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MyZone MZ-3 review – expert heart rate tracking

Myzone MZ-3 heart rate monitor app and strap
Our Rating :
Price when reviewed : £130

It doesn't count your steps or track your sleep, but MyZone's MZ-3 is a great heart rate tracker that's accurate and fun to use


Pedometer: No, Heart-rate monitor: Yes (chest strap), Display: No, Battery life: 7 months

You might not have heard of MyZone before, but this US-based company has just started selling its heart rate tracking fitness belts in the UK. Its latest device is the MZ-3, which is a heart rate sensor that snaps into a chest strap. This isn’t just any old chest strap, though, as it also has built-in heart rate monitoring electrodes, which, when combined with its custom Bluetooth and ultra-low power wireless sensor module, is meant to provide more accurate measurements of your workout than your typical wrist-based fitness tracker or smartwatch. 

The idea behind the MZ-3 is simple. You exercise with the chest strap – be it running, rowing, cycling or whatever gets your heart racing – and earn points based on your bpm measurement. These can then be used to improve your rank within the MyZone app, compete with your friends and family and unlock badges for sharing on social media.

In this sense, the MZ-3 is rather limited, as all it does is measure your heart rate. As a result, you’ll need to look elsewhere if you want something that can also track your steps and sleep patterns. Still, MyZone claims that the chest strap is 99.4% accurate, which is much higher than your average smartwatch or fitness wrist band. Of course, it’s difficult to put that exact figure to the test, but over the course of my testing, it certainly seemed more on the money than other fitness trackers I’ve used in the past. 

It’s also the first heart rate monitor I’ve come across that pairs with just about any piece of third party equipment. You’ll need to make sure you snap its Bluetooth receiver on to the top of the device before it can start communicating with anything, but you can pair it with just about anything, from Android and iOS smartphones, tablets and smartwatches right through to Garmin receivers and treadmills in the gym. It’s an impressively long list, so you’re very likely to own something it’s compatible with. 

Myzone MZ-3 heart rate monitor module

Design and battery life

This is all well and good, but the MZ-3 is let down by its design. The chest strap is comfortable to wear, but the heart rate module is made entirely out of plastic, which feels a little cheap. It’s also quite chunky, so it can stick out against your chest if you’re wearing tight gym clothing. You won’t notice it under a looser t-shirt, but it’s a shame it’s not thinner and made out of something smoother and more durable. 

The one clever thing about it is that the Bluetooth module remains switched off until it senses skin contact. This is to help preserve battery life, which MyZone rates will last for around seven months on a single charge, so you should get plenty of use out of it before charging it up again. Once you’ve put it on, it then beeps to tell you it’s ready to measure your heart rate, and it switch itself off again when you remove it. 

In testing, its battery life was excellent, as the battery depleted by just a few per cent after an hour-long workout. Of course, the battery will drain faster depending on how long and how frequently you use it, but it’s still more convenient than other wrist-based trackers which require charging every couple of days. It’s easy to charge, too, as it uses a standard Micro USB connection and can reach 100% in just a few hours. 

Myzone MZ-3 heart rate monitor app and strap

MyZone app

Since the MZ-3 doesn’t have its own display, you’ll need to use the MyZone app to see your current and historic heart rate data. This is available on both iOS and Android smartphones, but it also works with the Apple Watch and any smartwatch running Android Wear. You don’t need to have your phone with you when you work out either, as the MZ-3 will automatically sync with your device once it’s back in range. 

Once you’ve been using the MZ-3 for a while, it will eventually calibrate itself to your heart rate, allowing it to work out what percentage of effort you’re putting in to each exercise. This means an Olympic athlete can effectively compete against someone that hardly exercises, for instance, and it will compare their effort percentages as opposed to how many calories they have burned or how much their body fat percentage has improved.

Myzone MZ-3 heart rate monitor

It’s a great way to measure how well you’re doing, and the data will also sync across all your various devices, too, making it easy to keep track of your fitness regardless of whether you’re using your phone, tablet or laptop. 

The app also includes a social channel which lets you share your workouts, calorie intakes and effort levels with friends on social networks such as Facebook. It can also pull in data from other devices such as Withings’ Smart Scales and, on the iOS version of the app, information from Apple’s Health app. 

Myzone MZ-3 heart rate monitor


At £130, the MZ-3 can seem a little cheap when you first get it out of the box, but its feature-rich app more than makes up for it. It works incredibly well, and its emphasis on effort rather than mere calorie burn works a treat in helping to motivate you do your best. 

Realistically, you’re not going to be wearing the MZ-3 every hour of the day, so this is definitely a device for those who regularly exercise and work out at the gym rather than for more casual, everyday use. As such, it won’t be for everyone, but there’s no denying it’s a smart bit of kit. It’s easily one of the best heart rate trackers I’ve used, even if it doesn’t have the slickest design.

Add in the fact that some UK gyms have already adopted MyZone’s Effort Points tracking technology as well, such as Surrey Sports Park where you can sync your data in-house and compete against your peers live on screen, and you have even more reason to get on board. MyZone’s said it’s planning to expand into more gyms over the coming months, too, so look out for it at your local gym if you’re decide to give Myzone a go.

Wearing modesChest strap
Heart-rate monitorYes (chest strap)
Smartphone connection
OS supportAndroid, iOS
Battery sizeN/A
Battery life7 months
Buying information
Price including VAT£130
WarrantyOne year RTB