A good night’s rest can do wonders for your health, and these days, there are a ton of devices that promise to help you improve the quality and quantity of your sleep simply by tracking it. However, many of these devices just shove data into your face without giving you any advice on how to use the numbers to change your habits — though sleep experts say when used properly, sleep trackers can be a great tool.
Why should you track your sleep? Doing so can not only help you stay awake during that midday meeting, but also help you avoid some serious health problems, says Beth Malow, chief of Vanderbilt University Medical Center’s Division of Sleep Disorders. “When we don’t get enough sleep, seven to eight hours every night, we feel worn down,” she says. “Our brains don’t function as effectively, we don’t think as clearly and we tend to be more cranky or moody. But there are also a bunch studies that link not sleeping enough to diabetes and obesity because a poor night’s sleep affects our metabolism.”
The first step to making the most out of your sleep tracker is to understand that it’s not perfect, says Brandy Roane, a behavioral sleep specialist with the University of North Texas Health Science Center. “They’re only as good as the algorithms used,” she says. “Don’t marry yourself to the numbers it’s giving you because several factors can affect them. Instead, use the numbers as a guide.”
While some devices are only for tracking sleep, they don’t necessarily do a better job than fitness trackers, which often have the function built in, says Roane, who recommends using either the Fitbit Flex or Jawbone UP.
Trackers typically overestimate the amount of time you sleep, Roane says, and a good rule of thumb is to subtract a half-hour to hour off the amount of time it says you slept. “You typically have to set the device when you go sleep and let it know when you wake up,” she says. “We often spend time in bed that isn’t sleeping. It can take anywhere from five to 15 minutes, or longer for some people, to fall asleep, which it doesn’t take into account.”
The trackers also tend to exaggerate how often you wake up during the night. “What it’s doing is using the movement of the device to determine if you’re likely asleep or likely awake,” Roane says. “If you have a bed partner, like a spouse or pet, if they move around near the device it might pick up that activity and think you’re awake.”
Once you understand the caveats of these devices, you can begin using the data they give you to make changes in your patterns, which starts by being more aware of your sleep habits, Malow says. “The devices give you as sense of how much sleep you get and how restless you are at night,” she says. “Looking at the data can help you notice that every time you have coffee after 2 p.m. you are more restless that night.”
You should look at the data documenting the time you go to bed each night, Roane says, and try to establish a set bedtime every night. “If you notice there’s a lot of variability in the times, try to set up a consistent time to go to sleep and wake up,” she says. “Constantly varying the time can lead to ‘social jet lag’ and can make you feel like you’ve just traveled across multiple time zones.”
You can also use the data to start a conversation with your doctor about your sleep habits, Malow says. “When people bring me their records, what I find is that it enables us to have a different kind of conversation,” she says. “They’re more engaged, they’re more interested and that makes them more likely to make a change.”
However, there are some things your device can’t tell you, which can also have an impact on the quality of your sleep. “They don’t look at light levels or noise, which can be very disruptive,” Roane says. “If you have ambient light from electronics or a TV, it can cause you to wake up frequently.”
In addition to sleeping in a room free of ambient light, Roane recommends using your bed only for sleeping, not reading or eating, and not allowing pets to sleep with you — as hard as that may be. “Animals get up and move frequently during the night, which can cause you to wake up often,” she says.
If you put all these tips and tricks together, Malow says, you’ll feel better in no time. “The more you’re aware of your sleep and the more you make a point to get the rest you need,” she says, “the more benefits you’ll see.”