According to a recent survey, 10% of those asked rely on a fitness/sleep tracker to tell them how many hours of shuteye they logged, the number of times they were restless and even how long they spent in deep sleep. But besides reading the log each morning, has tracking the data helped make changes to improve sleep? NYU School of Medicine researchers conducted a study in which an ethnically diverse group of 900 plus mobile phone users, 28 percent of whom used a health app that tracked their sleep, found that while self-monitoring sleep is a big business now, people don't really know how to interpret their sleep data. Or worse, if that data is even legitimate—and what we should do with it.
If you're concerned about a sleep issue, you might take the data to your doctor. “Since all of these apps are different and some may be more reliable than others, I'd take the information to your doctor or a sleep specialist and make sure that what you're seeing is accurate from a medical professional's standpoint." Otherwise, you don't want to make big changes to your sleep habits if you're just tracking data for fun.
The data needs to be continuous for at least a few weeks, and it should be collected during average nights where your sleep conditions were typical, not when the neighbors held that noisy shindig or your teen had a slumber party downstairs—nights you already know why you didn't sleep that well.
There are factors you can learn from sussing out your sleep data over time. Here are a few: Sleep Time. Most apps track time spent asleep. And it may be the most important data to consider. Since an average adult needs 7-9 hours of sleep nightly, tallying this data over time can alert you that you're consistently getting less than the optimal amount. Restlessness. “If you tend to move around at the same time every night, this could be a sign there is a consistent factor in your environment disturbing you," says Jessica Jones, the mattress expert at TheSleepJudge, like the neighbor's dog always barking at 3 a.m. This data provides a unique tool that can help you or your doctor examine disturbances in your sleep, especially if they're frequent or at the same time nightly. Slow Wave Sleep Time. Learning your percent of time spent in the slow wave part of your sleep is also helpful. “You want to aim for 20-25 percent," says Jones. Side effects of not getting enough deep sleep include increased cardiovascular disease, fatigue, depression and increased inflammation. Slow wave sleep is important because it is how the body recuperates many functions. Time to Fall Asleep Since it takes the average person about fifteen minutes to fall asleep after heading to bed, if your numbers are consistently longer, you may be heading to bed too early. Likewise if you fall asleep in mere seconds, it may indicate you're overtired and not getting enough shuteye. Right now interpreting your sleep data is a bit like an exploratory expedition in which by trial and error you arrive at your destination—a good night's sleep every night. You're looking for patterns and problems as well as gems like a solid eight hours with minimal restlessness. Certainly, if you have poor sleep or suspect a sleep disorder, this data can be useful in helping your doctor determine the best course. You can also use it to figure out and make small adjustments in sleep hygiene like moving your bedtime or improving the conditions in your environment.