How fitness trackers can help you sleep smarter

BATON ROUGE, LA (WAFB) - Some of our body's most vital functions happen while we're sleeping.

"It's one third of our life," explains sleep specialist, Dr. David Thomas. "We tend to underestimate the value of sleep and what it does."

Your body goes through several stages of sleep, including what's known as Rapid Eye Movement, or REM sleep, and three non-REM stages. Each sleep stage plays a different role in your health, from repairing muscles to boosting your immune system and helping your brain sort and store information. For more on what happens during each stage, click here.

A lack of sleep is associated with a lot of serious health issues, including heart disease, stroke, obesity, and anxiety disorders, in addition to poor overall function. It's no surprise, then, that smart watches and apps make it easier than ever to track your sleep. However, are these devices accurate?

The Spine Hospital of Louisiana and their sleep lab helped find some answers. During a sleep test, a patient spends the night in the sleep lab, a sort of high tech hotel room. The patient is hooked up to dozens of sensors that monitor brain activity, heart rate, breathing, oxygen rate, movement, and snoring.

"With all of that we just diagram their sleep architecture, determine what sleep stages they go through, which ones they perhaps don't go through, and what happens to them as it transitions through the night," explained polysomnographic technologist, David Dayries.

For our comparison, we added the popular fitness tracker, FitBit that, like most smart watches, uses movement and heart rate to track sleep. The results were surprising.

"When it comes to sleep efficiency, sleep onset, and sleep architecture issues, it's pretty accurate," said Thomas.

Using the sleep lab data as the gold standard, the Fitbit came pretty close. The sleep lab recorded a total of 396 minutes of sleep, which amounts to a little over six and a half hours. The Fitbit was only 17 minutes off, tracking a total of 379 minutes of sleep.

When it came to tracking the stages of sleep, the Fitbit wasn't quite as accurate, but it's close enough to give a good overall picture of the night. The results are below:

Sleep Lab FitBit
Stage 1 17.5 mins 39 mins
Stage 2 244 mins 244 mins
Stage 3 78.5 mins 60 mins
REM 56 mins 75 mins

According to Dr. Thomas, most sleep disorders are behavioral, meaning you do something during the day to affect your sleep at night. That could involve anything from diet to too much screen time. Thomas says that's how fitness trackers can help you sleep smarter.

"The advantage is that they can look for patterns and consistencies and if they keep a diary of their life, they will know that there's specific things they're doing during the day that are affecting their sleep," said Thomas.

However, the specialist emphasized that a fitness tracker cannot give a medical diagnosis or detect a medical issue, like sleep apnea. Thomas says if problems with sleep are affecting your everyday ability to function, you probably need to discuss those issues with your doctor.

For more information on the importance of sleep for your health, click here.

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