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Rated 5 out of 5 stars

Best sweat sensor and best app ever, so easy to use so easy to read the data as a professional athlete I can’t train without my sensor !

Rated 5 out of 5 stars

What an incredible piece of kit! I’ve struggled with cramp for years. Transitioning from bodybuilding to more functional fitness and running, cramp has ruined so many of my events. I could never f... See more

Rated 5 out of 5 stars

Great Device. This is my 4th workout gathering data in my new FlowBio. And the results seems very accurate. With CF the rate at which an Athlete losses sodium and water is 3x or 4X than normal. S... See more

Rated 1 out of 5 stars

Have been using the sensor for 5 rides and its not fit for purpose. If the sensor moves, and it will as you are either running or riding, you lose all the data. When you do get any data takes for ev... See more

Company replied

Company details

  1. Adventure Sports
  2. Fitness and Nutrition Service
  3. Road Cycling
  4. Running Store

Written by the company

FLOWBIO uses the world’s most accurate sweat sensor to measure your fluid and sodium loss in real time, with that data powered by AHi® - Advanced Hydration Intelligence - the technology that combines your sweat profile, effort, and environment to deliver personalised hydration insights, so you know exactly what to drink, when, and why. Most athletes don’t know how much fluid or sodium they lose when they sweat - and that guesswork leads to cramping, disrupted post-race sleep, empty legs, and dehydration hangovers across training, racing, and recovery. Hydration is deeply personal. Yet most hydration plans aren’t. The Hydration Planner creates session-specific strategies that adapt to your workout intensity, duration, and the conditions. You’ll get accurate fluid and sodium recommendations before each session or race. After each session, log what you consumed and select your favourite electrolyte brands including Precision Fuel & Hydration, SiS, Maurten, and others to keep your data accurate and your strategy personalised. The sensor can be worn on your upper arm with the included FLOWBIO strap, or paired with your HR chest strap. With a 100-hour battery life, USB-C charging, and integration with Garmin, Zwift, Wahoo, and Coros, it fits into the way you already train & race. Unlike other sensors, the FLOWBIO system is a one-time purchase, no subscriptions.


Contact info

4.3

Excellent

TrustScore 4.5 out of 5

21 reviews

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Rated 1 out of 5 stars

Not fit for purpose

Have been using the sensor for 5 rides and its not fit for purpose. If the sensor moves, and it will as you are either running or riding, you lose all the data. When you do get any data takes for ever to sync with Garmin

17 February 2026
Unprompted review
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Reply from FLOWBIO

Hi Robert,

Thanks again for the feedback, and I am sorry your experience has felt unreliable.

I have reviewed your account and can see that all of your recorded sessions have been indoor rides, so please make us aware of any runs which you have not received data for, as we cannot see any Garmin run sessions recorded as such. We can see one failed session that is consistent with sensor movement, but the remaining sessions have recorded successfully.

To help us pinpoint what is happening on the sessions where you did not receive data, could you let us know which specific rides or runs are missing data, including the date and roughly how long the session was?

At the moment we cannot see any Garmin runs recorded on your profile. If you have completed runs and did not receive data, please make us aware of those sessions, because they will not appear in our view unless they are recorded as a run, and synced through.

On the Garmin sync point, could you also share roughly how long syncing takes for you, and which Garmin device model you are using? With that detail, we can help you tighten up the setup so the sensor stays in consistent contact and the data pulls through as expected.

I have seen the ticket you raised with us and I will communicate with you via that channel.

Thanks,
Jamie

Rated 4 out of 5 stars

In principle an interesting product

In principle an interesting product, giving a good insight to my sweat rate. But I would like to have more information about the calculation method and the basics behind

19 November 2025
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Reply from FLOWBIO

Hi Bernhard, please feel free to email jamie@flowbio.com - Jamie will be able to share our latest independent validation study conducted by The University of Montpellier. Thanks

Rated 5 out of 5 stars

Cystic Fibrosis

Great Device. This is my 4th workout gathering data in my new FlowBio. And the results seems very accurate. With CF the rate at which an Athlete losses sodium and water is 3x or 4X than normal. So getting the right numbers is a must!! Still have to try it in hot weather (above 27C) but so far the recommendation are accurate. Thanks FlowBio

23 October 2025
Rated 5 out of 5 stars

What an incredible piece of kit

What an incredible piece of kit! I’ve struggled with cramp for years. Transitioning from bodybuilding to more functional fitness and running, cramp has ruined so many of my events. I could never figure out whether I needed more water, sodium, or potassium — or if it was simply because I was too heavy (100kg).

