A hefty amount of skepticism surrounds sleep tracking apps and devices in the United States. Only 8% of adults regularly track their sleep and 9% occasionally track their sleep. What’s stopping the rest of the population from tracking their sleep data to improve their health? It’s certainly not lack of interest, as 45% of adults report they can imagine themselves tracking their sleep, but don’t. If you’re thinking of taking the plunge into the world of sleep tracking, here’s what you need to know.
How they work
It’s important to remember that sleep trackers don’t actually measure sleep – they measure activity. Based on the assumption that you are generally active while awake and inactive while asleep, sleep trackers measure your body movement to assess your state of consciousness. To do so, wearable sleep-tracking devices use an actigraph sensor and sleep-tracking apps measure your body movement with an accelerometer, a small motion sensor built into most smartphones (some wearable sleep trackers use an accelerometer, too).
Some sleep tracking apps and devices may also use a microphone to detect noise from your body (i.e. movement or snoring) and your environment, a thermostat to determine the impact the temperature in your bedroom has on your sleep quality and a heart rate monitor to make a more educated assessment of when you are in REM sleep.
Consequently, sleep trackers are not entirely accurate. A person who experiences excessive motion even in deep sleep may be informed their quality of sleep is poor (or nonexistent) and a person lying very still in bed lamenting the fact they can’t fall asleep might be perceived by their sleep tracking device to be in a deep slumber.
What they monitor
That doesn’t mean the data sleep trackers collect isn’t useful. Many sleep trackers exist on the market, but they generally monitor several common sleep metrics:
- Sleep duration – Based on the metrics your sleep tracker uses to determine when you are actually asleep (movement, noise and heart rate), your sleep tracker estimates how long you slept overnight.
- Sleep phases – Some sleep trackers monitor the phases of your sleep and set your alarm for a period of light sleep, making it easier for you to wake up.
- Interrupted sleep – Interrupted sleep is sleep plagued by long periods of waking up throughout the night.
- Environment – Some sleep trackers analyze the quality of your sleeping environment based on factors like light, noise and temperature.
- Lifestyle – Some sleep trackers may collect information about your daily activity that can impact sleep quality, like caffeine consumption, eating habits and exercise.
How can you use the data sleep trackers provide?
So you collected data on the duration of your sleep, your sleep quality, the length of your sleep phases and more. Now what? Sleep trackers are not a replacement for a medical sleep study, but they can help you recognize patterns in your sleep habits and make small daily adjustments to improve your quality of sleep. For example, is your sleep disrupted when you drink coffee after lunch? Do you sleep better when you exercise in the morning or at night? Do you experience more interrupted sleep the higher the temperature is in your bedroom? All of these patterns can be detected by sleep tracking apps and devices to inform your lifestyle and habits to optimize your sleep. Tracking your sleep may also clue you into the potential of an underlying sleep disorder. If you suspect factors beyond habits and lifestyle may be negatively impacting your sleep, see a physician to schedule a medical sleep study.