But what does all the data mean? How much deep sleep do you need? And should your graph really look like that? Relax – we've spoken to a sleep expert and got it all figured out.
How does it work?
Virtually every fitness tracker has the ability to map your shut-eye. They work by continuously monitoring your movements during sleep – known in professional sleep circles as actigraphy – and assessing sleep-wake cycles to see whether you're in deep or light sleep.
This information is then presented to you the next morning; usually as a graph on your smartphone app. Most monitors will give you a calculation estimating how many hours of each type of sleep you've enjoyed and also how often you woke up.
Essential reading: The best sleep monitors and trackers
Alternative trackers such as the SleepRate also use your phone's microphone to record any loud noises during the night to help explain why you woke up while the Beddit Sleep Monitor uses a ballistocardiography (BCG) sensor tucked under the sheets to track sleep quality, duration, heart rate and respiration rate.
While not as accurate as professional sleep monitoring equipment, or lab tests, fitness bands can help paint a clearer picture of your own sleep cycles.
But what is good sleep?
While most of us still think of 'getting a solid nine hours' as having enough sleep, this doesn't take into account the number of times you wake up or how much time is spent in each sleep cycle.
A good night's sleep consists of around five or six sleep cycles. One cycle consists of the following:
Stage 1 – The drowsy, relaxed state between being awake and nodding off.
Stage 2 – A deeper sleep where your body temperature cools a little and you become disengaged from your surroundings.
Stages 3 and 4 – These are 'deep sleep'. It is very hard to wake up from deep sleep because this is when there is the lowest amount of activity in your body. It is also the part of sleep where your body rebuilds itself, restores energy and hormones are released. This is the good stuff!
After deep sleep, we slip back into Stage 2 for a few minutes before entering 'dream sleep' – known as REM (rapid eye movement) sleep. Each cycle lasts around 1.5 hours and we need to experience all four stages in order to wake up rested.
What does a good night's sleep look like?
Sadly there's no such thing as a perfect sleep chart, but if you sleep like a baby and wake up refreshed your chart will almost certainly show a steady wave of peaks and troughs.
According to sleep monitoring app SleepCycle, a good night's sleep will show sleep cycle peaks and troughs lasting for around 90 minutes. Notice that for every cycle the person goes into less deep sleep, this is typical for a normal sleep graph.
And while a few drinks can help you fall asleep faster you can see from this graph you'll probably have a lot less deep sleep, be restless and wake up earlier than usual.
But as Professor Colin Espie, world sleep expert from the University of Oxford and Chief Clinical Officer at Sleepio explains:
"Each fitness monitor varies in the activities it monitors, the methods used to record them and the feedback given on the data collected. You may have to become your own detective to discover how the tracked data correlates with how you feel during the day and any factors that affect your sleep."
How much sleep is healthy?
Espie continued: "The number of hours' sleep you need is as individual as your shoe size. Don't assume you need the often-quoted seven-to-eight hours - in fact a shorter sleep may mean a better quality sleep."
The secret, according to the professor, is "discovering the sleep that you personally need, and then making that your sleep pattern."
Essential reading: Our full Beddit Sleep Monitor review
To gauge just how much shut-eye you need, it is worth analysing how you feel on different amounts of sleep. Do you wake up drowsy after nine hours and struggle to drag yourself out of bed, or are you more productive with an earlier start to the day?
As a general rule however, newborn babies need roughly 12–18 hours, kids could do with 10–11 hours, teenagers (contrary to popular myth) only need around 8.5 hours while adults manage on 7–9 hours a day.
How can we get more deep sleep?
According to Professor Espie "there are many small, practical steps you can take to make your day more sleep-friendly, from getting some exercise to cutting down on caffeine after lunch." But he recommends developing your own "personal wind-down routine."
Ideally this would consist of "an hour to an hour and a half before you go to bed when you don't do any work, avoid any 'stimulating' activity such as strenuous exercise, turn off any electronic devices and give yourself time to relax."
Easier said than done, especially if you like a night out and/or box set binges, but enjoying better sleep takes practice.
- As unrealistic as it sounds, try and get to bed by 9:30pm at least twice a week. It will help pay off your sleep debt and make work more productive.
- Avoid the lie-in at weekends as your internal body clock (circadian rhythm) doesn't stop for Saturdays. Force yourself out of bed and you'll sleep better during the week.
- Call last orders at the bar at least three hours before bed time to give your body time to process the alcohol. If your blood is clear of alcohol, you'll sleep more soundly.
How can you sleep more soundly?
"A reliable schedule is a critical part of being a healthy sleeper," suggests Professor Espie. "You should make the time to have a wind-down routine to help you relax before bed, and put your day to rest. Aim to stop your work/activity at least 60-90 minutes before bed, and keep your bedroom dark to help signal the body that it's time for bed."
"Give your mind something to focus on; one technique that's proven to work is using imagery. Imagine a scene that is calming and relaxing like walking through a favourite park or sailing in a gentle breeze – something that is engaging rather than exciting to the brain."
If you're unsure what to do with your sleep data, apps such as Sleepio sync with data from devices such as the Jawbone UP to help build a weekly plan – using CBT (Cognitive Behavioral Therapy) techniques – to help train your mind and body into sleeping better.
How can you fall asleep faster?
Worrying about not sleeping, the to-do list waiting at work or the state of your bank balance will keep even the heaviest of sleepers awake at night, but how can you get to sleep quicker? Follow these tips for a better night's kip:
- Bedtime routines aren't just for toddlers; a relaxing bath or listening to soft music can help you prepare for sleep.
- Turn down the thermostat as it is easier to sleep soundly in a cooler room.
- The more you exercise, the more likely you are to improve your sleeping patterns.
- Eat pumpkin seeds; they contain high amounts of zinc, which can help the brain convert tryptophan into serotonin which helps you sleep easier.
- Don't drink caffeine after lunch and go easy on the alcohol.
- Turn off your tablets as light from gadgets can inhibit and delay the production of melatonin, making it more difficult to get to sleep.
Be sure to check out our best sleep trackers and leave your own experiences in the comments.
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