Fitbit Versa: Effective Sleep Tracker Or Gimmick?

Fitbit's sleep tracking feature has been a topic of interest for many users, with some praising its accuracy and others questioning its reliability. The Fitbit Premium Sleep Profile provides a detailed monthly analysis of sleep metrics, including REM sleep, restorative sleep, sleep stability, and sleep schedule variability. The sleep tracking function is available on various devices, including the Fitbit Versa 4, and can be accessed through the Fitbit app. The app offers a tutorial with helpful information, such as the recommended fit of the band. Fitbit's sleep tracking uses a combination of movement and heart-rate patterns to estimate sleep stages, with the goal of providing insights to improve sleep quality.

Fitbit Versa 4 sleep tracking

The Fitbit Versa 4 has a sleep-tracking function that works by monitoring your sleep stages and providing a detailed analysis of your sleep quality and quantity. The device can track the duration of your sleep and, if it has a heart rate monitor, it can also discern between light sleep, deep sleep, and REM sleep.

To use the sleep-tracking feature, simply wear your Fitbit Versa 4 to bed. The device will automatically recognize when your body is going into sleep mode and start logging your sleep. The data collected includes how long you were awake, your restlessness, and your sleep stages. This data is then used to generate a nightly Sleep Score, which gives you an at-a-glance sense of how you slept.

For more detailed insights into your sleep, you can subscribe to Fitbit Premium. This service provides a monthly Sleep Profile, which offers a more comprehensive analysis of your sleep beyond just the duration. The Sleep Profile takes into account various factors, such as REM sleep, restorative sleep, sleep stability, nights with long awakenings, and days with naps. It also assigns you a Sleep Animal avatar, such as a bear, dolphin, or giraffe, based on your sleep metrics.

To ensure the most accurate sleep tracking results, it is recommended to wear your Fitbit Versa 4 moderately snugly and higher on your wrist, toward your elbow. Additionally, allow for a few days of usage to let the device learn about your body and provide more precise data.

Sleep stages and accuracy

Sleep tracking has been a feature of Fitbit devices since their early days, and the company has consulted and partnered with leading sleep experts to develop their technology and improve their processes. The Fitbit Versa 2, in particular, has been described as a "really good sleep tracker".

The Fitbit Versa infers when you’re sleeping and what stage of sleep you’re in using an accelerometer (an instrument for measuring bodily accelerations of the wrist) coupled with a technique called optical photoplethysmography, or PPG. PPG measures blood flow based on how green light from an LED on the back of the watch is reflected by the body. The watch also uses motion data and heart rate data to show you time spent in various sleep stages (light, deep, and REM).

Fitbit devices that track heart rate (except Charge HR and Surge) also track sleep stages. When you sync your device each morning, you can review your sleep data, such as your sleep score. You can check this information on your Fitbit device or in the Fitbit app. You can check your averages for the week or longer periods of time for certain sleep stats, including hours slept, sleep score, sleep schedule, and sleep stages.

The Smart Wake feature monitors your sleep stages and wakes you during a Light Sleep stage, in a window of up to 30 minutes leading to the time you’ve set for the alarm. The Sleep Score is made up of time asleep (50% of the score), the amount of time you spent in deep and REM sleep (25% of the score), and restoration (which shows how much of your sleep time is below your resting heart rate, also 25%).

According to a paper published by Fitbit scientists in 2017, the watch’s sensors can classify sleep stages with 69% accuracy in any given 30-second time window. If you’re thinking this accuracy is low, well, that depends on the context. It’s true that Fitbit’s sleep staging is only correct in these 30-second blocks slightly more than two-thirds of the time and, moreover, this fact is not communicated to users in the Fitbit app. So, if you only use Fitbit for one night, take the app’s sleep staging with a few grains of salt.

