Mio Slice review

Compatibility and app

• App graphs out daily PAI earnings
• Doesn't coach you to do more
• Compatible with most iOS and Android devices

The Mio Slice might be like a dozen other fitness trackers when it comes to looks and its modest array of integrated sensors, but it's the custom companion app that can really make or break a device. Unfortunately, the Slice does little to push itself to the top of the pile here.

Open the app and you’re greeted with a circular chart pulling out your weekly PAI efforts on individual days. This looks great and is a brilliant way to see how active you’ve been, and, more importantly, how much effort you’ve put in.

Tap on any of these days and you’ll be offered a more detailed breakdown of your activity, including distances covered, steps taken and active calories burned. With the Slice also capable of keeping tabs on your sleep cycles, it will also show how much you’ve snoozed over the past 24 hours.

The main information here, however, is your heart rate chart. Showing how you earned your PAI points, it breaks down in intricate detail your heart rate at any point throughout the day, including the exact BPM and the activity range you were working in.

While it’s good to see how your body has reacted to certain exercise, that’s about it. The Mio PAI app looks good, but scratch beneath the surface, and things quickly fall short.

Instead of guidance on how to push forward with your fitness goals or increase your daily PAI score, you’re left on your own. There are no coaching elements here, no achievements or target points, and that’s disappointing.

A gadget that’s so geared to the more enthusiastic fitness fan needs to back up the data it captures with tangible benefits on the coaching and progression front. 

As it is, the Slice gets you excited to push your exercise efforts, only to leave you feeling hollow come the end.

It is widely supported though. Whether you’ve got an iPhone or Android handset, chances are the Slice will play nice with your smartphone, as it’s compatible with devices running iOS 9.0 and above and Android 5.0 and up.

Battery life

• Up to five days of life on a single charge
• Requires proprietary charging dock

Its app might disappoint, but the Mio Slice’s battery life doesn’t. Although Mio’s claims of a five-day battery life are slightly ambitious, we managed to get into a fourth day of use, with solid exercise sessions each day.

This staying power is aided by the lack of integrated GPS, but eaten into by the Slice’s heavy use of the optical heart rate sensor.

It’s par for the course when lined up next to the competition, matching the Fitbit Charge 2 when it comes to longevity, with the need for a couple of trips to the mains per week.

When it does come time for a power up, like so many wearable gadgets, the Slice requires a proprietary charger to give it a new lease of life. 

Its addition is somewhere in the middle of the convenient/awkward scale, requiring the wearable to be clipped in the correct way around and then placed somewhere spacious.

Annoyingly, although the Slice will alert you when you’re running low on juice, it won’t actually keep you informed on your remaining power until you’re into the red. At least not on the device. For that you’ll need to break your smartphone out and sync things up, a process that’s hardly ideal.