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MyZone MZ-Switch review: An optical and ECG heart-rate monitor in one neat device

Our Rating :
Price when reviewed : £140
inc VAT

The only heart-rate monitor with optical and ECG modes, the MZ-Switch is uniquely versatile


  • Accurate in both modes
  • Comfortable to wear
  • MEPs system is simple but fun


  • Problems connecting with Polar wearables
  • Not the prettiest thing

We don’t often dedicate full reviews to mere heart-rate monitors, but with the MyZone MZ-Switch we’re prepared to make a change. That’s because this heart-rate monitor is unique: where most heart-rate devices fall into one of two categories — they usually use either optical PPG or electrical ECG technology — the MyZone Switch combines both in one neat unit.

That makes it the most flexible heart-rate monitor on the market today, but that’s not the only trick in the Switch’s toolkit. It also comes kitted out with its very own motivational system and online community, boosting its appeal over most other mere fitness trackers.

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MyZone Switch review: What do you get for the money?

The MyZone Switch is a multimode heart-rate monitor and, as such, comes with an unusually broad selection of accessories in the box. The majority of your £140 is for the monitor itself: a small, disc-shaped device measuring 32mm in diameter and 10mm thick, which can be attached to a variety of different straps.

A chest belt, nylon wrist strap and a slim, neoprene armband complete the package, along with a stubby USB charging cable and a zip-up, neoprene pouch to store everything in.

When you attach the module to the heart-rate chest belt, the MZ-Switch uses the more accurate ECG (electronic cardiogram) technology to monitor your beats per minute; when you clip it into the wrist or arm strap, it switches to the (slightly) less accurate optical sensor on the rear. In chest belt mode, the monitor turns on as soon as it detects your heart beat; when it’s on your wrist, you press a hidden button on the front to activate it.

There’s also a small LED on the front of the tracker that lights up in different colours to indicate which heart-rate training zone you’re in so you can see at a glance how much effort you’re expending, though this is obviously only useful if you’re wearing it on the wrist or your forearm (if you’re wearing a t-shirt).

Inside, the tracker has built-in storage that’s good for up to 36 hours of workouts, which means you can track workouts independently of your smartphone or sports watch, although it won’t give you pace or positional data, obviously.

A rechargeable battery keeps the tracker going for up to six months of mixed use, and you have the option to connect the sensor to third-party devices, such as sports watches, cycling computers and treadmills via either Bluetooth Low Energy or ANT+. In fact, the Bluetooth connection is dual-channel so, in theory, you could hook it up to three devices at once to record your heart rate.

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MyZone MZ-Switch review: Sensors and accuracy

Whether you use the optical or the electrical sensor is up to you – it’s mostly about personal preference. If you’re uncomfortable wearing a chest belt during certain activities, this gives you the option of wearing the monitor on your wrist or forearm.

You do lose some accuracy if you opt to use the optical sensor over the electrical one. Indeed, MyZone rates the ECG sensor at 99.4% accuracy and the PPG sensor at 95%, and my tests back that up. There’s a touch of lag that afflicts the optical sensor that means chest belt operation is the one to go for if you’re doing short, intensive intervals.

However, I found the optical sensor worked almost as well for me, matching the sensor on the Garmin Enduro’s excellent optical sensor closely, whether worn on the wrist or on the forearm. It was within 3% on heart-rate averages and peaks across all the sessions. Most of my testing was done while running outdoors as I’ve been training for a marathon, but as this was a mix of steady state, high intensity and interval sessions, I’ve been able to give it a thorough workout and it hasn’t, if you’ll forgive the pun, skipped a beat.

While I’ve said it’s up to personal preference how you wear it, MyZone does have its own recommendations (there’s a full list here) and, for many activities, it advises you to wear the Switch as a chest belt. However, for water-based activities, wrist-based is best and there are a number of core activity types where it says you can wear the MZ-Switch anywhere and still get accurate results. Those include hiking, jogging and cycling.

