Sleep Monitors: Should I Be Tracking My Sleep Cycle?
As insomnia and sleep conditions become increasingly more common, it’s no surprise that sleep technology is growing. In recent years, technological innovations have led to the rise of fitness tracker watches — many of which also have the ability to monitor and track sleep. Sleep trackers are widely touted for improving sleep hygiene, with many claiming to be able to determine the amount of sleep you attain each night, examine how much time you spend in each stage of sleep — light, deep & REM — and even reveal if you suffer from a sleep disorder.
But are sleep monitors as effective or necessary as they claim to be? Here, we assess the advantages and disadvantages of using a sleep tracker to better understand your sleep.
What are sleep trackers?
Sleep trackers monitor whether you’re asleep and calculate the amount of time you spend asleep. While most traditional ‘wearable’ trackers — typically in the form of a watch — monitor heart rate and movement during sleep, a growing range of ‘non-wearables’ can sit below or above your mattress, on a bedside table, or as an App on your phone. These devices use echolocation — a reflection technique that utilises low-power radio waves to measure snoring, breathing, and help you understand those trends over time.
Ultimately, it depends on your preferences as an individual. Some find wearable devices impede sleep due to discomfort. Others, however, find non-wearable devices can move around and may lead to inaccuracies if there’s a partner in bed.
How do sleep trackers monitor sleep quality?
The quality of your sleep (actigraphy)
Once you set your tracker to ‘sleep mode’, the main way sleep trackers determine your sleep quality is through monitoring heart rate and movement. Tossing, turning, changing positions and even getting up throughout the night (also known as actigraphy) can be picked up by fitness watches as key indicators of how well you are sleeping.
The quality of your sleep environment
Some sleep trackers examine other factors that can affect your ability to sleep, like the temperature of your bedroom or amount of light permeating through.
How much time you spend in each stage of sleep
Sleep trackers may be able to analyse the amount of time you spend in each stage of sleep. Collating this information, they will schedule your alarm to wake you up at the most appropriate time (when you’re likely to be in light sleep) making it easier to rouse in the morning.
Health and lifestyle metrics
How accurately can wearable fitness trackers measure sleep quality?
In general, wearable sleep trackers do a fairly good job of measuring sleep duration. One study even found that some of the wearable trackers showed more accurate sleep data than some research-grade sleep devices.i
While sleep tracking devices do a fairly good at tracking your total sleep vs. wake time, there is not enough evidence to suggest that they are fully conclusive in assessing your sleep stages. Since you make similar movements during light and deep sleep, there’s no way to accurately confirm what stage sleep you’re in. Only a comprehensive sleep study with a sleep specialist, or polysomnography, can reveal this information.
Should I be tracking my sleep cycle?
Limitations of sleep trackers
There’s evidence to suggest sleep tracking devices may incite anxious tendencies. In a 2017 study published in the Journal of Clinical Sleep Medicine, researchers discovered that sleep trackers could reinforce sleep-related perfectionism or anxiety — a condition otherwise known as ‘orthosomnia’.ii It’s widely acknowledged that anxiety already causes sleep disturbances and insomnia — so sleep trackers are not always recommended for those who experience anxiety or panic attacks at night.
Benefits of sleep trackers
Despite some limitations, many proponents of sleep tech advocate that health trackers can help to foster healthy sleeping habits. There’s a strong argument to suggest that tracking helps to form healthy habits: tracking food intake can lead to healthier food choices, tracking exercise can lead to better adherence.
For example, it may prompt you to ask important questions that interrogate your current patter: do you feel lethargic and sluggish when you sleep from 10 pm to 6 am, but energised if you shift your sleep schedule to 11.30 pm to 7.30 am? Do you sleep better on the days you exercise? Is your sleep disrupted if you have a coffee after lunch? By mindfully observing sleeping patterns with a tracking device, it may encourage you to make positive choices throughout the day that can benefit your sleep, such as exercising more or drinking less caffeine during the day.
If you’re keen to get some insight into your sleeping patterns and how to improve them, then a sleep-tracking device could be a helpful investment alongside maintaining healthy sleep practises. However, it’s important to take the data with a pinch of salt and be mindful that using your device doesn’t become an unhealthy habit.
For even more information on how to improve your sleep hygiene and wake up feeling energised, simply explore the rest of our sleep hub.
Lee. J., Byun. W., et al. (2019). Comparison of Wearable Trackers’ Ability to Estimate Sleep. International Journal of Environmental Research and Public Health. 15(6), p.1265.
Baron. K., Abbott. S., et al. (2006). “Orthosomnia: Are Some Patients Taking the Quantified Self Too Far?”. Journal of Clinical Sleep Medicine. 13(02), 351-354.
Olivia Salter has always been an avid health nut. After graduating from the University of Bristol, she began working for a nutritional consultancy where she discovered her passion for all things wellness-related. There, she executed much of the company’s content marketing strategy and found her niche in health writing, publishing articles in Women’s Health, Mind Body Green, Thrive and Psychologies.