Does Coffee Affect Your Hydration? Clearing Up Confusing Dehydration Myths [CNET]

Experts debunk popular hydration myths, including that water is the best way to hydrate.

Fun fact: A majority of the human body is made up of water — up to 60% water, to be exact. Hence why it’s important to stay hydrated. Staying hydrated is especially important if you work out vigorously and during the hotter months when you’re more prone to sweating and dehydration if you don’t properly replenish liquids and nutrients. There are various ways to stay hydrated that you may not have considered, but common with wellness content, there is a lot of misinformation out there on hydration. 

We are clarifying these fallacies once and for all with the help of experts. These are the hydration myths you need to stop believing.

Myth No. 1: Coffee is dehydrating

You’ve probably heard that coffee is dehydrating, so you shouldn’t count it toward your fluid intake. This has been proven to be false. Mayo Clinic registered dietitian Katherine Zeratsky tells CNET, “Coffee, tea or other caffeinated products are not absolutely dehydrating, especially if they are consumed regularly. The body can adjust to a certain amount of caffeine, and it has less impact on hydration status.”

Coffee is a diuretic, meaning it increases urine output and makes you take more bathroom breaks. You don’t want coffee to be your main source of hydration, so make sure to balance it out with water and other hydrating options throughout the day. 

Myth No. 2: Food isn’t hydrating

You’ll be relieved to know that another way to get hydrated is with the food you eat. By including foods like vegetables, soups and fruits in your diet, you can contribute to your hydration needs. “For the average person, increasing fruit and vegetable intake — without salt — can be helpful in improving hydration and overall health,” Zeratsky says. Keep in mind it’s harder to meet fluid intake simply by eating food because of the volume requirements.

“Focus first on drinking plenty of water and add in hydrating fruits and vegetables to help keep you hydrated,” recommends registered dietitian Marisa Moore. Zeratsky advises eating a nutrient-rich diet that is full of minerals or electrolytes. She points out that some of the best foods for this type of diet include nuts, seeds, beans and legumes, a variety of vegetables — especially green types, among others — dairy products and fruits. “These provide magnesium, potassium and calcium — all important electrolytes,” she says.

Myth No. 3: You don’t need sports drinks

There is a time and place for sports drinks, but this depends on the individual. “Athletes or active people participating in activities that are at a high intensity and greater than 45 to 60 minutes and [active people who] sweat heavily will benefit from electrolyte replacement,” says Zeratsky.

If you’re training for a race that requires you to exercise for more than an hour at a time, replenishing fluids with electrolytes and carbohydrates is important. “Sports drinks can help very active people replenish the water, carbohydrates and electrolytes they lose during intense or prolonged physical activity,” says Moore.

Zeratsky adds, “For moderate to intense activity, about an hour or greater, sports drinks can improve how a person feels and their performance.” Another way to replenish these carbs and electrolytes is by drinking beverages or eating foods that contain salt (since sodium is an important mineral we lose when we sweat) and other electrolytes.

Myth No. 4: Fluid needs are one-size-fits-all

You know the old adage that you need to drink eight glasses of water a day? This isn’t necessarily true. Both Zeratsky and Moore point out that your hydration needs can vary daily. “Fluid needs depend on your body size, health status, activity, climate (including altitude) and age,” explains Zeratsky. One surprising fact that Moore shared was that you lose water by simply breathing and talking. “If you will be talking more — especially during a physical activity — you’ll need to prepare with more water,” she says. 

Other factors you need to consider are health-related conditions that can affect how much fluid you should be drinking. “Changes in medications, age and health-related conditions like pregnancy and lactation can impact your thirst and require more fluids,” explains Zeratsky.

Myth No. 5: Thirst is a good indicator that it’s time to drink water

This is partially true, but Zeratsky mentions that people often ignore internal cues that they are thirsty, and by the time they reach for water they have fallen behind on their daily fluid intake. Moore says, “Don’t rely on thirst as a measure of hydration because feeling thirsty is often a sign that you are heading towards or are already dehydrated.” Zeratsky explains that a good starting point is to aim for eight 8-ounce cups or 2 liters of water daily. “From there, monitor how you feel when you adjust your water intake and notice the color, amount and frequency of urination,” she says.

You should be drinking water early and often, according to Moore. “This means drinking water in the days leading up to activity and also drinking throughout,” she says, adding that you should especially take this to heart if you’re going to be working out in hot environments. 

Moore also suggests carrying a refillable water bottle with you to stay hydrated, going on to say, “If plain water is not your favorite, consider adding flavor like fresh fruit, cucumber or a sprig of mint for flavor.”