S1 Companion

Push the boundaries of your performance with the world's most accurate hydration sensor.

The S1 gives you an unprecedented understanding of your body’s hydration needs for training and race-day. It measures your water and electrolyte losses in real-time, with an accuracy on par with in-field gold standards. The S1 is trusted by WorldTour Cycling teams and Olympic Gold medal triathletes.

The S1 Companion App gets the most out of your S1 device:
- Understand your sweat composition for a session, and view your hydration recovery plan.
- 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 Coros - we’ve got you covered.