Your Fitbit smartwatch or fitness tracker can do more than just understand your sleep – it can improve it too.
Not only can it help you feel more rested, but your Fitbit will also watch out for signs of sleep disorders, fatigue or even illness while you snooze.
And you don’t need the most expensive devices in Fitbit’s range in order to get the best sleep tracking.
All current Fitbit devices (bar the Fitbit Ace family) will track sleep, sleep stages and heart rate for the most accurate sleep monitoring. But some go that extra mile.
Read on for our complete guide to Fitbit’s sleep tracking.
How does Fitbit track sleep?
When it comes to activity tracking, Fitbit has a whole range of wearables tailored to suit different needs.
If you wear your Fitbit to bed it will track:
- Hours slept
- Sleep schedule
- Wakeful periods
- Sleep stages and time in stages
- Sleep score
- Estimated Oxygen Variation (Fitbit Versa Family, Sense and Charge 3 & 4, Ionic)
What’s more the following data is tracked at night and logged in the Health Metrics dashboard for Premium subscribers.
- Temperature (Fitbit Sense only)
- HRV
- Resting heart rate
- Breathing rate
- Oxygen saturation
What are sleep stages?
Fitbit can not only detect how long you spend asleep, but also the quality of your slumber.
Your device will use the heart rate monitor and motion sensors to detect which of the nourishing stages of sleep you were in: light sleep, REM and deep sleep. These are known as Sleep Stages.
You can see a breakdown of how long you spent on each stage in the sleep section of the Fitbit Dashboard.
And if you’re a Fitbit Premium subscriber, there’s a dedicated screen for sleep stages, which enables you to see how the night mapped out, and check that you cycled between all of the stages.
Understand the Sleep Score
The Fitbit app takes your sleep duration, sleep depth and sleep restoration data and forms a Sleep Score – a single number that's easier to understand.
It's a score out of 100 and assigned ratings such as ‘Excellent’ and ‘Good’. This forms the basis of how Fitbit is making sleep easier to understand. The score is tracked over time, which makes it easier to take positive steps to improve it.
Fitbit users can see how this score is broken down in more detail. It’s made up of sleep duration, how much deep and REM sleep was achieved and how much of the night was spent at low heart rate levels.
Check in with blood oxygen
The Fitbit Versa Family, Fitbit Charge 4, Ionic and Fitbit Sense all have an SpO2 sensor inside, which can read the amount of oxygen in your blood.
There are sleep conditions that affect your breathing, so checking the level of oxygen in your blood at night can be hugely important.
Millions of people don’t know they suffer with sleep breathing problems such as sleep apnea, so the first sign can be in the Estimated Oxygen Variation data.
What’s more, you can install the SpO2 Watch Face on Versa 3 and Fitbit Sense to see last night’s data right on the watch.
Secondly, breathing rate during sleep can be an important insight into your health.
Evidence from Fitbit’s mass COVID-19 study showed evidence of a change in breathing rate before symptoms appeared. Fitbit devices with SpO2 track breathing rate at night, and the data is collected in the Health Metrics dashboard, which is a Fitbit Premium feature.
Get a better night’s sleep
Guided Sleep Programs are Fitbit Premium’s step-by-step guides to changes you can make towards a better night’s rest. These include a personal bedtime routine checklist, as well as soothing audio tracks for unwinding and helping you to fall asleep.
Going through each sleep program – such as Get More Zzz's – last a few weeks and they’re always on hand to repeat if your sleep habits ever need a tune up.
Finally, look out for Personalized Insights. Everything Fitbit tracks about you, from your activity levels during the day, bedtime routine and resting heart rate, and turns this into tailor-made guidance so you can improve your overall wellbeing.
Get more data with Fitbit Premium
While all of the above is available as standard in the Fitbit app, you can unlock more in-depth features through a Fitbit Premium subscription.
This will appeal to anyone who wants to gain an even greater understanding of their sleep alongside a raft of other extra features including health and fitness guidance and dynamic workouts.
You’ll gain access to a Sleep Score Breakdown, which is a deep dive into your daily Sleep Score showing precisely how it was calculated based on your unique sleep stages and restoration measurement.
This gives you a greater understanding of areas you can look to improve.
You’ll also unlock the ability to view your heart rate throughout the night, which will give you a greater understanding of the restorative effect of your night’s sleep.
How we test
James is the co-founder of Wareable, and he has been a technology journalist for 15 years.
He started his career at Future Publishing, James became the features editor of T3 Magazine and T3.com and was a regular contributor to TechRadar – before leaving Future Publishing to found Wareable in 2014.
James has been at the helm of Wareable since 2014 and has become one of the leading experts in wearable technologies globally. He has reviewed, tested, and covered pretty much every wearable on the market, and is passionate about the evolving industry, and wearables helping people achieve healthier and happier lives.