Sleep Tracking Comparisons – Garmin Fenix 3 and Xiaomi Mi Band


I’m not the greatest of sleepers – sorry, but I can’t be good at everything! So, I’ve always been interested in sleep tracking just how much sleep I do actually get. My Garmin Fenix 3 does this for me thanks to it’s inbuilt sleep tracking abilities (just one more reason why I love it), but it’s difficult to know just how accurate such sleep trackers are. I bought Anna a very inexpensive step and sleep tracker for Christmas as well, called the Xiaomi Mi Band and that too seems to be doing its job well, so it was time for some comparisons.

Sleep trackers generally determine your levels of sleep based on the amount you are moving. Could there be any interference whilst sharing a bed, If I’m fidgeting and not asleep, would that show up on Ann’s sleep stats? How accurate were the two devices when compared? We had however each been wearing our own devices and therefore the sleep tracking stats were different as they were monitoring us individually so it was difficult to get and real answers to these questions. I therefore thought it would be a good idea to wear both devices to see how they compare.

Auto-Sleep and Wake

Both devices automatically detect when you go to sleep and when you wake up. It’s fairly easy to see if they get this right as you generally know what time you went to bed and what time you woke up in the morning and I’m pleased to say that both my very expensive Garmin Fenix 3 and Anna’s very cheap Xiaomi Mi Band are usually very accurate in this respect. In fact my Fenix 3 usually gets the times spot on which is fairly clever in itself.

Sleep Deepness

Both of the devices also measure your levels of sleep during the night. Again this is based on the amount you are moving and they usually show quite different results. According to my Fenix 3, I rarely get much in the way of deep sleep. Last night was a fairly typical night for me, and here’s my sleep stats from Garmin Connect.

Sleep Stats

Sleep Stats

As you can see, I had 6 hours and 13 minutes of sleep in total, but only 15 minutes of that was classed as deep sleep. I wasn’t awake at all during the night though which is unusual for me but correlates with what I thought about last nights sleep as well. As well as this basic overview, Garmin Connect allows you to see your movement levels throughout the night, so here are mine from last night as well.

Movement Levels

Movement Levels

Al’s Sleep

Here are a few more typical nights sleep for me.

As you can see I usually get about 6 hours sleep (these are good nights as some nights it’s much less than that) and only a short amount of that is classed as Deep Sleep. By contrast, Anna’s Xiaomi Mi Band was saying that she was getting much more sleep than me, and that much of it was deep sleep. That would correlate perfectly with what we’d expect. As I said at the beginning of this blog post, I’m just not very good at sleeping. Anna on the other hand excels at it!

Anna’s Sleep

Here are some typical nights sleep from Anna.

As you can see, Anna generally gets around 8 hours sleep per night compared to my 6 hours with somewhere around 2-3 hours of deep sleep whereas I often only get 10-15 minutes deep sleep and anything close to an hour is an exception.

Sleep Tracking Device Comparison

Even though the patterns we were getting were as expected, we still couldn’t be sure if the different sleep patterns we were seeing from our sleep trackers were down to actual differences in our own personal sleeping patterns, or if they were due to recording differences between our devices. I therefore decided to wear both my Garmin Fenix 3 and Anna’s Xiaomi Mi Band at the same time. Here’s the sleep data from both of them on the first night I did so (which actually turned out to be a very good nights sleep for me!)

As you can see, that’s pretty much spot on.

  • Both had me falling asleep at exactly the same time, 10:58pm.
  • Wake time of 5:51am was also spot on between both sleep tracking devices.
  • The Garmin chart shows me waking up a few more times during the night than the Xiaomi Mi Band does, but the one time that I woke according to the Xiaomi seems to correlate exactly with a spell of wakefulness on the Garmin data.
  • Total sleep times of 6:53 and 6:49 were pretty close with the Fenix 3 showing slightly less thanks to detecting a few more waking events during the night.
  • My Fenix 3 showed that I had 42 minutes of deep sleep, the Xiaomi Mi Band had 55 minutes, again fairly close.

Overall, I’m quite impressed with the accuracy of these two sleep trackers and the fact that they both confirm that I do indeed get very little deep sleep. It would be interesting to see how my sleep patterns compare to that of other people so feel free to share your sleep tracking data in the comments.

I do think it shows that I should probably make more of an effort to improve both the time and quality of my sleeping though.

4 Responses

  1. Mum says:

    But would either of you sleep better or worse if alone in the bed.Also was Anna woken by her alarm.
    Interesting though x

  2. Ralf says:

    Thanks for this article!
    Was exactly looking for a comparison like this!
    Great job!

  3. Roy Garreffa says:

    I’ve got the Garmin Vivofit 2 and i’m experiencing the sleep results are not accurate.
    Last night for instance it told me i had sleep before 3am which i’m sure wasn’t the case.
    I want to know how accurate these things are.
    Cheers Roy

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Alan Cole

Alan is a Freelance Website Designer, Sports & Exercise Science Lab Technician and full time Dad & husband with far too many hobbies: Triathlete, Swimming, Cycling, Running, MTBing, Surfing, Windsurfing, SUPing, Gardening, Photography.... The list goes on.

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