We all know how important water is for our well-being but it can be difficult to know when we need to top up our levels of H20. U.S.-based BSX Technologies came up with the world’s first hydration monitor that measures a person's water levels in real-time and  notifies the wearer when to drink. The LVL (pronounced "level") bracelet uses special red light technology to measure the body’s water content and other physiologic activities. The device, successfully funded over Kickstarter, can also track a wearer’s heart rate, sleep quality, activity (steps) and calories burned. Dustin Freckleton, founder and CEO at BSX Technologies, explains why staying hydrated isn’t always as easy as it sounds.

How did you come up with the idea for the LVL bracelet?

Three weeks before my 25th birthday I had heat stroke that was caused by dehydration. I was lucky because as a medical doctor I was trained. I knew the warning signs as soon as they appeared which allowed me to immediately respond. But months of rehab and therapy followed before I could eventually claim a full recovery and this experience taught me that the beauty of the quantified self movement is not simply that we now know more about our bodies, it’s that we are measuring the right things at the right time, so that we can do something about it when it counts.

How does it work?

LVL directly measures the water content in the body using our patented red light technology. This red light is shined into the body using specialized consumer grade LEDs. As the light passes through the body, each wavelength is absorbed and reshaped in a unique way that allows us to generate a spectrographic "picture" of the water content and other physiologic activities happening in the body at that point in time. It is very similar to what happens when visible light hits our eyes, allowing us to see.

What else can LVL measure apart from dehydration?

It also measures heart rate, calories, activity, and sleep quality.

How important is it to be hydrated?

When we’re properly hydrated we feel better, think better, look better, we just are better. Studies have shown that 75 percent of the population is chronically dehydrated. This goes up to 90 percent plus in elderly populations where the thirst drive is not as strong and access can be more difficult. And because our bodies are mostly water, it’s so important to stop it before it ever happens. Even a 1 percent difference affects you in a huge way.

But people can just drink when they feel thirsty…

The problem is that our thirst drive doesn’t kick in until it’s too late, when we’re already dehydrated. That drive isn’t sensitive enough to tell us when to drink or how much to drink, in order to reach optimal hydration. Though it's true that you should always drink when you're thirsty, the absence of thirst does not mean that you should stop drinking. The presence of fats and sugars in our diet can significantly depress the thirst drive. Even athletes are not immune: recent studies have shown that during exercise, athletes who drink at will only consume 30 to 70 percent of the actual volume lost. Furthermore, scientists at Purdue University have shown that people seldom drink when they're thirsty, instead they simply drink when they eat.

Why is that?

It is a more difficult question and many very good theories exist. But due to the complexities of the hydration equation (gender, body mass, age, BMR and sweat rate, temperature, altitude, humidity, exercise, amount of fluid consumed through food, etc) it is a very difficult and individualized question to answer. This is why generalized recommendations of eight glasses of water per day are so inaccurate and real-time measurement is so important.

-Dmitry Belyaev