It’s important to rehydrate after any activity that causes heavy sweating, such as an intense workout, sauna session, or hot yoga class.
Rehydrating is also crucial for preventing the damaging effects of dehydration if you have the stomach flu or are recovering from a night of drinking.
This article discusses the signs and symptoms of dehydration and the best ways to rehydrate quickly at home.
Signs and symptoms of dehydration
Every cell, tissue, and organ in your body requires water to function.
Water helps regulate body temperature, lubricate joints, transport nutrients, remove waste, and circulate blood. That means your body can’t properly perform these functions if you’re dehydrated, which happens when you lose more fluids than you take in.
For example, you can become dehydrated from sweating, vomiting, experiencing diarrhea, or taking diuretic medications that increase fluid loss.
Certain populations are more prone to dehydration than others, including children, older adults, and people with certain medical conditions like diabetes and kidney disease.
The signs and symptoms of dehydration include:
• increased thirst
• dry mouth
• infrequent urination
• dry skin
Urine color is also a common indicator of hydration status. Generally, the paler the color, the better hydrated you are. That said, the color can change for reasons other than your hydration status, including diet, the use of certain medications, and some medical conditions.
Studies have shown that urine color is a valid indicator of hydration in children and young adults but not in older adults.
If you’re worried about your or someone else’s hydration status, here are the 5 best ways to rehydrate quickly.
While it likely comes as no surprise, drinking water is most often the best and cheapest way to stay hydrated and rehydrate.
Unlike many other beverages, water contains no added sugars or calories, making it ideal to drink throughout the day or specifically when you need to rehydrate, such as after a workout.
It’s worth noting that a variety of factors, including genetics, cause some people lose more sodium via their sweat than others. You might be a “salty sweater” if you get frequent muscle cramps with exercise or if your sweat stings your eyes.
If either of these apply to you, make sure to replace not just the fluid you lose through sweat but also the sodium, particularly after intense or long bouts of exercise in hot environments.
That said, unless you’re participating in a long, intense activity like an ultra-endurance event in a hot environment, the sodium you lose through sweat can easily be replaced through a balanced diet.
For most people, drinking water is sufficient to rehydrate. If you’re a salty sweater, be sure to replace both the sodium and fluid you lose through sweat, preferably through a balanced diet.
Coffee and tea
Coffee and tea contain the stimulant caffeine, which can be transiently dehydrating in excess amounts, as it acts like a diuretic.
However, drinking coffee and tea in moderate amounts can be as hydrating as drinking water and serve as an energizing alternative.
Caffeine becomes dehydrating only in doses around 250–300 mg, the equivalent of two to three 8-ounce (240-ml) cups of coffee, or five to eight 8-ounce (240-ml) cups of tea.
In a study, 50 regular coffee drinkers drank 4 cups (800 ml) of coffee containing 1.8 mg of caffeine per pound (4 mg per kg) of body weight daily. It observed no significant differences between coffee and water in regards to hydrating ability.
If you don’t like these beverages plain, try adding unsweetened almond milk to your coffee, or herbs and spices like cinnamon, nutmeg, or lemongrass to your tea.
Drinking moderate amounts of coffee and tea have similar hydrating properties as water. Plus, their caffeine content may give you an energy boost.
Skim and low fat milk
In addition to supplying a host of nutrients, milk has excellent hydrating properties.
Milk naturally contains high concentrations of electrolytes, which help balance the amount of water in your body.
Research has shown that skim and low fat milk rehydrate you as well as popular sports drinks after intense exercise, all while providing protein and other important nutrients.
The high quality protein in milk also makes it an ideal post-exercise beverage for kick-starting muscle repair and the rebuilding process.
Just keep in mind that consuming milk after exercise may cause stomach discomfort like bloating. Plus, it’s not an appropriate option for people who are intolerant to lactose or certain milk proteins.
Milk — namely full fat milk — might also not be a good option if you’re experiencing diarrhea or vomiting, as it could worsen these conditions.
Skim and low fat milk can be used as an effective post-workout or general rehydration beverage if you don’t have lactose intolerance or a milk protein allergy.
Fruits and vegetables
Comprising 80–99% water, fruits and vegetables make for a perfect hydrating snack.
For comparison, highly processed foods like cookies, crackers, cereals, and chips contain only 1–9% water.
Fruits and vegetables with the highest water content include:
Stock up on a variety of fresh fruits and vegetables and keep cubed watermelon in your fridge for easy and convenient access.
Frozen fruits and vegetables are just as nutritious as their fresh counterparts, and in some cases, they’re more nutritious.
It often takes days or even weeks before fresh fruits and vegetables make it to your plate. During that time, oxidation can cause nutrient loss. On the other hand, frozen fruits and vegetables are frozen shortly after harvesting, which retains most of their nutrients.
For example, one study showed that frozen green beans and blueberries contained more vitamin C than their fresh counterparts.
Try making a hydrating, nutrient-packed smoothie by combining your favorite fresh or frozen fruits and vegetables in a blender along with milk or Greek yogurt.
Due to their high water content, both fresh and frozen fruits and vegetables make a perfect hydrating snack.
Oral hydration solutions
Oral hydration solutions are specialized formulas used to prevent and treat dehydration caused by diarrhea or vomiting.
They have also been promoted to bolster exercise recovery and prevent or treat hangovers.
These solutions are water-based and commonly contain electrolytes like sodium, chloride, and potassium, as well as sugar, typically in the form of dextrose. Some commercial solutions also contain other ingredients like prebiotics and zinc.
While these rehydration drinks help replace lost fluids and electrolytes, they can be expensive.
Fortunately, you can make your own using these common kitchen ingredients:
• 34 ounces (1 liter) of water
• 6 teaspoons of sugar
• 1/2 teaspoon of salt
Combine them in a large bowl or pot and stir until the sugar and salt dissolve. You can use flavor enhancers to improve the taste if desired — just keep in mind that they may contain artificial or natural sweeteners and flavors.
Oral hydration solutions contain water, electrolytes, and sugar. You can make your own simple rehydration solution at home using water, salt, and sugar.
The bottom line
Dehydration occurs when your body loses more fluids than it takes in.
For most people, drinking water is the best way to stay hydrated and rehydrate.
Other options include coffee, tea, milk, fruits, vegetables, and oral hydration solutions.
Don’t hesitate to speak with your healthcare provider if you’re concerned about your or someone else’s hydration status.