Don’t rely on a sleep tracker to improve your sleep on its own. Wearable fitness and sleep-tracking devices, such as Fitbit and the Apple Watch, can help people set goals and track their sleep behaviors but also promise more than they can deliver. They cannot really measure stages of sleep or determine the difference between light sleep and periods of wakefulness. But because they seem to quantify sleep—and sleep seems to be quantifiable, with the common recommendation to get eight hours per night—some people use the devices for goal-setting. That means they go to bed with the goal of finding the next morning that the tracker displays a certain amount of a certain type of sleep.
But for some that behavior produces stress and anxiety that make it harder to get restful, restorative sleep. It can lead to a preoccupation with perfecting sleep, which has been called orthosomnia, which means correct sleep and is similar to the preoccupation with healthful eating called orthorexia. In fact, this fixation on potentially inaccurate or incomplete data can make it harder for therapists to help people with insomnia. Even if much more accurate laboratory sleep studies show deep, restorative sleep, a sleep tracker may indicate that total sleep “restless.” A patient who believes that may not respond to treatment—or medical reassurance.
Sleep trackers can even reinforce poor sleep habits by encouraging people to spend more time in bed. That is typically the opposite of what sleep therapists recommend for people who have difficulty falling asleep or staying asleep.
The trackers are already used by 15% of US adults, and another 50% have said they might consider buying one. So the problem of orthosomnia is likely to grow. Self-defense: Realize that even for the best of sleepers, there are ups and downs, good nights and bad nights, restful and less-restful sleep periods. That is entirely normal. And don’t depend on a fitness/sleep tracker to tell you what’s really happening with your sleep.