guy drinking from water bottle while working

How to Hydrate Fast: Rehydrate in a Hurry

Essential minerals are key to eliminating dehydration.

Fast Facts

  • You need to hydrate fast if you’re suffering symptoms of dehydration like fatigue, extreme thirst, and muscle cramps.
  • Mild dehydration can be relieved in as little as 10 minutes.
  • Hydrating fast helps you restore lost fluids and minerals.

Sweating like a pig? Don’t pull a Bear Grylls. While the British adventurer gained notoriety for rehydrating by drinking his own urine, there are far better ways to hydrate fast. 

Dehydration sets in when your body loses more fluids than it’s taken in. More than half of the human body is made of water, so even a small deficit can be harmful. Losing as little as 1.5 percent of your body’s water can lead to fatigue, thirst, and a mouth that feels as arid as the Nevada desert.   

The best way to rehydrate depends on how much fluid you’ve lost. For mild dehydration, drinking water and electrolytes—essential minerals like sodium, chloride, calcium, magnesium, phosphorus, bicarbonate, and potassium—can relieve symptoms in as little as 5 to 10 minutes, according to the Cleveland Clinic.

If you’ve developed a headache and muscle cramps, you’re veering into moderate dehydration territory. Drinking fluids can help you hydrate quickly, but if you start to feel confused, faint, or struggle to breathe, get to an urgent care or ER, stat. You may need IV fluids, says Susan Greene, ACE certified Nutrition Specialist, health coach, and personal trainer. 

You should start to feel better within about 45 minutes of getting IV fluids, but it can take several hours for you to feel back to normal, and up to three days to completely replenish lost fluids, Greene says.

About the Expert:

Susan Greene, CPT, CHC, is an ACE certified Nutrition Specialist, health coach, and personal trainer in Hanover, Massachusetts, who coaches her clients on fitness and hydration.

Signs of Dehydration

If you’re searching for how to hydrate fast, you probably already know you’re dehydrated. In case it’s in question, here’s what to look for.

Urine color

Urine is a good indicator of your hydration levels. If you’re well-hydrated, your piss should be anywhere from pale straw yellow. If your urine becomes a brown-ish color, that’s a clear sign of dehydration.

Conversely, if your pee is clear, you could be overhydrated which may be lowering your salt and electrolyte levels. In that case, pump the brakes and stick to the basic rule of thumb of 64 fluid ounces of water a day.


Feeling tired often leads to grabbing a cup of coffee to boost  your energy, but it could also mean that you need to be consuming more fluids overall. 

Fatigue sets in when you don’t have enough water in your system to support healthy functioning, says Greene. “As the body becomes distressed, your energy depletes. The result is extreme lethargy.”

Dehydration fatigue is different from the kind of tired you feel after a long day at the office. When you’re dehydrated, you lack the power to move, you feel jittery and anxious, and your muscles are so tired all you want to do is sit down, according to Greene.

Extreme thirst

While it may be a myth that thirst is a slam-dunk sign of dehydration, a bone dry mouth is cause for concern. Excessive thirst is a red flag that your body is low on water.

Decreased cognitive functioning

When you feel fatigue kick in, don’t be surprised if cognitive function dips as well. Dehydration is linked to deficits in short-term memory, vigor, attention, and reaction, all of which improve with hydration supplementation (1).

Muscle cramps

“Individuals suffering from mild dehydration will feel a tightness in their lower extremities for around 10 to 30 seconds,” says Greene, likening it to a Charley Horse. “Light stretching and plenty of fluids can help to eliminate the cramp, but it can last longer with more severe dehydration.”

How to Hydrate Fast

To rehydrate stat, you need to replace the fluids and minerals quickly. Particularly the latter.“Electrolytes are the most effective way to get your fluid balance in check,” says Greene. 

Electrolytes help to balance fluids as well as successfully transport nutrients around. Sodium helps balance fluid, potassium can help with cramping, and magnesium regulates muscle function (2). 

Here are your best options for getting the fluids and minerals your body needs ASAP, and any considerations you might need to make if they’re your only option.  

Plain water

Bottled or from the tap, water is a cheap and easy fix for mild dehydration. Men are typically advised to consume approximately 11-13 8 oz glasses of water, whereas women generally require around 10 8 oz glasses of water as their recommended intake.If you’re moderately or severely dehydrated, it won’t cut it. “Plain water doesn’t have the minerals needed to overcome the fluid loss,” says Greene.

Oral rehydration solutions

An oral rehydration solution (ORS) is a specialized formula of water, sugar, and electrolytes—specifically sodium and potassium—designed to replenish the body’s fluid levels. The most popular oral hydration solution is Pedialyte, but powdered solutions like DripDrop are also available.

Oral rehydration solutions are the most effective way to hydrate fast since they contain electrolytes your body has been deprived of, according to Greene. They have also been promoted to boost exercise recovery and promote and treat hangovers. 

One study of healthy male cyclists compared the fluid balance efficacy of an oral rehydration solution against sports drinks and water: Oral rehydration solutions were more effective at restoring fluid balance during recovery than the others (3).

Sports drinks

Gatorade and Powerade are popular hydrating options. “They are great for athletes because they contain electrolytes and other key ingredients that help you recover from the physical demand of strenuous activity,” says Greene.

