Mio Fuse review

Heart rate monitoring meets activity tracking but does the Fuse impress?
Mio Fuse

Mio, the heart rate monitoring specialist, announced the Mio Fuse activity band over in Vegas at CES 2015.

The Mio Fuse is designed for BPM based training and taps into the company's heritage with optical heart rate monitoring; as well as already launching its own devices such as the Link and the Alpha, you'll also find Mio's sensors on board GPS running watches such as the TomTom Runner Cardio and the Adidas miCoach Smart Run.

Read on for our full Mio Fuse verdict…

Mio Fuse: Design and display

It's big. That's the first thing you think when opening up the Fuse box. At 30mm wide it's a fair bit chunkier than the likes of the Fitbit Charge HR or the Garmin Vivosmart, although it does still weigh less than 40g and is plenty comfortable on the wrist.

We say on the wrist – for more accurate heart rate readings during workouts (more on that later) you should actually wear the Fuse slightly higher up your arm than you would a regular wristwatch. This takes some getting used to and the natural contour of your lower arm makes maintaining this position a little tricky.

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The Fuse actually comes in two sizes – the aqua version is for little lady wrists and the red one is for manly men. That's a massive generalisation of course. For reference, we had the aqua one slapped on our wrist for testing and it fitted just fine.

The strap itself is made of soft silicone and there's plenty of holes drilled in, which not only helps to keep your wrist cool, it also gives you plenty of sizing options when it comes to clasping up.

The LED based display is bright, clear and responsive and you'll have no issues browsing through the various info and goal screens on offer. A quick tap on the raised spots either side of the display will bring up the time and further tapping reveals the other metrics available to you.

There are no smartwatch notifications, even basic ones like incoming calls or text alerts, although there have been some whispers coming out of Mio Towers that these functions could arrive with a firmware upgrade in the near future.

Mio Fuse: Fitness tracking

Mio Fuse review

The Mio Fuse is essentially a bpm monitor with a few fitness tracker features thrown in; including step counting, distance measuring and calorie burn guestimating (both resting and active).

You'll notice we didn't mention sleep tracking. Although a future software update is set to add it to the mix, it's missing from the Fuse at present. There's no altimeter either, so no stair counting from the Fuse.

What you will get is fairly consistent step tracking – we found the amounts counted daily to be more on a par with the 'stingy' Withings Activité Pop than the more generous Fitbit brigade.

The distance recording is also pretty good for a device not packing GPS. Our 11km run recorded as 10.77km, which is a pretty impressive algorithm-powered measurement.

Mio Fuse: Heart rate monitoring workouts

Mio Fuse review

Unlike the Basis Peak, Charge HR or Microsoft Band, the heart rate monitoring isn't of the 24/7 variety – it's simply designed to be used during workouts. Starting a workout from the band is simple enough – it's a long press to fire up the optical sensor and then a quick tap to start the timer once your heart rate has been detected. You tap again to pause or finish and you can then edit the workout type in the app.

We know what you're thinking – why not just leave the device in workout mode all the time for continuous bpm recording? Battery life is the answer. We tried this method and the Fuse conked out after about 8 hours.

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One brilliant aspect of the heart rate recording, apart from its accuracy, is by using the magic of ANT+ or Bluetooth Smart connectivity, you can transmit your live bpm reading to either another device, such as a GPS running watch or a bike computer, or a third-party running app. The Mio Fuse plays nicely with a wide range of devices and apps – we had no problems syncing it up with a couple of Garmin running watches, as well as with Runtastic and RunKeeper.

When you're in a workout a flashing coloured light will tell you what zone you are in (you can opt for either a three or five zone training setup) and you'll also get a vibration buzz as you change between these. It's a very effective method of bpm training and we even found it worked quite well in the pool – it's waterproof up to 30m.

Mio Fuse: The app

Mio Fuse review

The app the Fuse syncs up with, Mio Go, isn't the most comprehensive companion we've used; with a title display showing total workout time, distance and calories and daily breakdowns of stats and workout data.

Digging deeper into the workouts that have been recorded and you're presented with an overview, a detailed heart rate graph and various averages and maximums – speed, pace, bpm, zone and so on. It's interesting and easy to use, if somewhat limited.

We also found the pairing aspect of the app to be a little temperamental. Sometimes it had our Fuse listed three times – 'nearby', 'disconnected', and 'waiting' and the only way we could get it to sync was to remove the 'waiting' one and repair the one listed as 'nearby'. A bit annoying and this happened a few times (we were using an iPhone 6 Plus, by the way).

