Key Benefits

• Real-time measurement of sodium and fluid loss.

• Easy to action personalised hydration plans, every day.

• Validated precision trusted by Olympians, Ironman Record Holders & WorldTour Riders.

• Integrates with leading training platforms.

• Long-lasting 100-hour rechargeable battery.

• No App subscription.

The FLOWBIO Sensor is the most accurate sweat sensor available, proven to give lab-level results. It measures how much fluid and sodium you lose while you train, giving you clear guidance to consume what your body needs.

Linked with the FLOWBIO App, the Sensor shows what to drink, when, and how much. The Hydration Planner creates simple, session-specific plans based on your workout length, intensity, the conditions you train in - plus your physiology.

After each session, log what you consumed and select your favourite electrolyte brands including Precision Fuel & Hydration, SiS, Maurten, and others to keep your strategy personalised.

The Sensor is easy to use. Wear it on your upper arm with the included strap, or attach it to your chest strap. With a 100-hour battery, USB-C charging, and links to Garmin, Zwift, Wahoo, and Coros, it works smoothly with your current setup.

A Garmin, Coros, Zwift or Wahoo device is required for use.

TECHNICAL SPECIFICATIONS:
Measures Sweat Loss (L/HR).
Measures Sodium Loss (MG/L).
Skin Temperature Sensor.
100 Hour Battery Life.
FLOWBIO arm strap provided.
Can be worn on existing HR chest strap.
USB-C charging.
Predictive hydration planner for cycling & running.
Works with Garmin, Zwift, Wahoo & Coros.
Compatible with IOS & Android.
Rehydration recommendations from your favourite electrolyte brands.

Hydration is vital for performance, yet most athletes still rely on guesswork.

Sweat rate and sodium loss aren’t fixed. They significantly vary from person to person and from session to session for the same individual. They shift as a function of effort, temperature, and physiology — making averages unreliable. FLOWBIO removes the guesswork with the world’s most accurate, fully reusable sweat sensor.

This technology analyses your sweat profile in real time and combines it with intensity and environmental data to deliver clear, personalised hydration recommendations. By tracking these trends session after session, you build a strategy based on your physiology — not estimates or trial and error. The result: smarter training, faster recovery, and fewer hydration-related performance dips.

FLOWBIO was born from the shared vision of Stefan van der Fluit and Giovanni Rovere: to use wearable devices to unlock real-time insights into the human body. In 2021 FLOWBIO marked their first step, pioneering sweat analysis with an early prototype and earning UCI approval. By 2023, their technology became the world’s first fully reusable sweat sensor, crafted in London with advanced temperature and ambient sensing. In 2025, the FLOWBIO Sensor arrived, refined through global validation and quickly adopted by elite cycling, running and triathlon teams. Today, FLOWBIO helps athletes personalise hydration, train smarter, and push the limits of performance.

With our Healf Curation Process, we do the work for you. Shop with confidence knowing that every item has been tried, tested, and curated for you.

Learn more about each step—Brand Discovery, Expert Validation, and Community Testing—here.

1. Wear the Sensor
Attach the FLOWBIO Sensor to your existing chest or arm heart rate monitor before your session. As you train or race, it continuously measures your sweat in real time.

2. Capture Sweat Data
The sensor captures and analyses both sweat rate and sodium concentration in real time.

3. See Your Results in the App
Post session your sweat data syncs instantly with the FLOWBIO app, giving you clear, personalised insights — not generic advice.

4. Act on It
Use your results to know exactly how much fluid and sodium to replace, adjust your hydration to match the day’s conditions such as heat, effort, or environment, and recover faster so you feel stronger going into your next session.