Big test: Four fitness trackers go head-to-head on sleep tracking

The biggest sleep trackers duke it out
Big test: Fitness trackers for sleep

The more we learn about sleep, the more we understand about just how crucial regular, quality rest is for our health. That's why most fitness trackers and smartwatches have the ability to track our rest in some capacity, though it can often feel like a taped-on afterthought.

So we've put a handful of fitness trackers head-to-head to see how they compare when it comes to sleep. We're only looking at fitness trackers here, not smartwatches like the Samsung Gear Sport or Apple Watch. While some smartwatches do offer this feature, poor battery life tends to impede their ability as effective sleep trackers.

Big test: Fitness trackers for cycling compared

We're not just looking at accuracy here, but what the apps then do with these numbers; how they incorporate this data into the wider picture of health and actually help us improve our sleep. We want to know who's actually telling you something, and who's just chucking numbers at you?

Also worth noting that, while we used specific devices from each manufacturer, the tech is often the same across their wearables. So for example, we used the Garmin Vivosport, but you're going to get pretty much the same deal if you're wearing the Garmin Vivomove HR. Same goes with using the Fitbit Ionic instead of the Alta HR; other than how comfortable they are to wear in bed, the sleep tracking experience is going to be the same.

Garmin Vivosport – 4th place

Big test: Four fitness trackers go head-to-head on sleep tracking

Garmin is ahead of the competition when it comes to running and sports tracking, but sleep still feels like an afterthought, and while it might have made our favourite sports watch of 2017, it comes in at fourth place when it comes to sleep tracking.

Wareable verdict: Garmin Vivosport review

We tested the Vivosport for this article, but you'll find Garmin's sleep tracking on most of its devices. In terms of accuracy, Garmin's is inconsistent. Sometimes it can be wildly off; other times it's got my sleep and wake-up times spot-on.

In fact, on one night where I woke up a couple of hours before my alarm and took a while to drift off again, the Vivosport detected this extra chunk of sleep while the others didn't. Garmin tracks light sleep, deep sleep and wake time, which is all inferred from movement. It will check your heart rate through the night to find that lowest resting rate, but it doesn't use this to separate out sleep stages. More frustratingly, there have been several occasions where it's tracked my sleep when I'm not even wearing it.

Big test: Four fitness trackers go head-to-head on sleep tracking

But it's in the post-sleep analysis that Garmin most notably lags the competition: there really isn't anything here beyond the basic graph. Yes, you can see how your sleep matches up to your target, but there's no other feedback.

There's a lot of missed potential here. Garmin's recovery guidance is helpful for runners to ensure they're getting enough rest before the next workout, and with sleep being so important to recovery, it feels like it could incorporate sleep data into the overall fitness picture. Garmin's also broadening out its wellness package with things like HRV for stress, so its lacklustre sleep tracking stands out all the more. Needs work.

Accuracy: 2/5

Comfort: 4/5

Insights: 2/5

$199.99, garmin.com | Amazon

Withings/Nokia Steel HR – Bronze medal

Big test: Four fitness trackers go head-to-head on sleep tracking

The Withings Steel HR – soon to be rebadged as the Nokia Steel HR – is a superb all-rounder bolstered by the excellent Health Mate platform. The Withings Steel HR is a fitness tracker-smartwatch hybrid, and its impressively slender design makes it more comfortable to wear in bed than even some of the purely dedicated fitness trackers.

Wareable verdict: Nokia Steel HR review

Like every other device on our list, sleep tracking is automatic. Accuracy isn't perfect, but it's performed well at getting my wake-up times, and results were generally better than Garmin's.

At the end of the night all that data is poured into the Health Mate app, where you'll be able to see a breakdown of your sleep. Like Garmin, this is divided into deep sleep, light sleep and awake time, and like Garmin you'll also see how close you got to your set goal (eight hours, in our case). The Steel HR only uses movement data – hence why you can't get REM information – but you can also get the Withings Aura, which tracks respiratory and heart rate data too, to get REM sleep data.

