_There are an ever-increasing number of apps and wearable devices on the market that aim to provide us with insight into our sleep. But are they actually doing more harm than good? _
The accuracy of sleep trackers
Consumer sleep trackers typically measure sleep by analyzing data based on an individual's movement during the night.
On the surface, the theory behind this seems sound. If you're tossing and turning during the night, it's fair to assume you're not sleeping. However, nighttime movements are a simplistic metric.
We don't always move when we wake. For example, someone with a sleep disorder such as insomnia or sleep apnea may wake several times during the night, but they won't always move during these periods of wakefulness.
Some sleep tracking devices even aim to help you wake at a time that's right for your body, based on where you are in your sleep cycle.
Unfortunately, such devices can't reliably account for any sleep disturbances during the night, and it's just not possible to record sleep stages by movement alone, because sleep stages are governed primarily by brain activity.
Some wearable devices can track heart rate, which can make them more accurate, but the fact of the matter is, unless you're recording brain waves, it's just not possible to accurately determine optimal wake times or when you are truly asleep.
Although wearable devices can provide useful information about sleep in those with healthy sleep patterns, my concern is that those with sleep problems may use them in an attempt to improve their sleep — and their lack of accuracy for such individuals in particular is problematic.
Indeed, a study published in Sleep Medicine Reviews found that activity-based monitoring is less useful for those who have long motionless periods of wakefulness (typical in those with insomnia) or those with a disorder that affects their movements (such as sleep apnea and restless legs syndrome).
Interpreting the data from sleep tracking devices
When someone with a sleep issue is presented with the data recorded and interpreted by their sleep tracking device the following day, it can lead to unnecessary worry and anxiety.
This, in turn, can make sleep more difficult.
Reducing fear and anxiety toward sleep is one of the primary aims of the free sleep training course I created to help insomnia sufferers improve their sleep without sleeping pills.
When I work with insomnia sufferers on a one-to-one basis, I ask them to record their sleep using a sleep diary. I can usually tell who is using a sleep tracking device because they will record extremely specific numbers for the exact time they fell asleep, the exact number of times they woke during the night, the exact amount of sleep they got, and the exact time they woke.
Those who do not use these devices typically record an estimate based on their memory of the night — and they usually report fewer awakenings and more time asleep.
Those with insomnia are already concerned about their sleep. Using a device that presents data that's potentially worse than they suspected (regardless of accuracy) can increase sleep anxiety, making sleep more difficult.
Furthermore, if a device reports data that's better than expected, it could lull someone with a potentially serious sleep disorder into a false sense of security.
The alternative to sleep trackers
For healthy sleepers, sleep trackers can help bring more attention to the importance of sleep and encourage good sleep hygiene. That's a good thing.
However, for those with a sleep disorder, their accuracy is questionable and the data they report back can increase stress and anxiety, making sleep even more difficult.
If you suspect you are living with a sleep disorder, you should speak to your doctor, who may recommend a sleep study. This involves laboratory polysomnography, also known as a sleep study, which is still the most accurate way to measure and record sleep.
Martin is the creator of Insomnia Land’s free sleep training for insomnia. His online course uses CBT for insomnia techniques to help participants fall asleep and stay asleep. More than 4,000 insomniacs have completed his course and 97 percent of graduates say they would recommend it to a friend.