In a world the place unmanned spacecraft have landed on Mars and synthetic intelligence can learn your thoughts, one would suppose somebody would have discovered a exact method to measure how a lot athletes ought to drink whereas exercising. Hydrating, or changing physique fluids misplaced by sweating, exhaling, and eliminating waste, is important. When 2 or extra % of physique mass is misplaced by dehydration, the physique can go haywire, with elevated cardiovascular pressure, diminished cardio train efficiency, and impaired thermoregulatory perform. After dropping 12 % of physique mass to dehydration, a human will die.
It’s uncommon for an athlete to train to the level of loss of life by dehydration. But it’s additionally odd to think about that, for such an necessary physiological necessity, many athletes depend on thirst as their definitive information to how a lot they need to hydrate throughout train. The hassle with that in-built system is twofold. By the time your mind registers that you simply want water, your physique is commonly already dehydrated. Also, it’s simple to alleviate your thirst earlier than you’ve fully rehydrated.
Outside a lab, the most correct commonplace for figuring out an athlete’s fluid loss is to weigh the nude physique earlier than and after the exercise. (For each pound of physique mass misplaced, 16 ounces of water needs to be consumed.) But that technique doesn’t assist a runner decide how a lot fluid they’ve misplaced whereas on mile 16 of a marathon.
Cyclists can depend on a GPS laptop with a drink alarm that flashes a reminder to take a swig from a water bottle each quarter-hour. Runners and fitness center rats can put on a smartwatch with a hydration sensor, like the Apple Watch, which makes use of electrodes positioned in opposition to the pores and skin to measure electrical conductance of the wearer’s sweat. This can decide the focus of electrolytes (or lack thereof) in the sweat, which helps decide the person’s hydration degree. There’s additionally a $25 gadget known as the GX Sweat Patch, marketed by Gatorade, a one-time-use biosensor that, when utilized to the internal left forearm, measures the person’s sweat fee, fluid loss, and sodium loss. When that knowledge is transferred to the companion iOS app, it operates as a tenet for the athlete’s future efficiency.
Until not too long ago, nonetheless, biosensing know-how that may analyze the content material of an athlete’s sweat to supply personalised, real-time hydration suggestions as they’re exercising has been out of attain as a result of the sensing tech hasn’t been reasonably priced sufficient to construct right into a client product.
Photograph: Nix Biosensors
In December, a Boston startup based by Harvard Business School graduate and marathoner Meridith Cass unveiled the Nix Hydration Biosensor, the first wearable sensor that guarantees to supply real-time sweat science to athletes. Cass, who can also be a former collegiate basketball participant, began interested by biosensing know-how to measure hydration after she struggled together with her personal physique’s response to warmth and humidity when coaching for marathons. “I was feeling very sluggish on some of those longer runs,” she says, “and I wondered, ‘could a hydration sensor be a thing? And would anybody find it useful other than me?’”
Nix works like this: When hooked up to the bicep (through a protecting movie on the underside of the patch, which is about the dimension of a spherical orange slice), the patch measures the sweat profile of the physique regionally, extrapolating it to the full space of the physique through algorithmic computation. As sweat dribbles throughout the electrodes on the bicep patch, the patch measures the content material of the sweat twice alongside its circulate path. By evaluating knowledge on these two areas, the sensor can inform how rapidly fluid is shifting by the physique. When linked through Bluetooth to an iOS companion app, the sensor relays hydration notifications to the telephone in intervals custom-made by the person. The level is to maintain the athlete, as they’re understanding, inside 1 % of their beginning physique mass (or 1 % of dehydration) to keep away from the nasty pitfalls that include dehydration.
