How wearable sweat trackers are providing athletes with critical hydration insights

New Gatorade Gx sweat patch is just part of Epicore’s vision for sweat tracking wearables
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The old adage decrees it takes ‘blood, sweat and tears’ to be the best in your athletic field. But Epicore Biosystems reckons one of those fabled fluids is much more important than the others – and the start-up has developed a patch to capture and analyse your sweat.

It has developed wearable technology to capture sweat, analyse the unique biomarkers within it and offer custom hydration recommendations based on it. The goal is to ensure athletes are drinking enough fluids – and the right kinds of fluids – at half-time to maintain peak levels throughout the game.

Epicore has been working with sports drink giant Gatorade to commercialise its technology, and later this month the pair are preparing to officially launch the microfluidic Gx Sweat Patch. It’s a single-use adhesive product that captures the slick stuff and mixes it with a built-in food dye to offer colour-coded insights based upon the volume of sweat and its biochemical makeup.

How does it work?

How wearable sweat trackers are providing athletes with critical hydration insights

Some quick image processing is done by taking a picture using a companion smartphone app to reveal sweat rate and electrolyte readings. This will show athletes what, and how much, they need to drink to give the body the fluids it needs to replenish in that moment.

“The basis of our work with Gatorade began with the idea that we could build a sports electrolyte and sweat rate monitor with a view to tracking hydration and electrolyte loss for the athlete,” Epicore co-founder and CEO Roozbeh Ghaffari tells us in an interview.

The patch has been developed further and tested at the Gatorade Sports Science Institute in Bradenton, Florida, ahead of distribution to the vast array of teams and professional, college and high school athletes on Gatorade’s roster this year. Consumers will get it in 2020, but there’s no official word on the price yet.

At all levels, the patch will be a single use item that’s thrown away (or hopefully recycled) after use. That means no cleaning, no need to replenish the reactive dye or problems with adhesive for repeat usage. However, in this climate of renewed environmental consciousness, do we really need more items containing single-use plastics from a sports drinks company?

“We spend a lot of time on the use case for this first-gen product and decided single use was the way to go,” Ghaffari says. “These [are] materials that can be dropped in a regular recycling box. We do have the capability to build in Bluetooth and NFC, but that would require a battery. In a lot of cases, the battery is the biggest driver of waste.

“From our standpoint, it’s not meant to be a device that you use every day, the way you would a Fitbit. A pack of 12 may be good enough for a season, to give you a quick snapshot at the end of the exercise, or at half time.”

It doesn’t appear consumers will get the same sports science-based insights as those in the elite sports world, though, and will simply get a hydration recommendation.

For Gatorade (owned by PepsiCo), the motivation here is quite simple. It wants to provide athletes with accurate data advising them to drink more Gatorade – specifically the custom-made Gx concentrated liquid pods tailored specifically to the individual athlete’s needs – in order to replenish hydration and electrolyte levels.

However, the arrangement with Gatorade company covers just one use of Epicore’s overarching technology; commercialisation in the field of sports performance. This gives Epicore great scope to partner with others and pursue other avenues beyond the Gx patch.

Sweat shops

How wearable sweat trackers are providing athletes with critical hydration insights

Last time we caught up with Ghaffari, the firm was at CES 2019 in January unveiling the first wearable patch that tracked skin pH through sweat, designed in partnership with the beauty giant L’Oreal.

It’s a similar deal. The plaster-sized My Skin Track pH patch from offshoot La Roche-Posay measures tiny droplets of sweat to make beauty product recommendations that can help you attain correct pH balance and ward off inflammatory responses like dry skin.

Perhaps more significantly, Epicore, which Ghaffari co-founded out of Northwestern University with Dr John Rogers (the man noted for developing flexible circuits for use in body-worn items), also has contracts with the military and is working towards early-stage clinical applications with pharmaceutical companies.

“The US Air Force is one of our biggest partners, because pilots have the same needs as athletes.” said Ghaffari, himself a founder and former CTO of the wearable tech firm MC10. “The USAF cares a lot about hydration and dehydration of the Airforce men and women and whether their cognitive and physical performance starts to dip in relation.”

This partnership could also bring about sweat and heart rate correlation that eventually trickles down to consumers, as a more holistic wellness solution that can provide insight into our stress markers.

“What if we were able to measure HR and motion together with sweat? A lot of this is under development now, but the Airforce is interested in a single use sweat unit which then couples with a reusable HR sensor, so those two pieces together team up to form a system that gives you physiological and sweat tracking all in one.

“[Elsewhere] we’re also looking at the glucose, lactate and cortisone levels revealed that are native to sweat samples. As we push the tech forward, we’re hoping that provides a roadmap to partnering up with other organisations in the future.”

The future is sweaty

Overall, Epicore’s sweat-centric empire is just getting started. On a base level dehydration affects our performance not only when exercising, but our performance at work, or even when trying to sleep. The company is betting on consumers embracing biochemistry as the next major metric beyond steps, heart rate, sleep tracking and heart rate variability, as overall wellness indicators.

“Step counting is fairly widely adopted, and people understand heart rate, but biochemistry and metabolics is the next big step. With sports, it gives us a good area to focus on because of the existing maturity in data around sweat biomarkers, and what’s happening at the dehydration level.”

Basically, Epicore is banking that sweat tracking is the future and antiperspirant makers should be, well, sweating on theirs.

Epicore will be showcasing the Gx Sweat Patch and other next-gen wearable devices at the WSJ Future of Everything Festival coming up on May 20-23.


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Chris Smith


Chris has more than decade of experience writing for the UK's foremost technology publications including TechRadar, T3 and more.

 A freelance journalist based near Miami, Florida, Chris has written for Wareable since its inception in 2014. From reviews of the latest fitness devices, and in-depth features on bleeding-edge wearable devices, to future-gazing interviews with some of the industry's brightest minds, Chris covers the lot. He also writes about sport for The Guardian and is the author of many technology guide books, while also dabbling in film, music, beer, travel and political commentary.

When he's isn't smashing away at the keys of his MacBook, Chris can be found at his favourite craft breweries, dangling his rod in the warm waters of the Florida Keys, or exploring the Shropshire countryside.

You can follow his on Twitter but beware, it's mostly sporting and political hot takes, occasionally interspersed with tech-based tweets.

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