This wearable hydration sensor tracks your sweat loss as you exercise, and will soon sync with your Garmin watch

FLOWBIO S1 hydration tracker
(Image credit: FLOWBIO)

London-based start-up FLOWBIO has launched into the wearable health tracker market with the S1, a new hydration sensor for triathletes, cyclists and runners which the company claims is the most accurate device of its kind yet.

All runners and cyclists know how important it is to remain properly hydrated, but sometimes it’s too easy to get so caught up in the race you start to ignore what your body’s telling you. That’s when you need an electronic pal to give you some advice instead.

FLOWBIO S1 hydration tracker

The FLOWBIO S1 has a stated battery life of 100 hours (Image credit: FLOWBIO)

You wear the FLOWBIO S1 against your skin, clipped onto a heart rate monitor (it doesn't matter whether the monitor uses electrical or optical sensors). It measures water and sodium losses in real time, passing the data to its companion S1 Companion App, which uses an advanced algorithm to build a personalized, actionable hydration profile, presenting recovery, preparation and in-session hydration plans for optimal performance.

The S1 is already being used by used by elite athletes such as the EF Pro Cycling team and the British Olympic champion triathletes Alistair and Jonathan Brownlee.

However, while the S1 acquires data live and in real-time, the device doesn’t currently stream live data to your Garmin watch, but FLOWBIO anticipate launching this feature in the summer.

FLOWBIO S1 hydration tracker

“Sweat is data”… not the catchiest advertizing tag line we’ve ever heard (Image credit: FLOWBIO)

Stefan van der Fluit, CEO and co-Founder of FLOWBIO, says: “Wearable technology for endurance sports athletes has come a long way and yet, until now, anyone without regular access to a lab and a knowledgeable sports scientist has had to rely on estimations based on body weight. Sweat rates between athletes of a similar weight can vary significantly and that’s before you consider additional factors such as activity intensity, air temperature and humidity. Following significant research, development and sweat, we’re incredibly proud to present the S1 as the solution for athletes serious about their performance, providing accurate, athlete-specific hydration insight.”

As for accuracy, the company claims on its website: “Our latest data has indicated that we are 90% accurate in lab based conditions. In the field we achieve accuracies up to 83% for our sodium with as little as 23mg difference (that is six times less than a pinch of salt). Our fluid loss is 73% accurate with as little as 250mL difference to in-field gold standards.”

FLOWBIO S1 hydration tracker

You wear the FLOWBIO S1 against your skin, clipped onto either a chest or optical heart rate strap (Image credit: FLOWBIO)