Meet the S1: the world’s most accurate hydration sensor. No cramps, no guesswork - all for just £329.
Monitoring real-time sweat losses with the S1 prevents dehydration, helps your recovery and ensures you perform at your very best. Everyone has a unique sweat profile, losing fluid and key electrolytes in different amounts.
The S1 gives you an unprecedented understanding of your body’s hydration needs for training and race-day. It measures how many electrolytes (sodium) and water you lose in real-time.
The S1's accuracy is on par with in-field gold standards. You no longer have to compromise on ease of use and quality of data. Trusted by professionals like EF Pro Cycling and Alistair Brownlee.
We combine our unique hardware with world leading modelling to provide you with the data you need to perform.
Using patented algorithms, we accurately predict your hydration needs in upcoming sessions. Our coach provides recommendations on what you should be drinking before, during and after each session and race.
Study your previous sessions with our insights tool. We show your hydration problem areas and provide tailored recommendations on how to improve.
You can connect all of your favourite fitness apps and devices including Garmin, Wahoo, Zwift and TrainingPeaks - we’ve got you covered. The S1 communicates via ANT+ and Bluetooth.
The S1 captures your sweat and analysis its contents. Proprietary algorithms use the sensor data to estimate your sweat rate and sodium loss. The data is shown on our Companion App, offering recovery and preparation suggestions and tips to optimise your performance.
No, the S1 does not have a needle. We collect sweat through a tiny channel using the pressure exerted by your sweat glands.
The S1 measures your sweat rate and sodium loss, helping you optimise your recovery and prepare for training and events by ensuring you replace and bring the necessary fluid and electrolytes.
The battery life is 100+ hours and the device can be charged using a USB-C cable.
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 23 mg difference (that is 6x less than a pinch of salt). Our fluid loss is 73% accurate with as little as 250mL difference to in-field gold standards. If you are interested in learning more about the accuracy of the system behind the S1, you can request our whitepaper here.
The S1 is swim-friendly with an IP65 rating. However, currently, swimming won't provide sweat rate and sodium loss data as this is still in development.
We don’t charge any subscriptions or monthly costs to use the S1.
Currently, our Companion App's availability is limited to iOS.
You can exercise without your phone nearby, but for syncing the S1 and viewing your data, having your mobile device is essential.
At present, using the S1 requires a fitness tracker integrated with the Companion App. We currently support the following integrations:
While we acquire data live and in real-time, we haven't developed live integrations yet. The S1 doesn't currently stream live data to your Garmin, but we anticipate launching this feature in the Summer of 2024.
The device is entirely reusable with no single-use components. To maintain accuracy and functionality, a sporadic and simple rinse under a tap is all that's required.
Currently, data from the S1 is accessible only during cycling, running or walking activities. We plan to expand and include other sports as we grow. If you are interested in using our S1 for a different modality please get in touch here.
We provide you with the following metrics from the S1:
The S1 is designed to be worn on an existing heart rate monitor. We support both optical arm-based monitors and chest straps, offering flexibility in wearing the S1 either on the upper arm or on your back.