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FLOWBIO Sweat Sensor | Rental Unit

The most advanced wearable sweat sensor – available to rent.

Prevent dehydration from compromising your performance and recovery. FLOWBIO is the first real-time sweat sensor that tells you exactly what hydration you need to consume to perform at your best - every session, every race day.

  • Rent for 2 weeks for only £69
  • Real-time sweat and sodium data
  • Integrates with Garmin, Wahoo, Zwift, and COROS
  • Optional full purchase after trial
  • Free tracked returns or buy to keep

After your 2-week trial, return it for free, or pay the remaining £310 to keep the unit. If no action is taken, you’ll be charged the remaining balance automatically.

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You’ve Normalised the Warning Signs

Cramping mid-session. Hitting the wall in the final third of your race. Inexplicable dips in performance from one day to the next.

Too often, we chalk it up to undertraining, bad luck, or poor fuelling. But in many cases, it’s a hydration issue — specifically: an imbalance in sodium and fluid that’s gone unnoticed.

Despite how much we track pace, power and heart rate, sweat remains the blind spot in most training setups.

Attach the Sensor

Secure FLOWBIO to your upper arm or chest strap using the included fasteners.

Train Normally

Run, ride, or workout as usual – FLOWBIO automatically tracks your sweat.

Sync with App

Open the FLOWBIO App to review your sweat rate and sodium loss data instantly.

Return or Keep

After 2 weeks, return it for free or pay the balance to keep your device.

See FLOWBIO in Action

Watch how the FLOWBIO Sweat Sensor tracks and interprets hydration data in real time.

FLOWBIO Rental FAQs

How long is the rental period?

The rental lasts 2 weeks from the delivery date. After that, you can return it or purchase it outright.

What if I forget to return it?

If you don’t return the unit within the 2-week window, we’ll automatically charge your card £310 to keep it.

Does it require a subscription?

No ongoing subscription is required. You pay £69 for a one-off 2-week rental. If not returned, the remaining balance of £310 will be charged to your card.

Where do I wear the sensor?

You can wear the sensor on either arm or attach it to your chest strap. It’s designed to be comfortable and secure during all training sessions.

Is the FLOWBIO app free to use?

Yes, the FLOWBIO app is completely free to use during your rental. You’ll get full access to real-time sweat data and hydration insights.

How do I return the device?

We provide FREE UK tracked returns. Just follow the instructions provided with your order to send the device back to us.

Can I extend my rental period?

No, the rental is fixed at 2 weeks. If you’d like more time with the device, you’ll need to purchase it or wait until your original rental period ends before renting again.

Does it work for indoor or outdoor training?

FLOWBIO works for both indoor and outdoor sessions, including treadmill runs, turbo rides, Zwift sessions and more.

What happens if I damage or lose the sensor?

If the sensor is damaged or not returned, we will charge the remaining £310 to your card to cover the cost of the device.

Can I rent FLOWBIO again in the future?

Yes! Once your initial rental period has concluded and the device is returned, you’re welcome to rent it again.

FLOWBIO Sweat Sensor – Rental Terms & Conditions

  • Rental Duration: The rental period is 2 weeks, beginning from the date the product is delivered to you.
  • Rental Fee: The cost of the 2-week rental is £69, payable at checkout.
  • Return Deadline: You must return the FLOWBIO unit so that it is received back at XMiles by the return deadline (2 weeks from delivery).
  • Return Process: Use our FREE UK tracked returns service, available at xmiles.co.uk/pages/uk-returns. Return instructions are included with your order.
  • Failure to Return: If the device is not received by the return deadline, we will assume you wish to keep the unit and automatically charge the remaining balance of £310 to the same card used at checkout.
  • Keeping the Device: If you wish to keep the device, email team@xmiles.co.uk with your Order Number, and we will manually process the £310 balance on your original payment method.
  • Damage or Loss: If the sensor is damaged, lost, or not returned, you will be charged the full £310 balance.
  • No Extensions: The rental period cannot be extended. If you wish to rent again, you may do so once the original rental is completed and returned.
  • Support: For help during your rental, contact support@xmiles.co.uk.