Big test: Four fitness trackers go head-to-head on sleep tracking

Where Withings outdoes Garmin is in how it does a little more to encourage you to improve those numbers. There are a handful of growing wellness programs in the Health Mate app to help you improve yourself, and Sleep Smarter is an eight-week program focused on how your weekday and weekend sleep patterns diverge. Once you've activated it and used it enough, the app will start scoring you to tell you how similar your weekday and weekend sleep patterns are, and the effect it's having on your health. There are more programs on the way too.

Otherwise it's still quite a simple affair, but with Nokia's focus on delivering a more comprehensive picture of our days' health, we'd like to see it do more when it comes to sleep.

Accuracy: 3/5

Guidance: 3/5

Insights: 4/5

$179.95, health.nokia.com | Amazon

Polar A370 – Silver medal

Big test: Four fitness trackers go head-to-head on sleep tracking

Polar squeezes ahead of Withings/Nokia in our rankings by just a small lead. Earlier this year Polar introduced Sleep Plus, a new sleep tracking platform that works on the A370 fitness tracker and M430 GPS running watch. Neither of those are very comfortable to wear in bed; the A370 is chunky and the M430 is even bigger.

Wareable verdict: Polar A370 review

Tracking is based, again, just on your wrist movements, so it doesn't take advantage of the heart rate sensor in the way Fitbit does. Accuracy has been very good in testing, but Polar has a couple of other features to give that post-night analysis a bit more meaning.


First, it gives you feedback at the end of each night, taking into account your own self-assessment of whether you're feeling groggy or spritely come the alarm clock. Subjective feelings are important – different people require different levels of sleep to feel rested – and being able to tell the app how you feel each morning helps it assess how well you're doing.

You also get something called sleep continuity, which scores you better the fewer interruptions you have through the night. By logging onto the desktop version of Polar Flow you'll get a better view of how your sleep has changed over time, too.

Big test: Four fitness trackers go head-to-head on sleep tracking

The insights Polar offers don't run as deep as I'd like, but you get a small paragraph that sums up your night and tells you things like, "You didn't sleep as long as you planned to, and the quality of your sleep was rather poor. But it looks like you're still feeling refreshed, so no need to worry."

It's a little undernourished, and I'd like to see Polar step up these insights to be a bit more useful, other than telling me a lot to think if "anything comes to mind" that might have interfered with my sleep. But I've found the accuracy to be good, and I like how Polar is taking a stab at longer term assessment.

Accuracy: 4/5

Guidance: 3/5

Insights: 3/5

$179.95, polar.com | Amazon

Fitbit Alta HR – Gold medal

Big test: Four fitness trackers go head-to-head on sleep tracking

If you've been following the narrative of sleep tracking this year, it should be no surprise that Fitbit has come out the winner of this test. Earlier this year Fitbit gave its sleep tracking a total overhaul; where it had previously offered a nightly overview similar to what we've seen above, it now dived deeper with Sleep Stages, more closely intertwining heart rate and accelerometer data to track whether users are in light, deep or REM sleep. It also introduced Sleep Insights, offering feedback that gets more useful and personal the more sleep you track.

Wareable verdict: Fitbit Alta HR review

As far as accuracy goes, Fitbit leads the way. It's not totally foolproof, and there have been times it's got my wake-up time slightly wrong, but Sleep Stages has greatly improved tracking on Fitbit's devices. Right now these advances sleep features are available on the Alta HR, Ionic, Charge 2 and Blaze. If sleep tracking is much more of a priority for you than workouts, then as the smallest of the family the Alta HR is easily the most comfortable tracker to wear to bed.

Big test: Four fitness trackers go head-to-head on sleep tracking

While the insights can sometimes feel generic, long-term use brings more useful advice, which includes taking into account how your activity and sleep patterns are related. For example, if you're sleeping better on days when you go for a run, it will start telling you that. I'd like to see these insights get better still, but when put up against the others in this list the Fitbit Alta HR was the obvious winner in accuracy and feedback. This is the one to beat.

Accuracy: 5/5

Comfort: 4/5

Insights: 4/5

$149.95, fitbit.com | Amazon


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