Sleep tracking devices: How well do they work?

People are wearing them on their wrists, tucking them under their mattresses and placing them next to their pillows when they go to bed. Sleep tracking devices are becoming increasingly popular – but just how effectively do they measure how well you sleep?

According to John Cronin, M.D., a sleep medicine specialist and medical director at the Scripps Clinic Viterbi Family Sleep Center, these devices can be useful for tracking your sleep schedule – when you go to bed and wake up – but are less reliable for measuring the quality of your sleep.

“Wrist worn devices generally measure movement, with the notion that your movement in bed correlates with wakefulness,” Dr. Cronin said.  “They can track how much you move, but are not directly measuring sleep, which is generally a brain measurement (electroencephalogram).”

There’s no question that adequate sleep is important to your health and well-being. A lack of quality sleep can result in a range of problems, such as fatigue, difficulty concentrating, slowed response times, headaches and irritability. Moreover, research has shown that insufficient sleep may play a role in more serious health problems, including obesity, heart disease and a weakened immune system. So when sleep tracking devices indicate poor sleep, is there cause for concern?

“I’ve had many patients come in who are concerned about the numbers on their tracking devices, but the numbers rarely provide meaningful information that I can use to make a diagnosis,” Dr. Cronin said.

Dr. Cronin describes an overnight sleep test held recently at the Scripps Clinic Viterbi Family Sleep Center. The patient wore both a consumer sleep tracking device and the standard monitoring equipment used in clinical polysomnography tests to diagnose sleep disorders; the clinical equipment monitors heart rate, breathing, movement, core temperature, blood oxygen level and brain waves. The tracking device reported that the patient barely slept, but the brain wave analysis indicated he actually slept very well.

Another concern with sleep tracking devices is the lack of information about how they process data.  Each company has a proprietary algorithm that analyzes the data, so it can be difficult to evaluate how they work or how they compare to one another. In contrast, the devices used in clinical sleep studies use published algorithms and proven research that have been widely reviewed by experts in the field.

While sleep trackers can encourage you to pay attention to your sleep habits, they also can lead to anxiety about quantity and quality of sleep—and this can make it even more difficult to get a good night’s sleep.  This reality often works against patients who suffer from insomnia and have significant anxiety about their sleep.

“I always encourage patients to be proactive about their health and wellness, so I don’t discourage patients from using sleep trackers. But I caution their expectations of what they will get out of it,” Dr. Cronin said. “During sleep you’re unconscious, so it is difficult to do something to actively sleep better. You can do things to improve your sleep environment, scheduling and habits which can have an important role overall. It’s not clear that these devices can capture these impacts yet.”

Dr. Cronin believes that as sleep tracking technology improves, so will the results and their use in getting a better night’s sleep. In the meantime, you can take steps to create a peaceful, supportive sleep environment. Here are several tips to try:

• Minimize light and sound in your bedroom. Try wearing an eye mask or playing peaceful nature sounds to help you drift off.

• Go to bed and wake up at about the same time every day, even on weekends or days off, to help establish a consistent sleep schedule.

• Exercise can help improve sleep, but avoid strenuous exercise within two hours of bedtime.

• Avoid using electronic devices such as computers, mobile phones and tablets within an hour of bedtime, as the light can confuse your brain into thinking it is still daylight.

• Keep your bedroom temperature comfortable—not too warm or too cold.

• Avoid caffeine after noon if you have problems falling or staying asleep.

• If you drink alcohol, it may affect your sleep quality. You may fall asleep faster, but you are more likely to awaken in the middle of the night.

If you repeatedly have problems going to sleep or sleeping through the night, it’s a good idea to call your doctor. He or she can check for underlying causes and help you get the rest you need.

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