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ONRHYTHM 500 runner's heart rate monitor watch

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Sale price: QAR 219,00 QAR 219,00

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We designed this watch for runners looking to measure their heart rate to manage efforts when training.

Make easy progress with the interval training mode and the exercise intensity indicator with textile belt.

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Sale price: QAR 219,00 QAR 219,00

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Product Features

A photo of the ONRHYTHM 500 runner's heart rate monitor watch in use

Parameter measurement

Stopwatch, Heart rate (BPM and %HRmax), calories


Target zone (BPM or %HRmax) - Intensity indicator - Interval training - Lap time

Ease of use

Bluetooth coded transmission: optimal connection with the watch


Watch: 5 ATM (swimming) - Chest strap: 1ATM (water splashes)

User comfort

Textile HRM chest strap for enhanced user comfort.

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Product Reviews

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1465 reviews

ONRHYTHM 500 runner's heart rate monitor watch
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Did not work

Did not work, failed to connect to the monitoring band. Trying to get customer services to sort it out or refund.

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Heart and Watch Review

This is a versatile product, not only does it connect to the watch but at a fraction of the cost of a Polar heart rate monitor it also connects to the Polar V650 and a Peleton spin bike! A chance and most excellent purchase.

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Doesn't perform

The connection between Chest Strap & Watch kept having to be re made. However even if that hadn't happened it wasn't a good purchase. You could not exercise with a constant BPM display on the watch and had to use the buttons every time you wanted to check your BPM. Technical Support tried several ways to resolve but despite efforts couldn't be dine. Item was returned for a refund with no quibble.

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Hello David,

Thank you for taking the time to give this feedback and I'm happy to see that although the watch was not suitable you were able to receive a full refund.

From now on, all of our newer heart rate products will use an optical sensor rather than a belt, eradicating any connection issues. In terms of the constant HR display, once you have selected "activity" and pressed start, the HR should then always be displayed on your screen.


Problem reading display

Anyone who needs glasses and runs without them will have a problem reading the bpm - too small

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Hello Chris,

Thank you for taking you time to give us this feedback. The design team have noted that this has been an issue for some of our customers. As a result this product has just recently been replaced by the HR500 that comes with larger numbers. However one of the changes is that this product measures heart rate from the wrist rather than using a chest strap.

If you contact your local store they may offer an exchange or refund.



Disappointing. I've used several other Decathlon/Onrhythm heart rate monitors before over several years but they don't last especially long as the strap tends to become crack and break with time. This one is supposed to have a lap time function but it doesn't exist (I've looked at a number of them in different decathlon branches just to check). The previous, discontinued Onrhythm 430 was good to use (until the strap broke).

Hello Richard,

Thank you for taking your time to write a review on this watch. I'm sorry to hear that it hasn't been satisfactory. The lap time should work on pressing the bottom left button during the activity. This product comes with a 2 year warranty, so if the strap or lap button is broken then please take it to your nearest Decathlon branch so that my colleagues can offer a solution.


Heart rate watch

Easy to set up works well and looks great nice quality

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lap times

This watch/HRM is supposed to record lap times when the bottom left button is pressed. However all mine does is change the display of information on the screen. I have wrote to the support centre and have received no reply. This is now the second HRM that I hav bought from decathlon. The first was the chest strap which was advertised as being compatible with Runkeeper which was not the case. Getting fed up of reading specs that don't apply to the products you sell

HRM for old eyes

My old non-Bluetooth HRM failed so I was looking around for an inexpensive replacement. I was hoping that this Bluetooth device would register on the Concept II rower PM5, but it doesn't. I find the digits on the wrist watch too small and low contrast to read whilst exercising without my glasses. However, I have found that Polar Beat, downloaded (for free) to my Android phone, recognizes the chest belt and displays my heart rate sufficiently clearly that I can see it! And it draws a little graph! Just as an aside, the Matrix machines in the gym I go to only communicate with this chest belt intermittently. This because the chest belt is Bluetooth Low Energy (BLE) and the Matrix electronics is standard (old) Bluetooth.

Good Value

Inexpensive HRM, I didn't buy this with the intention of connecting it to my phone as I actually move around quite a lot during workouts and would destroy any delicate electronic device. The chest band has stayed in place for every workout so far, circuits, aerobic style classes, plyo activities, treadmill and weights - with one exception; the band slid down and lost connection using TRX straps, whilst doing suspended press-ups and reverse flys. The watch doesn't seem to warn you when outside the target HR range, but at least I've figured out why I feel faint during HIIT sessions.

ease of setting up hrm

it is a real challenge setting up this HRM! you really have to be tech savvy and that i am not I go forward bravely Jude

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Bluetooth connectivity

The bluetooth spec mentioned it is compatible with all common activity apps. When trying to pair it doesn't work and request a pairing code. After some research on the geonaute website it appears it can only be paired to a endomono and runtastic pro. I would not recommend this heart rate monitor

Hi Dries,
Thanks for your feedback on this HRM. It helps our engineers to keep working and improving on the connectivity of our Electronic range.
Federico, Running Leader

great piece of kit, works all the time, no issues

Difficult to connect!

It always took me sooooo long to connect! Once it is connected, it will hang after around ten mints and connect again! So difficult to use!


