Wednesday, 30 March 2016

Xiaomi Mi Band 1S

I wasn't a great believer in fitness trackers for athletes, but this little device has changed my mind. For $18 (and a bit of waiting for it to make it from China) you get something that's as good as any of the basic fitness trackers, and even has heart rate monitoring built in.

Activity monitoring

This is the prime function of these devices so it's no surprise it does the job. You can set a target number of steps, and it gives you a pretty clear vibration to let you know when you're done (or you can check the number in the app). There are three lights on the front of the device, and if you swing your arm up just right (there's a knack), they will light up to show you how far you are towards your goal.

I'm not convinced that this part is that useful for athletes, though it can be interesting to see how many steps you're doing on what is supposed to be a rest day, or perhaps when wandering around an expo the day before a race. But most triathletes don't need to be too concerned with keeping their activity levels up!

It does attempt to split out 'activities' during the day (which basically means runs), and certainly going by those the step count seems accurate. However there isn't an obvious way to change the stride length, and with my legs being on the long side I get a fairly consistent 20% underestimate on distance.


I don't really use this myself but you can apparently use the device to notify you of calls/messages etc. There are aftermarket apps which allow you to customise vibration patterns etc to your heart's content, or the official app allows more simple notifications

Sleep monitoring

I was impressed with this. There's no option to tell it when you're going to sleep (like the Garmin 920xt), but its automatic detection is quite impressive. It seems to be able to spot the difference between reading in bed and sleeping. The only time I've had it confused was a 2am trip to settle a crying child - it decided that was my bedtime; it was easy to correct the 'sleep start' time in the morning.

The band makes an effort to give you 'deep sleep' and 'light sleep' stats, and even uses its heart-rate monitor to improve detection. Unfortunately it doesn't record those heart rates for later use.

Heart rate

This device has an optical heart rate monitor built in, primarily I believe for improving sleep detection; however it's quite handy for checking morning resting heart rates. The official app seems to struggle with rates below 57 (not much use for a triathlete) (EDIT: the latest version works fine!), and I was trying the aftermarket app Mi Band Tools. For some reason I can't fathom (LED warm-up?), the first reading it takes each time seems to be a bit random - so although it supports intermittent (eg hourly) readings, they're not much use. However, you can stick it on 'continuous' for a couple of minutes each morning before I get out of bed, and end up with a nice record of resting heart rate. I've since spoken to the developer of MBT who says that the incorrect first reading is a known problem but is not going to be fixed. Other apps (eg Mi Heart Rate) appear to manage better in this regard.

At least in me, heart rate during exercise doesn't seem to be quite so useful. It just about works on the turbo, but not running. But at those times I'm generally using an ANT+ strap anyway.

Physical build

Given that it's about 1/4 the price of even the cheapest FitBit, you'd expect some cheap rubbish. It's actually pretty smart and feels well-made. The device itself is an aluminium lozenge (with Apple-esque micro-perforations to let the LEDs shine through), and slots into a well-made silicone band - or a variety of aftermarket clips and straps. The two-part construction does mean that sweat and shower water can get trapped in between the band and the device, but this hasn't been a major problem. Whilst the device is shower-proof, and my wife has been wearing hers in the shower, I've tended to avoid doing so to avoid water build-up.

Battery life

It needs charging about once a month, even with a fair bit of messing about with the heart rate. Charging is via a small USB clip, and takes about two hours.


I'm impressed. Improvements to the heart rate monitoring would sell it to me entirely - I dream of using Mi Heart Rate or similar apps to measure overnight heart rates accurately. However it's much cheaper than devices which don't even try to measure heart rate, and it makes morning measurement very easy. So definitely recommended.

I bought mine from GearBest

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