The average adult needs at least seven hours of sleep each night, though unfortunately many get a lot less. Approximately 70 million Americans have a sleep disorder, which may be why there's tremendous interest in popular fitness trackers that allow you to quantify and evaluate the quality of your sleep -- without the expense of a sleep specialist.
Personal sleep trackers seem like a great investment for anyone suffering from insomnia or sleep deprivation. But are they accurate?
"The reason why these devices are so good is it puts greater emphasis on sleep," Michelle Primeau, clinical instructor at the Stanford Center for Sleep Sciences & Medicine told CNET reporter Sumi Das. "Most adults in the U.S. are somewhat sleep deprived."
Fitness trackers with sleep tracking capabilities, such as Fitbit, work by keeping track of how much you toss and turn in your bed to provide data on your sleep quality. This is done with accelerometers.
"They are measuring an indirect approximation of sleep through movement," said Primeau. "In order to make these estimations of deep or light sleep they are probably using an algorithm that takes into account the relative amount of movement that a person is having in the course of a night."
On the other hand, sleep specialists base their treatments and diagnoses on polysomnography, a special multifaceted test that typically involves sleeping in a controlled environment -- a sleep lab -- hooked up to plenty of wires. This gold-standard for sleep specialists measures everything from your brain activity, heart rate and breathing to your eye and muscle movements. Polysomnography generates far more information than currently any personal sleep tracker can, and is used to diagnose problems such as sleep apnea, circadian rhythm disorders, nighttime movement disorders and other health issues.
"Polysomnography is a collection of different physiological measurements that we use to define and characterize sleep," explained Primeau. "We start with EEG which are little electrical wires that measure your brainwaves. It also includes measures like a snore mic. Belts around you chest and abdomen will also record your breathing."
But some experts argue that sleeping in a controlled setting, such as a sleep lab, messes up the evaluation before it even has the chance to begin, since the person won't sleep the same as in their own bed. In general, a personal sleep tracker could be a good starting point for a better night of sleep, but these devices may not be enough to diagnose and solve your shuteye challenges.
If you're desperately tired but still skeptical, a sleep app for a smartphone may be a good place to start, since it will only set you back a few dollars compared with a hundred or more for a tracker device. Sleep Cycle, Sleep as Android and Sleepbot operate on the accelerometers built into a phone.