After using the FLOWBIO device for just three runs, it gave me my half marathon prediction for sodium and water. I ran it today with zero cramp and hit a PB of 1:39:30!

I’m genuinely excited to keep using it to stay on top of my recovery and fine-tune my race-day protocols. 100% recommend!

12 October 2025
Unprompted review
Rated 5 out of 5 stars

Great information and engagement

When I placed my order, I contacted the company to learn more about what was possible and how I could benefit from the data. They took the time to explain everything and provide me with the necessary information. They truly helped me make an informed decision and demonstrated that they take their client relationships seriously.

22 September 2025
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Reply from FLOWBIO

Thanks so much for your thoughtful review, Joeri! We’re really glad the team could take the time to walk you through everything. Making sure you feel confident in how to use FLOWBIO to excel your performance is exactly what we’re here for.

Your support means a lot, and we can’t wait to see how you put the data to work in your training.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

NZ just down the road...

Very good customer service for an international company, included free drink bottle a nice touch

28 August 2025
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Reply from FLOWBIO

Thanks so much for your feedback Scott! We’re delighted you had a great experience with our team — and glad the bottle made its way to you in NZ. We really appreciate your support from ‘just down the road’ and can’t wait to keep fuelling your training.

If you need anything, just reach out.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Great data source

Simple to use and very responsive people behind the scenes. I bought my sensor before the android app had been released so had to talk to support who were great. Very useful data generated.

20 August 2025
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Reply from FLOWBIO

Hi Kath — thank you so much for the lovely review! 💙

We’re thrilled you’re finding the data genuinely useful, and huge thanks for sticking with us through the Android app release. It’s great to hear we could jump in and help quickly.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Good comms

Good communication on questions.

26 August 2025
FLOWBIO logo

Reply from FLOWBIO

Peter, thank you for the kind words — we’re glad our team could support you quickly and clearly. Great communication is something we pride ourselves on, so it’s fantastic to know it’s been your experience too.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Best investment for a while!

I tried this sensor, and it was a game-changer for data and performance insight.

After a few weeks of clear insight into fuelling strategies, I was able to rehydrate properly and wake up feeling ready for the next day of training - previously I was waking up feeling unrecovered and ready to cramp.

1 August 2025
Unprompted review
FLOWBIO logo

Reply from FLOWBIO

Jake, this is a powerful piece of feedback — thank you. Knowing the sensor has not only changed how you fuel and hydrate, but also how you feel the next day is exactly why we’re building FLOWBIO. Waking up recovered and ready instead of drained and cramp-prone is a huge shift, and we’re thrilled to hear the data is making that possible for you.

We’re excited to keep pushing hydration intelligence forward and can’t wait to support even more breakthroughs in your training.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Game changer for my training!

I started using the Flowbio device around two months ago to gain some extra data for my training.

I hadn’t realised the magnitude of the amount I was sweating or the amount of sodium lost during my sessions. Previously I was replenishing with 250-500mg sodium post workout, along with 500ml of water however since using Flowbio, I realised that I lose roughly 1500-1800mg sodium & 1L per hour of workouts!

This varies from session to session for me, depending on intensity, environment etc so it is good to have a tangible amount for me to replenish after each workout and it has allowed me to recover much faster and my output has increased significantly over the last 8 weeks and I believe it is down to being adequately hydrated as I haven’t had such high volume and consistent training ever as I have recently.

Great product and would definitely recommend if you are on the fence!

5 August 2025
Unprompted review
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Reply from FLOWBIO

Robbie, this is fantastic to read — thank you for sharing such an in-depth account of your experience. Mad to see how much you had been under-hydrating! Your story captures exactly why we built FLOWBIO: making hydration tangible, personal, and actionable so athletes can train harder, recover faster, and perform at a level they are really capable of.