The downside? Sports drinks can pack a lot of added sugar, which can lead to weight gain, high blood pressure, and inflammation. So unless you’re an athlete, you might want to stick to lower-sugar options like Gatorade Fit

If you are an athlete, aim for 30 to 60 grams of carbs per hour in a 6 to 8% carb-sodium solution in 100 mL of fluids for activity greater than 60 to 70 minutes. Preferably this solution should be consumed every 10 to 15 minutes. This is especially important during high-intensity physical activity in hot and humid conditions (3).

Coconut water

“Coconut water replenishes electrolytes since it contains those vital minerals, but has less overall amount than an oral rehydration solution,” says Greene. “Since the amount of electrolytes varies, it’s inconsistent for hydrating effectively.” Still, it might be beneficial for lower intensity exercise.

Electrolyte drinks

Electrolytes are essential for balancing fluid levels. They can also help with injury prevention and proper organ function (4). 

Electrolyte drinks vary heavily based on your needs and preferences. Most come in powder form, and easily dissolve into a water bottle on-the-go. Some—like Liquid IV—intentionally contain sugar which can help with replenishing energy during or after a workout, while others—like LMNT—avoid sugar to cater to the keto crowd.

Greene recommends Smartwater—she likes the simple formulation: just distilled water and electrolytes. “My favorite option is Nuun, a tablet packed with key electrolytes which mixes easily into 16 ounces of water.” 


Feeling hungry? Both fresh and frozen fruits and vegetables make a perfect hydrating snack due to their high water content. Look for fruits like watermelon, cucumbers, grapefruits, and peaches, which have a high water content.

man drinking water on the beach


If you can stomach a full glass of dairy, milk is surprisingly hydrating and nutrient-dense. Milk naturally contains high concentrations of electrolytes (5). Research suggests both skim and low-fat milk can rehydrate you just as well as other popular sports drinks, while providing a quality source of protein for kickstarting muscle repair after a workout (6). 

That said, milk obviously isn’t the best option if you have a dairy allergy or lactose intolerance. Plus, since it can upset your stomach it’s best to steer clear if you’re already dealing with gastrointestinal symptoms of dehydration like diarrhea or vomiting (7). 

Tea or coffee

In moderate amounts both coffee and tea can help you stay hydrated, however dose matters. Tea and coffee both contain caffeine, which is a diuretic (meaning, it causes fluid loss) in high amounts (8). Caffeine becomes dehydrating at 250 to 300 mg or more (9)—about two to three cups of coffee or five to eight cups of tea. If you’re working out (especially in the heat) it’s important to take supplements that typically contain high amounts of caffeine—like pre-workout—into consideration.

How Much Water Do You Need?

Drinking 8 ounces of water is an old myth. The Adequate Intake (AI) for total water (which includes water, other beverages, and food) to prevent dehydration is 3.7L for men—which shakes out to about 15 to 16 cups—and 2.7L for women (11 cups) (10).

Can You Rehydrate Overnight?

Not unless you wake up every hour to sip water. “It’s ideal to keep up with your recommended amount of hydration throughout the day in order to avoid excessive drinking right before bed,” says Greene. “While there isn’t a miracle to immediately hydrate overnight, being efficient with your water intake will work.” Go to bed well hydrated, your morning urine should be that straw yellow color, according to Greene. 

For athletes, the ISSN recommends consuming 500 milliliters (around two cups) of water or sports drink the night before a workout, 500 milliliters upon waking, and another 400 to 600 milliliters roughly 30 minutes before you start working out (11).

What Causes Dehydration?

Dehydration is caused by not drinking enough fluid or losing more fluid than you take in. Fluid loss can happen through sweating, vomiting, urine, and diarrhea—which can be influenced by a number of factors including exercise, severe weather or conditions, health status, sickness, toxicity, and more.

Frequently Asked Questions

How can you hydrate fast at home?

If you’re mildly dehydrated, plain water is always an easy and cheap option. However, you’ll often need to replace electrolytes, too—which help with overall fluid balance. To replace fluid and electrolytes, oral rehydration solutions, electrolyte powders, sports drinks, milk, coconut water, fruit, and even small amounts of coffee and tea are solid options. 

In cases of severe hydration—especially if you’ve been exercising in extreme temperatures, have a high fever, or continued symptoms like diarrhea or vomiting—check with your doctor about which hydration solution is best for you. In some cases, a fluid IV administered by a health care provider may be in order.

How long does it take to rehydrate your body?

When replacing fluids, your body starts to absorb water within five minutes, and full absorption can take anywhere from 75 to 120  minutes (12). But it depends on what type of fluid you take in, how much you drink, how dehydrated you were to start with, and whether the cause of dehydration—like diarrhea—has cleared up.

What is the best way to rehydrate in the morning?

Drink water. While you can start your day with any hydrating beverage like milk, coconut water, or hot water with lemon to rehydrate first thing (yes, even coffee or tea), plain ol’ water is the easiest and cheapest way to start your day on a hydrating note.

The Bottom Line

The fastest way to hydrate is with an oral rehydration solution. These products are packed with a balance of water, sugar, and electrolytes—which are minerals found in your body that balance fluid levels and maintain optimal hydration. While you can hydrate fast with regular water, it’s important to focus on electrolytes.