How to use Your Apple Watch to Track Sleep

Mar 16, 2023 | fitness, Latest Trends

If good quality sleep is important to you, and you own an Apple Watch, then I’ve got the sleep app for you! I’ve been using it for a few years and it has helped me improve my sleep quality. Let me explain how…


AutoSleep for Apple Watch (sorry not available on other wearables) tracks sleep by using the sensors on an Apple Watch, such as the accelerometer, microphone, heart rate monitor, to detect movement and changes in heart rate, temperature and respiration. When we wear our Apple Watch to bed, the app automatically begins tracking our sleep and uses advanced algorithms to analyze the data collected. The app then provides detailed information about our sleep patterns, including the duration of sleep, the quality of sleep, and the amount of deep and light sleep obtained. By using this data, the app can offer personalised recommendations for improving sleep quality and overall health and wellness.

Tim Robards put me onto this app a few years ago and it continues to win many best app awards. Here’s how I like to use it:

How to Track your sleep

Some people struggle with the best process of wearing their watch to bed, so here’s my top tips for ensuring your watch stays quiet and dark all night. 

Step 1: Download the Autosleep App, easy to set up.

Step 2: Charge your watch in the afternoon/evening: I am now in the habit of charging my watch between 5pm-bedtime. As soon as I get home from work I pop it on the charger in my bedroom.

Step 3: Watch on at bedtime: Set your watch (or phone) to sleep focus, and turn on theatre mode. If you are concerned about EMF you can also put your watch on airplane mode

Step 4: Lights out: Go into Autosleep on watch and tap ‘lights out.’ This is an optional step, you can just fall asleep and it recognises that. However for a more accurate bedtime, I like to tap ‘lights out’

Step 5: Wake up and view your sleep session report: Go into Autosleep on your phone and view all the fascinating sleep session data from last night. No two nights are ever the same!

Interpret your results

Whilst there are so many interesting data points, the below have been the most useful for me, and are most impacted (positively or negatively) by (often controllable) lifestyle factors. 

Total Sleep

This reflects the time that you spent asleep. You fill this ring by sleeping enough hours to meet the sleep hour target that you set in the AutoSleep wizard.  You can see on the ring gaps where I was awake, even for brief moments. 

Quality Sleep 

The Quality ring shows hours of quality sleep achieved. This makes it easier to compare with other days. This looks at the overall sleep time, how much light sleep, how much deep sleep, how restless and the nocturnal dip in heart rate and determines how much quality sleep you had. The ring completion target is 85% of your required sleep hours.

Deep Sleep

The Deep Sleep Ring is the number of hours where you met a sufficient nocturnal dip in heart rate combined with minimal movement. This is also known as slow wave (or Delta wave) sleep and is the most restorative stage and is when our body does the most repair work. During this stage, our brain waves slow down even further, and we enter a deep state of relaxation. Our blood pressure drops, and our breathing becomes slower and more regular. This stage of sleep is essential for physical recovery and is also important for memory consolidation, psychological processing and learning.

The main value of this ring is to compare it against your own historical data rather than to other people. The ring completion target is 35% of your required sleep hours. 

Average heart rate

This is your average heart rate during the time that you were asleep. The ring reflects the quality of the nocturnal dip in heart rate. This is measured as the percentage difference between your average heart rate when not engaged in physical activity and your average heart rate when sleeping. The fitter and healthier you are, the lower your AHR, and the more stressed or unwell you are the higher (hint: watch this number climb on days you consume alcohol!). 

Readiness score

AutoSleep’s readiness rating I find super useful and always consistent with how I feel. If I wake up groggy, my readiness score is always low, if I spring out of bed it’s high. I’m surprised by how accurate this is. To ascertain this score Autosleep considers waking pulse and waking heart rate variability to give insights into your mental & physical state. 

About Waking Pulse

This is your heart rate in beats per minute upon waking. It’s the gold standard way of capturing your resting heart rate as it is done under controlled and consistent conditions. This lets you easily identify trends. When you wear your Watch to bed, AutoSleep does this for you automatically. 

Generally speaking, if your heart rate is higher than your established baseline average then you are likely to be more stressed. If lower, then less stressed. Stress may come in many forms, it may be due to illness, decreased fitness, lack of recovery, mental stress, overtraining or many other factors. 

About Heart Rate Variability (HRV)

It’s a common misconception that a healthy heart always beats like a metronome, every beat in perfect time. In reality, this is what happens when we are more physically or mentally stressed. When we are not physically or mentally stressed, the heart tends to have a more significant beat to beat variation. So a higher HRV is actually a healthy sign. 

How to Record Waking HRV

There’s a surprisingly easy and pleasant way to capture HRV. Upon waking, do a 1 minute session using the Breathe app on your Apple Watch. The best way is to set this up as a complication on your sleeping watch face

Sleep Fuel Rating

Sleep Fuel will look at your average HRV during sleep. This then lets AutoSleep compare your HRV during sleep to a base figure again under controlled conditions. This assists in determining the restorative qualities of your sleep. Keep in mind that sleep fuel is focused on quality, not duration.

Sleep Bank

AutoSleep’s sleep bank uses an algorithm over your last 7 night’s sleep to determine if you are in sleep credit or sleep debt. Sleep debt is the difference between the amount of sleep that you should be getting and the amount that you actually get. If you aim to stay in the “green” (credit) you will generally feel healthier and more alert during the day. I find this super motivating to prioritise an earlier bedtime or weekend sleep ins. 

Experiments to Try

I love the saying ‘where focus goes, energy flows.’ Simply by focussing on your sleep data, you’ll notice you become more aware and motivated to optimise sleep. So now you’re interested, your goal ultimately is:

  • Total sleep between 7-9hr
  • Improve time in deep sleep
  • Lower average heart rate 
  • Increase readiness score

So what are some experiments we can try to impact these? 

Box breathing in bed: After you’ve turned out the lights spend two minutes box breathing before going to sleep. Watch this video to learn how, its so simple! My average heart rate is often 2-6 bpm lower on average on my box breathing nights. 

Exercise: It’s no surprise that exercise improves sleep. Compare your sleep session reports on workout days to non-workout days, this can be super motivating!

Don’t drink: Compare your sleep session, particularly your average heart rate on alcohol free days compared with drinking days. For me it’s quite alarming and has been one of the biggest triggers for me to majorly reduce my alcohol consumption. Sometimes my average heart rate can be as high as 10bpm higher even after only two glasses!

Leave 2hr after eating: Compare your sleep session on the nights you leave two hours between finishing eating and bed. Often your sleep scores will be a lot better with that digestive break. This makes it easier for me to avoid the late night snacking (which I’m prone to!). 

Track over time: The longer you use Autosleep the more accurate and useful the reports become. I can now look back and see trends over time, which helps inform my plans for the next few weeks. 

Ultimately if you are looking for motivation to improve your lifestyle habits, sleep trackers like Autosleep clearly show how your daily habits are impacting your sleep. This is super helpful (and motivating), and as your sleep improves, you feel better, you make healthier choices and the positive cycle continues!  If you do give Autosleep a try I’d love you to report back to me. 


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