It’s brilliant to hear how adjusting your sodium and fluid intake has translated into stronger, uninterrupted training. We’re thrilled you’re part of the FLOWBIO community and grateful for your consistent great energy!

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

If you ain’t measuring your guessing

If you ain’t measuring your guessing. FLOWBIO brings age old techniques into a simple easy to use sensor and app.

1 August 2025
Unprompted review
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Reply from FLOWBIO

Chris, we couldn’t agree more —we’re thrilled to hear the Sensor is making hydration tracking simple and actionable for you. Thank you for putting your trust in FLOWBIO — we’re excited to keep pushing the frontiers of endurance with Peak Performance.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

I’ve been using the FLOWBIO Sensor for…

I’ve been using the FLOWBIO Sensor for a month or so now. The data I’ve been able to discover has been incredible. I’ve been able to record, implement and plan around forecasted weather conditions and this has been crucial whilst racing in hot conditions.

The sensor itself has an amazing battery life and is extremely discreet. The app user interface is easy to navigate and simple. I’ve loved this as it makes the analysing easier.

I wanted to also highlight the fantastic customer service. The team at FLOWBIO have been incredible. I had a call and they were beyond helpful. Very understanding team and this makes it that much more a fantastic experience. I can’t wait to discover more with the device and continue to grow my understanding.

Thank you

9 July 2025
Unprompted review
FLOWBIO logo

Reply from FLOWBIO

Sam, we so appreciate you sharing this. We’re truly delighted to hear how the FLOWBIO Sensor is helping you prepare and perform in tough conditions. Knowing you can plan hydration strategies around forecasted weather is exactly the kind of insight we built this technology to deliver.

We’re equally glad you’ve found the Sensor reliable, the app simple to use, and our team supportive :) We’re excited to keep developing new features and can’t wait to see how the Sensor continues to move the dial on your performance and recovery.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

New user of Flowbio have the device for…

New user of Flowbio have the device for about a month now and my experience has been excellent.

1. Had some trouble with Anpost in Ireland being a pain with customs (nothing to do with Flowbio) all documentation was perfect but they decided to send the device back after accepting payment ! I can honestly say Hattie and the team went above and beyond sorting things out for me. No problems getting the device and unbelievable helpful.

2. When a device is expensive you want to know you’ll be taken care of so I always reach out and ask questions especially technical questions. Not only did I get my questions answered they were answered in detail and all the reference material shared. Also like to say the speed of responses and genuine wanting to help is very welcome.

3. I’ve now been using the device for a month for running and cycling (cycling mostly indoors). The insights I get are fantastic especially with the marathon I ran 2 weeks ago. I followed the guidance as best as I could and while I was still sore the following day I actually thought my recovery was much quicker. I’m awful at drinking water etc ..

4. Battery life is perfect, loads of power for a few long runs and basically get nearly two weeks of training.

Final thoughts , excellent service , excellent product and I’m very much looking forward to seeing the new features over the coming weeks / months. I did my research as I always do and I have to say I’m very happy with my decision. I use a garmin watch so having the details on my wrist will be next level once that feature is released, but for now the app is perfect.

Thanks to the Flowbio team, very happy customer.

Alan.

6 June 2025
Unprompted review
FLOWBIO logo

Reply from FLOWBIO

Alan, thank you for such a detailed and thoughtful review — it genuinely means a lot to us. We’re glad we could get everything sorted with customs and that the Sensor has already become a valuable part of your training and racing. It’s fantastic to hear how you’ve used the insights for both running and cycling, and especially that they made a difference in your marathon recovery.

We’re committed to providing not only powerful tech but also the level of support athletes deserve, so your feedback on our responsiveness and detail really motivates us. Exciting times ahead with real-time Garmin integration and new features — we can’t wait to keep building alongside athletes like you.

Wishing you continued success in training and racing — we’re thrilled to have you as part of the FLOWBIO community!

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Great tech and customer service

I was interested in tracking my fluid and sodium losses during ultramarathon training and racing, and I came across the S1 sensor from FLOWBIO. The team was fantastic answering all of my questions and letting me try the device in their office. It’s a fantastic piece of kit that takes the guesswork out of hydration!