Within the app you can alter the order that metrics are displayed, choose the daily goal target, mix up the LED alert frequencies and tell the Fuse what wrist you're going to be wearing it on.

Mio Fuse: Battery life

Battery life is very impressive on the Mio Fuse – we got over a week's worth of life from ours on one occasion, despite us wearing it along to a couple of 1 hour runs.

We did, as mention, hammer the battery by leaving a workout mode on continuously, but for 'normal' use you can easily expect to get the 6-7 days the Fuse creators promise from it.

However, when it comes to charging – it's pretty awkward. The cable and magnetic clasp is nicely portable, and even tucks in on itself. The trouble is though, it's so small that you can only really charge from a laptop USB port on a flat surface. From the mains, you can't get the band to attach firmly enough as it doesn't reach the floor.

Mio Fuse
By Mio
The Mio Fuse is a decent wearable, with accurate heart rate monitoring, an easy to use app and a comfortable, if somewhat slightly oversized, design. If you look at it as simply a bpm based device with some activity extras thrown in, it does the job, although the omission of basic sleep monitoring, notifications and silent alarms are a bit baffling. At £130 / $149 it’s going head-to-head with the more feature packed, and complete, Fitbit Charge HR though – so it’s quite hard to fully recommend it.

  • Accurate heart rate monitoring
  • Okay to use in the pool
  • Decent battery life
  • Plenty of third party support
  • No sleep monitoring
  • Bulky design
  • No smartphone notifications
  • Pairing is a bit buggy


  • Zed says:

    FUSE is good stuff, if you only want heart rate, time and not much more.

    Pro: comfortable, battery(tested all day workout without any problem), display(LED colors), HR, waterproof, later sync data to phone
    Cons: why can't lock screen when I'am in workout mode?(only possible in normal mode), maybe need more advanced vibrating options(to distinguish HR zones)

  • Kaka says:

    I love my fuse! The fact that it is waterproof and can swim with it + monitor heart rate beats a lot of trackers out there.

    I consider Mio Fuse more as a sport tracker than daily tracker. So it is good for those who do sports!

  • eestein says:

    I think it's awesome! I've had mine for a week now and I knew before hand I was only using it as HR monitor. It does the job really well. Although I do agree, the pairing AND the initial HR rate could be faster. Still, awesome choice. As Kaka said, just having an accurate HR monitor plus being able to swim with it makes it a win over all the other options.

    Thanks Mio! Now go and work on that sluggish initial HR, will ya?

  • Creek says:

    Not a fan of mine.

    The app is quite terrible and aside from sleep tracking there are some other pretty key omissions, such as the ability to configure stride length. There is simply no need for such a key component of accurate distance measurement to be merely estimated when you have already been asked for your height, weight, sex, age and so on. Why not stride length? Huh?

    The step counting is as described in the article: a seemingly random number. It is totally not the amount of steps you take. Like a lot of these wrist based toys, it cannot ever know exactly how many steps you've taken and has to estimate the number. But the estimate is wrong by an hilarious margin. They might as well invent another name for the number. Keebarps. I did 12,429 keebarps today.

    The other number that makes no immediate sense is calories. Since the Fuse does not do continuous heartrate monitoring (a major letdown, particularly as my wife's thinner, lighter, less orthopaedic looking Fitbit does, and lasts several days on one fill-up too) and is completely wrong about steps (sorry, keebarps), how on EARTH can it have the temerity to announce how many calories you've burned? It cannot possibly know! Once again it is a random number. Fwalumarts. I burned 7 fwalumarts today.

    Returned to Amazon. Thank heavens for Amazon.

  • fishter63 says:

    Love my Mio Fuse but the part of the band that fastens it down (the 2 little bumps that yo press down at the end of the band) has broken.....one has fallen.    Can I have it repaired and where?

  • Beastmaster says:

    I really like my Fuse after wearing it for two weeks. I've been experimenting to see what my calorie burn would be if I left it in workout mode for 24 hours. The totals are much higher than I woukd expect. Not certain they are correct. 

    I am 46, 175, 5'8. I'm walking about 3.5 miles a day, in morning and at night. It's saying I ended at 3800 yesterday. Higher than any other monitor. 

    Great, if it is correct!  I have been feeling run down and wanted to make sure I was eating enough calories. Bad, if not correct. Trying to lose weight. 

    Any advice?

