’s unsweetened.

Fill a glass before bed

Moriarty fills up a 24-ounce glass of water before bed every night. “I usually only drink a few sips before heading to bed, so I make sure to finish the cup within 30 minutes of waking up,” she says. “This helps me get the day started on the right foot and makes it easy for me to hit my hydration goals throughout the day.”

Use a drinking vessel you actually like

One way to ensure you get enough fluids is to have on hand a vessel that’s practical and portable. Buzzy hot and cold drink containers like Stanley and Owala “give no excuse for not having necessary fluids readily available,” says Haar. (And using your own bottle is great for the environment.)

Haar uses a logo cup her school gave out as a holiday gift a few years back. “Not sure if it’s the one that keeps beverages the coldest or hottest, but I like the size and shape, and my reusable extra-long metal straw fits perfectly,” she says. Since you’re more likely to drink from a container you enjoy using, you may want to experiment with various water bottles, insulated cups, and mugs to see what works best for your lifestyle.

Set mini goals and track them

First, establish a concrete objective. “I’m going to drink more water today,” isn’t as effective a game plan as “I’m going to drink 80 ounces of water today.”

“We are more likely to hit a goal when we have a specific number in mind,” says Betz, who suggests setting "mini goals" throughout the day to help prevent getting to 6 p.m. and realizing you haven't had any water. “I usually have a set amount I want to drink by 10 a.m., then 3 p.m., and then by bedtime,” she says.

“Smart” water bottles like the Hidrate Spark, which track your fluid intake and remind you to drink by lighting up and sending smartphone alerts, may also help. Though the research was conducted in people with kidney stones, a 2022 study sponsored by the company found that people drank an average of 16 more ounces per day using this technology compared to people who were just advised to "drink more.”

Don’t make this hydration faux pas

Betz says one of the most common mistakes she sees people make in her practice is drinking all or most of their water at the end of the day. “It is easy to get caught up in your day and realize at 7 p.m. you didn't drink anything,” she says. But when you guzzle a lot of water at once, you end up losing most of it via urine shortly after, and it doesn’t change the fact that your body has been dehydrated all day. “It is ideal, as best you can, to space out your fluid intake,” she says.

“Many people wait until they feel very thirsty before drinking,” echoes Haar. “Drinking throughout the day can promote optimal hydration as compared to waiting until thirst is felt.”

A note about drinking too much or too little water

Health care professionals caution that drinking a lot of water or not enough water could be especially dangerous for certain people. “Those with advanced liver, kidney, or heart failure need to limit how much fluid they drink,” says Betz. On the other end of the spectrum, she says, people with kidney stones, polycystic kidney disease, or chronic urinary tract infections may have higher fluid needs than the general population. If you fall into any of these categories, always talk with a trusted care provider about the right amount of water intake for you.

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