10 April 2025
Unprompted review
FLOWBIO logo

Reply from FLOWBIO

Jake, thank you so much for your kind words! We’re thrilled to hear the Sensor is helping you take the guesswork out of hydration, especially in the tough demands of ultramarathon training. It means a lot that you came by the office and gave the tech a try — we’re proud to be building tools that truly support athletes like you. Wishing you the best in your training and racing.

— Stay hydrated, The FLOWBIO Team

Rated 5 out of 5 stars

Great data helped with a strong race finish!

I was excited but nervous to purchase this sensor, asking myself how good could the data actually be? - but it has paid itself back 10x in the data and insights that it has provided. I spent 2 months collecting data from my training ahead of my first 2025 event. What surprised me the most was my sodium loss during endurance training. Using the app's Event Planner tool was super easy and provided recommendations for my 2 day stage race in the Arizona desert (read sunny and hot!). FlowBios analytics provided recommendations for the event which I followed to the letter - and the results were impressive! Not only was the predictive planner recommendations almost spot on to actual sweat data from the event, by using the sodium intake recommendations I was able to finish very strong without bonking, holding threshold pace after an 8 hour endurance day and then crossed the finish line feeling strong (enough to call the kids and the questioned how I was still looking so chipper after an 8 hour race). The biggest surprise and improvement has been how much sodium I lose during extended endurance training and racing - and by following the recommended intakes, I have felt and performed much stronger during race events without the dreaded bonking or death marching the finish. The S1 sensor is super convenient and easy to use - just like any wearable heart rate monitor. Would highly recommend adding to any endurance athletes protocol - you'll likely be surprised how salty you are!

Also - the aftermarket customer support has been fantastic with the FlowBio team responding to questions and having great constructive discussions for future features and feedback from actual users of the technology

9 February 2025
Unprompted review
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Reply from FLOWBIO

Chris, what a review! Thank you for sharing your experience with using your FLOWBIO Sensor. It's really awesome to hear about your performance and wellbeing improvements from actioning the app's personalised recommendations.

We'll get you on a call with our Sports Nutritionist soon to prep you for Cocodona250.

Rated 5 out of 5 stars

Wonderful product and experience

I booked a slot with the Flowbio team at the National Running Show and to be honest, I didn't have much of an expectation of what to expect.

Upon arrival, I met with Hattie, Will, Ines and Jamie, who are all lovely. They set up the sensor and I started exercising on the treadmill for around 30/40. The sensor was attached to my arm and I barely felt it, it sat nicely.

The test results were incredible and I learnt that day that I have been neglecting my hydration and which is having a huge impact on performance and recovery. I now have a hydration plan for each run I do, and it's so simple now I know what I am doing.

I am using the device to help me to keep on top of my hydration while training and during ultra marathons. This is crucial for my recovery which sometimes is a short turn around between races.

If you are an amateur athlete, professional athlete or enthusiast that either loves fitness tech and/or wants to improve performance (and this includes includes stopping dehydration headaches and pains) and also improve recovery, then this is for you.

3 February 2025
Unprompted review
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Reply from FLOWBIO

Hey Matty, it's seriously wonderful to hear how valuable this data is for your training and bounce-back between races. You're an inspirational athlete and we love working with you!

We can't wait to see how you get on at Chester 50 on the 15th March. Catch you soon!

Rated 5 out of 5 stars

GAME CHANGING DATA

Was lucky enough to meet Stefan, for a podcast episode, after talking and finding out more about the brand and the S1, o had to get my hands on it!

Moving forward, and having a chat with Stefan at Rouleur, I collected my s1, great bit of kit, easy to use and you forgot it’s even on the chest strap most the time.

I made a YouTube video ( kingaidancyclist youtube ) on the thoughts and I was hugely surprised to find my hydration was off during training and found that my body required more/leas sodium depending on the intensity of the session and if indoors or outdoors. The difference was surprising. A real in-sight into what I have to do to perform better on and off the bike.

14 January 2025
Unprompted review
FLOWBIO logo

Reply from FLOWBIO

Aidan hello! Love to hear that you're finding the device easy to use with clear actionable results.

See you in Exeter very soon for that bike ride :)

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