I'm sorry to hear that you have had issues connecting to your Onrhythm500 HRM.

There are two points you can check:

Do you moisten the sensors on your belt?
Is the batter well charged?

If you are able to return to store we can offer check with a replacement battery for you or offer an exchange or refund. 

Kind regards, 

David Daker
Market Manager Nutrition,
Electronics and Accessories,
Good value for money, but...

I bought this product aware of its limitations, so no complaints about the functionality. The heart rate belt can even be connected to a smart phone (of course, losing the ability to connect to the watch.) I would rate it 5 stars, but... The right lower button became wobbly and started making an alarming clicking sound indicating it may fall out of the watch. And that just after few usages, once in the pool with my kids and a couple of times on a bicycle. Will see how durable it is.

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Hello there

Thank you for your feedback :)

Australia is a retailer that sells its own 'Passion Brands' - these are brands that are developed in-house. (We conceive, develop, manufacture & retail). This allows us to provide the highest quality possible for our customers and our trademark low and prices.

Your opinion is important to us as we continuously strive for our customers` full satisfaction and please give us an update on how the watch is going!

We will be very happy to have you back shopping with us.

Looking forward to hearing from you

Daniel Khoury

Fitness / Footwear Commercial Director & Buyer

Nothing fancy but works very well

Need an inexpensive H/R chest watch for rowing. Works really well and is very simple to use. H/R, stopwatch and basic zone information. Excellent product for the money.

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Additional Product informations



  • 90% Polyurethane
  • 10% Stainless Steel


  • 70% Polycarbonate-Acrylonitrile Butadiene Styrene
  • 30% Stainless Steel

Inside room

  • 100% Printed Circuit Board


  • 100% Polymethyl Methacrylate

Why run with a heart rate watch?

Heart rate is measured in BPM (beats per minute). The more intensively you exercise, the faster your heart beats, and the more your BPM increases. As you train, you will learn the best heart rate for you to be able to complete your run without losing your breath. Aim for that rate, and you will be able to run more regularly and more easily.

Fabric strap for greater comfort

Electrodes have been built into the elastic of the fabric strap. The electronic module is attached on the outside of the elastic. As a result, no hard components are in contact with your skin.It is also possible to remove the module to put the strap in the washing machine. Note: the module is perspiration and rain resistant, but must not be put in the washing machine.

Measure the intensity of your exercise

Unless you set the manual target zone, the watch automatically indicates the intensity of your effort in real time using your heart rate: very light, light, moderate, hard or very hard workout.Very light: 50 to 60% of your MHRLight: 60 to 70% of your MHRModerate: 70 to 80% of your MHRHard: 80 to 90% of your MHRVery hard: 90 to 100% of your MHR

Running with your heart rate to set the pace

Are you often out of breath at the end of a run? The HR gives you real-time information so that you can adjust your speed and avoid going beyond your limits. When the watch indicates "Weak" intensity, you can run and talk at the same time. In the "Moderate" zone, exercise is more intense, but you shouldn't lose your breath. In the "Difficult" zone, you should be out of breath within a few minutes.

Running with your heart rate to burn fat

Do you run to stay in shape? The "Weak" zone is particularly useful because it allows you to burn more fat and avoid losing your breath. In fact, in this zone, your body is not under stress. It has time to burn fat properly to turn it into energy for your muscles.

Set your target zone

You can set up target zones for better management of your training. A graphic indicator shows you, in real time, whether you are within the target zone you have set up.The watch allows you to set heart rate target zones (in BPM or %HRmax).

Program your interval exercises

With this function, you can set up a full interval training: warmup time, active time, rest time and relax time, number of interval series and rest time between series.

Compare your runs

The watch gives you a summary of your last 5 runs. For each session, you'll find your run duration, your average heart rate and the number of calories burnt.If you have set a target zone, you can also see the time spent in that zone.

It's a watch too!

The watch also tells the time and date, for everyday use. You can also set an alarm.

Easy to read in the sun and in the dark.

The watch has what is known as a reflective screen. It reflects the surrounding light.The more sun there is, the easier it is to read the screen!When running in the dark, you can use the backlight button to light your screen.

Can i connect my watch or my strap to my phone?

We chose to use our Bluetooth strap to ensure the best possible connection between the watch and the strap. In real terms, it is therefore possible to contact the strap to any sports application on the market which has a heart rate function. But please note: the strap can only be connected to one device at a time. If it is already connected to a phone, it cannot be connected to a watch.

Can my signal be disturbed by other heart rate monitors?

No! The signal of the watch is encrypted. The communication between your watch and your strap is therefore unique, and will not interfered by another heart rate monitor. That said, while your watch is pairing with the strap, it is important to stay away from other heart rate monitor users. Once they are paired, you can use your watch near other users.

How is my heart rate measured?

Your heart rate is measured by the strap worn around your chest.The strap has two electrodes and a transmitter.When your heart beats, it transmits very weak electric fields. They are detected by the electrodes and sent to your watch via the transmitter on the chest strap.


Watch: CR2032 included - Belt: CR2032 included

User restrictions

This watch is designed for sport and leisure. It's not a medical device. The information provided by the watch is for information purposes only and must not be used to track a pathology.

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