Personally, I stuck with it in chest belt mode while running as I’m comfortable with it in that mode. However, it’s a lot more comfortable wearing the MyZone on your wrist if you plan on wearing it for longer than an hour or two.

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MyZone MZ-Switch review: The MyZone app

The MZ-Switch isn’t only about the hardware, good though that is. You can also use the accompanying app to help motivate yourself to get fitter. Primarily, this is done via the MEP system (MyZone Effort Points), but it’s also possible to book and participate in online classes via the app or choose from a series of structured workouts to add some interest to your gym, home treadmill or exercise bike sessions.

The MEPs system lies at the core of this, however, and it’s a fairly simple concept. Based on your maximum heart rate (this is estimated at first, but updated automatically if you go above your maximum heart rate for 40 seconds or more), MyZone assigns you six heart-rate zones. As you exercise within those zones, you earn points (MEPs) towards a monthly goal. The higher the heart rate, the more points you earn and, when you hit a monthly target of 1,300 MEPs, you have the potential to earn yourself a coveted MyZone status upgrade.

Starting at “no status”, you move to “Iron” if you manage one month at 1,300 MEPs, you go to “Bronze” with three months in a row, “Silver” with six months consecutively and so on up to “Hall of Fame” status with 48 months in a row. Once you get into it, this is quite addictive and a good way to stay motivated on a long-term basis.

One of the best things about the system is that you don’t lose out on MEPs if you use the belt as an external sensor connected to a running watch or other hardware. Simply connect the MZ-Switch with your phone and each session is automatically uploaded to the app from internal storage, regardless of what else you were using it for before.

The app’s ZoneMatch sessions are also a great way to pep up what might otherwise be fairly tedious exercise machine systems, and anyone looking to keep fit at home could do a lot worse than take a look at the Book a Class section, which allows you to participate in virtual video-based fitness classes, free of charge, via the screen of your tablet or smartphone.

In short, the app turns what would otherwise be a fairly mundane, albeit highly competent, heart-rate monitor into a comprehensive tool for improving your all-round activity levels and fitness.

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MyZone MZ-Switch review: Is there anything it could do better?

The first thing to say is that, largely, I had no issues with the MZ-Switch. It connected just fine with the vast majority of accessories I tried, from bike computers and basic running watches to more advanced wearables, and I found it reliable and accurate, no matter what activity I tracked with it. There were no connectivity dropouts, no dodgy data, no issues at all.

Until, that is, I attempted to hook it up to a Polar Vantage V2 sports watch. At this point, the MZ-Switch paired fine but only intermittently transmitted heart-rate data. I’ve reached out to MyZone about this and will update the review if this changes at any point but otherwise, obviously, it’s useless for Polar users at the current time.

Otherwise, there’s not much else to say. It would be nice if you could upload ZoneMatch workouts to the MZ-Switch itself and have it issue audible cues when moving from one zone to the next, as this would allow you to follow workouts on a run or bike ride without the need to take your phone with you. As this would have a negative impact on battery life, however, I understand why MyZone hasn’t implemented this.

It would also be nice if it looked a little more attractive but, if you’re concerned with that, you can always hide it under a sleeve on your forearm.

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MyZone MZ-Switch review: Should I buy one?

Otherwise, the MyZone MZ-Switch is a great all-rounder. As a heart-rate monitor that can be used in multiple configurations – on the wrist, forearm, chest – the MZ-Switch is pretty much unrivalled. It’s accurate, comfortable, easy to use, can be used as a sensor to upgrade your sports watch (as long as it isn’t a Polar) and works across all exercise types.

Add in a bunch of extra motivational tools, online workouts and structured workouts for gym goers and you have an highly effective, all-round fitness-monitoring tool, unlike anything else on the market. The only caveat is that, compared with other heart-rate trackers, it is on the expensive side.