  • kellie says:

    Do you know if a new updated mio fuse is due to be released soon? 

  • Cathy says:

    What a waste of money. Since I got my Fuse, I've had nothing but trouble with it. Every time there is s software update, nothing works right. Using it with my phone is always a struggle. It's not intuitive at all. Mio tech support had the nerve to tell me the Fuse was for people who are more tech savvy than me. And the latest problem is, it won't charge. I've had it less than six months! Would love to get my money back. My advice? Stay away.

  • Arronholmes says:

    Very disenchanted with my Fuse. I bought it when they were first released from Amazon 18 moths or so ago and it broke after 4 months, and was a complete pain to get replaced, Mio were very unhelpful. Then had problems with deleting workouts, they kept getting reinstated every time I sync'ed and wouldn't delete. Spoke to Mio they said there would be a software update which did work but the software seems to be quite buggy. Then had problems again with it being unresponsive and that the strap started to split. Again Mio Support unhelpful. In the end it has just packed up. I haven't bothered even speaking to Mio Support and have just bought a Garmin Forerunner 235.

    The problem I have with all of these sites is that you only do reviews on the new equipment which really doesn't help. If there were long term tests such as the ones that Car Magazines perform these types of glitches would get identified and pressure placed on the manufacturers to improve.

  • Sad says:

    Had mine for a couple of months.  I want to like it desperately but it fails badly. It is a very good heart rate monitor but that is it. Un-intuitive. The strap design is poor, (form over function.) The syncing of the MIO app is terrible and won't sync for days at a time, yet Strava will pick up the heart rate no problem but the watch won't lock if not in 'work out mode' via the app. Don't waste your money.

  • orilla says:

    The heart rate sensor part of the Fuse is good, however, that is were it ends.  The software is beyond bad and the product build quality is questionable.  I bought one in January of 2015 before the end of 2015 it had begun to split on the back and the buttons on the front did not response.  I was able to get a replacement under warranty, however, the replacement started doing the same thing a couple of months later.  Which the replacement I only wore it while cycling.  After the second failure I wasn't able to get a warranty replacement since it had been a year since the original purchase.  They offer a 20% discount code to buy a replacement which I declined; I don't trust that the replacement wouldn't have the same problems as the first two.

  • jcnietofebres says:


    as a heart rate monitor, the fuse is amazing. I only use it as a heart rate monitor (when running) and don't care about all other features. Yes, the app it's horrible and truly sucks, BUT, since the fuse it's compatible with all other devices/apps as you'll read below, I simply don't use the mio app at all and instead use it with endomondo (running app). If you're looking for more features than just a heart rate monitor, get something else. However, if you want a heart rate monitor to track your workouts with GREAT accuracy, please get the fuse. Another great thing about the fuse is that is compatible with most - if not all - devices (and apps). This is because it has the 3 technologies (ANT+, bluetooth classic and Bluetooth SMART) used to transmit/receive the data to/from devices. I use it with endomondo, which supports all 3 technologies. I always use ANT+ to connect to endomondo but I tested the other two methods (bluetooth classic and bluetooth SMART) and they worked perfectly as well. I've had my fuse for 2 years and wear it all day everyday (I only take it off to sleep), and as a traffic signal technician that works outside fixing things with my hands I am amazed at how tough this thing is. I've bumped and scratched this thing against a lot of things while working and even sliced the silicone that covers the display. However, my fuse keeps working perfectly. It's really heavy duty. Wow, I wrote a lot, I never do reviews but I just love my fuse, and I thought somebody would like to read a review from a 2 year user.

  • Paul68 says:

    I've tested the HR monitor against hospital equipment several times and hospital nurses assure me it is guite, acceptably close to the measurements given by their hi tech monitors. The sleep monitor is nice but it doesn't tell you the Fuse definition of deep and light sleep. I'm sure it not a clinical definition. However the only problem that has to be fixed is the cursed synchronizing. Even though the display reads 'fuse nearby'  and 'connecting', very often the connection doesn't occur. You have to reboot your iPhone 6 to get the sync working again. What a bloody nuisance! 

  • michigander says:

    I wouldn't recommend this device.  I find that the heart rate monitor is not all that accurate (compared with a Polar heart monitor) and the software is not well designed.  Every time I try to download data from the Fuse to my iPhone, I have to delete the device from Bluetooth and then find it again.  Even then it does not always work.  Also, they claim you should be able to wear it in the pool, but I found it does not keep track of heart rate or any other useful information.  There are better devices out there, now.

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