Some have raised legitimate concerns about the accuracy and/or value of sleep-tracking devices, and particularly wrist-based sleep trackers. Sleep scientists say that sleep staging information, while it can be interesting, should be taken with a grain of salt. A wrist-worn sleep tracker like the Fitbit can’t measure your brain’s electrical activity directly in the same way a laboratory sleep study does, where a patient wears an array of electrodes. Your Fitbit, like most wearable sleep trackers, is using other metrics, like physical movement, pulse rate, and breathing, to infer which stage you’re in, so it may be less accurate.

Fitbit Premium Sleep Profile

The Sleep Profile consists of three components: a monthly sleep analysis based on ten key sleep metrics, a Sleep Animal, and education and guidance. The monthly sleep analysis is derived from a month-long analysis of your sleep, which consists of three main components: your monthly sleep analysis, Sleep Animal, and education and guidance. The Sleep Animal feature assigns you a "sleep animal" that represents your rest-related habits. There are six Sleep Animals, each representing a distinct sleeper type. For example, a Bear tends to have a consistent sleep schedule and falls asleep around the same time, whereas a Dolphin tends to fall asleep later and sleeps for less time overall.

The Fitbit device tracks your sleep by using a combination of your movement and heart-rate patterns. When you haven't moved for about an hour, your tracker or watch assumes that you're asleep. It also tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV), which fluctuates as you transition between light sleep, deep sleep, and REM sleep stages.

The Sleep Profile feature is intended to help you understand your sleep patterns and make informed decisions to improve your sleep quality over time. It is not intended for medical purposes, and users are advised to consult their healthcare professional for questions about their health.

Smart Wake feature

The Smart Wake feature is available for the Ionic and Versa series smartwatches. It is a function that allows the user to set a range, for example, 30 minutes, during which the watch monitors the user's sleep and wakes them up at the most optimal time within that range. The Smart Wake feature is not dependent on the Bluetooth connection between the Fitbit and the phone. However, it is important to note that the Smart Wake feature may not be available on all Versa models, and it requires the latest Fitbit OS 4.1 (70.7.14) update.

The Fitbit sleep tracking feature provides a detailed analysis of sleep patterns, including sleep stages such as REM, Deep, and Light sleep. It also tracks restlessness, sleep duration, and heart rate variability. The data is used to generate a nightly Sleep Score and a monthly Sleep Profile, which includes information on sleep schedule variability, restorative sleep, sleep stability, nights with long awakenings, and days with naps.

The Smart Wake feature is designed to wake the user during a light sleep stage within the set range, which can help them feel more refreshed and less groggy upon waking up. It is important to note that the feature may not work accurately if the Fitbit device cannot get a detailed heart rate recording. Additionally, the Fitbit device should be loose enough to slide up and down the wrist for optimal tracking.

The Smart Wake feature has been well-received by users, with some reporting that it has changed the way they wake up in the morning and made them less grumpy. The gentle vibration of the Fitbit device, instead of a loud alarm, is also appreciated by users. Overall, the Smart Wake feature, combined with other Fitbit features, can help improve sleep habits and overall health consciousness.

Fitbit battery life

The battery life of a Fitbit device depends on its model, usage, and settings. For instance, the Charge 5, Charge 6, Inspire 3, Sense 2, Versa 2, and Versa 4 models have a battery life of up to 3 days. Meanwhile, the Luxe, Sense, and Versa 3 models have a battery life of up to 2 days. The Charge 4, Charge 5, and Charge 6 models can last up to 5 hours, while the Ionic model can last up to 10 hours. The Sense, Sense 2, Versa 3, and Versa 4 models have a battery life of up to 12 hours.

The Fitbit Inspire 3 can last for up to 10 days when fully charged. Similarly, the Fitbit Versa has a battery life of up to 4 days, and the Fitbit Inspire can last for up to 10 days.

Certain features and settings can impact the battery life of a Fitbit device. For example, using the GPS or notification functions can drain the battery more quickly. Additionally, using the always-on display and tracking SpO2 data can also reduce battery life. To conserve battery life, it is recommended to turn off or reduce the use of certain features, such as the always-on display, and to avoid extreme temperatures when wearing or charging the device.

Frequently asked questions