Fitness bands seem ten-a-penny these days, but the Sony SmartBand 2 is one of the few wearables under £100 that comes with a built-in heart rate monitor - making it an enticing prospect for those who don't want to splash out on the latest FitBit or Jawbone.
What's more, Sony claims it can also measure your stress and recovery levels by tracking your heart rate variability (the time difference between two consecutive heart beats), adding an extra layer of data to the mix alongside its continuous pulse tracking, step counting, calorie counting and sleep monitoring.
It's a well-rounded fitness band, although the lack of physical display will no doubt be a bit of a deal breaker for some. Instead, Sony leaves all the data analysis to its SmartBand 2 and Sony Life Log apps on Android (4.4 and above), or the Smart Band 2 and Apple Health apps on iOS (8.2 and above).
That's not too much of a problem, though, as the band itself is pleasingly minimal. Made out of soft, silicon rubber, the SmartBand 2 is very comfortable to wear and its meagre 25g weight means you can more or less forget about it entirely. This is crucial if you're going to wear it at night, as the last thing you want when you're trying to get to sleep is to be reminded that you've got something strapped round your arm.
With IP68 ingress protection as well, you can easily wear it in the shower, while you're running in the rain, or even in the pool up to 3m for 30 minutes as long as you rinse it off in fresh water afterwards. The metal clasp is also very easy to fasten, but the latch sometimes doesn't lift up correctly when you want to take it off, so you'll occasionally need to get your fingernails in there to make sure the strap doesn't get caught.
However, the band is merely an empty shell, as all the main tracking hardware is housed inside a tiny removable module which you can easily pop in and out when you need to charge it. With a battery life of around two days with the heart tracker enabled (or five if you switch it off and put it in Stamina mode), the SmartBand 2 isn't quite as enduring as other fitness trackers, but it's extremely quick to charge over micro USB, taking around 30-60 minutes to get back up to 100%.
The only type of control on the SmartBand 2 is its single button on the side, which turns it on or off, and snoozes alarms. There are also three multi-coloured LEDs which indicate charge and can change colour to alert you to different types of notification from your phone.
The smart alarm is an excellent feature, as it uses the SmartBand 2's accelerometer to detect and when you're in light sleep as opposed to deep sleep, waking you gently with a continuous series of pulse vibrations to help you feel less groggy when you get up. It works extremely well, and it certainly beats having to wake up to a blaring alarm clock every morning.
However, one of the SmartBand 2's biggest weaknesses is that its automatic activity tracking isn't as accurate as it could be. While it's great that you don't have to set each activity manually, it can often get quite confused about what you're doing, as there were numerous occasions when it logged me as sleeping when I was actually watching a film in the cinema, cycling when I've been driving, or running when I've simply been walking quite briskly to catch a train.
On the whole, though, its step measurements seemed relatively precise while I was wearing the band, but its calorie counting was very, very generous indeed. This is a shame, as other fitness trackers I've been wearing at the same time have consistently measured around half the number of calories I've burned through exercise compared to the number calculated by the SmartBand 2.
It's a bit of a pain that you have to use two apps to get the most out of your stats as well. While the SmartBand 2 app shows you your daily stats and lets you activate your smart alarm and notification settings, you'll need to use Sony's Life Log app on Android or Apple Health on iOS to put it in any kind of meaningful context.
^ Sony's SmartBand 2 app is great for setting up the device, but you'll need to open Life Log to view your stats in full
For instance, I tested the SmartBand 2 on Android, and while it's great to be able to see at a glance how long you slept for and how many steps you've taken in the basic SmartBand 2 app, you'll need to open Life Log to see how that's changed over the course of the day. It's a pity it isn't all plumbed in to Life Log, as the SmartBand 2 app seems pretty superfluous by comparison.
Still, the Life Log app is pretty comprehensive, and compiles your data into helpful, colourful graphs which you can view by day, week, month or year. It's a shame you can't interact with the graphs in any way, but at least they're easy to read and provide a good starting point for comparing historic data. The Life Log app also gives you 'insights' into your data, such as comparing the number of steps you take each week, how much you've recovered during sleep, and how your data compares to other Life Log users. The advice is quite simplistic, but the step summary can be quite useful to see how you're progressing each week.
^ Life Log produces handy graphs to help you interpret your data, but it also logs everything else you do with your phone, such as the time spent browsing the web, taking photos and playing games
The Sony SmartBand 2 is by no means perfect, then, but it's still a pretty decent fitness tracker for under £100. The heart rate monitor sets it apart from other cut-price trackers, it's extremely comfy to wear, and its smart alarm feature is excellent. It's not quite as precise as I'd like it to be, but it's a good alternative to more expensive heart rate fitness bands, such as the £120 FitBit Charge HR and Jawbone UP3.
Pedometer: Yes, Heart-rate monitor: Yes, Display: No, Battery life: 2 days / 5 days in Stamina Mode