Hydration Tech is here. Do you need it?

I get it. It’s easier to drink water when it’s flavorful and always within reach. I thought I was doing pretty well, drinking the recommended 64 ounces a day of the regular stuff.

When I was sidelined with a (large, painful) kidney stone, I began to wonder where that recommendation and the general discourse around hydration came from. The number one piece of advice my urologist gave me was to drink more water. A lot more water. She recommended almost 4 liters, more than double what I thought I needed.

How could I have gotten my own hydration so wrong?

Hydration, according to science

The 8 x 8 rule (drinking eight 8-ounce glasses of water) isn’t exactly based on scientific evidence, but it’s a hotly debated piece of advice. Some sources say we need more: The U.S. National Academies of Sciences, Engineering, and Medicine recommends 1.3 gallons (3.7 liters) of water for adult men (13 cups from beverages) and 9 gallons (2.7 liters) for adult women (9 cups from beverages).

But some sources say we need less: many news organizations reported on research conducted in Science in 2022 that pointed to the idea that healthy adults need less than 64 ounces, implying that those of us with access to clean drinking water are overhydrating. But what the study really highlighted was how variable water turnover is, depending on a number of factors:

• Body size
• Sex
• Climate
• Physical activity
• Socioeconomic status (regarding access to food and clean water and the type of work you do)
• Whether someone was pregnant or breastfeeding

“There is so much conflicting advice because there really is no real recommendation,” says Melanie Betz, MS, RD, a Chicago-based registered dietitian who specializes in kidney stones.

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For example, these recommendations don’t take into account whether you, like me, are prone to kidney stones. (Because if you’ve had one kidney stone, there’s a 35 to 50 percent chance that you’ll get another one within five years.)

“For a normal, healthy person with no medical history, I think the generic eight glasses of water a day is a very good starting point,” says Betz.

The confusion can also come from what we’re measuring, such as the amount of water you need to avoid true dehydration versus the amount of water you need to feel your best.

“We definitely know about (dehydration),” Betz said. “You know, your blood sodium goes up and you get dizzy, that kind of thing. That’s defined … But there’s no definition of how hydrated you have to be to really feel good.”

So if there are no real guidelines for hydration, how can you determine what You need?

Smart hydration technology to hydrate smarter

Hydration trackers come in many forms. If the amount of water you need varies with changing factors such as physical activity or climate, it makes sense that you’ll want help figuring out what your body needs. This is especially true for older adults or people who don’t get thirsty as quickly.

My doctor’s recommendation to drink 4 liters of water didn’t take into account that I am also a long distance runner and that I still planned to train for multiple races in the summer heat and humidity. How would I adjust my hydration plan further?

Introducing new, portable hydration products that are tailored specifically to my needs.

The two products I tested are similar in size and measure your sweat and electrolyte loss during a session. The first product, Nix, is a sensor that you attach to your arm via a recyclable patch. The patch seals in your sweat and prevents it from evaporating, which in theory gives you a more accurate reading.

The other product, hDrop, is a more traditional sports band. You only buy it once, but you can imagine that more sweat evaporates.

Both the Nix and hDrop were easy to set up, requiring a quick download of their respective apps that connect to the devices via Bluetooth and a quick account creation. The hDrop app even includes a tutorial on how to set up and interpret your data. To use either device, you’ll need to start a workout in the app, as they don’t run continuously in the background.

Once your workout is complete, each app will give you a breakdown of your sweat data, including fluid loss, electrolyte loss, and sweat composition based on how much fluid you replaced during your workout. The hDrop app was a little more detailed, specifically breaking down electrolytes into sodium and potassium. It also gives users a detailed recovery plan with how much fluid and electrolytes to replace based on your workout.

I was impressed with the real-time measurements of each and the personalized recommendations based on your sweat profile. The Nix biosensor even gives you mid-activity notifications when it’s time to drink.

I learned that I lose an average of 1.2 liters of sweat per hour of running, which made me feel more justified in drinking as much as I do now. Finally, I didn’t have to guess how much to drink post-run anymore, the devices told me, and they even went so far as to recommend an electrolyte product that best matched my sweat profile.

“Hydration tracking and sweat monitoring tools like Nix or hDrop can be helpful, especially for athletes or people who need to closely manage their hydration,” says Raj Dasgupta, MD, medical reviewer for the National Council on Aging. “However, they’re not necessary for everyone and should be used in addition to your natural thirst signals,” he adds.

After following the recommendations of both devices I tested, I noticed that I was less likely to collapse and actually felt more energized after my runs. I was also less likely to need a nap (unless it was a particularly long run) and had less muscle soreness.

Other wearables coming soon promise to track your hydration as you go about your daily activities, not just during exercise. Masimo, a medical device company once seen only in hospitals, is getting into the consumer wearables market with a sports watch that includes a hydration tracker. That watch is expected to launch in the fall.

Another, Geca, tracks only hydration, continuously, all day. It promises to warn the user when they are dehydrated and provide recommendations for water intake. It is also scheduled to launch in the fall.

As for non-wearable tech, Betz recommends Hidrate Spark for the clients she works with. The insulated water bottle, created after the founder’s friend suffered a health scare, tracks water consumption and lights up to remind you to drink based on your preset hydration goals. And it integrates with Apple Watch, Fitbit and Garmin watches.

“It’s proven that this makes people drink more water,” says Betz.

More than devices

Not into experimenting and working on your health like I am? A much easier method would be to consult a dietitian, if you have access, to talk about any hydration issues you may be having. A dietitian can take all of the factors discussed above into account and help you come up with a plan. They will assess your body composition, your diet, and your medical history. They will order blood work and urine tests. Then they can help you come up with a plan for how much you need to hydrate to stay healthy.

“Everyone has different hydration needs, so it’s important to listen to your body,” says Dr. Dasgupta.

If you’re able to listen to your body to hydrate, then you probably don’t need anything special to help you stay hydrated. But if you have trouble drinking water—or getting enough electrolytes during exercise—there’s nothing wrong with getting a little help.