Fitbit Sense review: A half-baked smartwatch for the wellness warrior

With fitness and stress management tracking, the Fitbit Sense is aiming to be the all-in-one smartwatch.

Sept. 22, 2020

Fitbit Sense review: A half-baked smartwatch for the wellness warrior

It's taken almost four years, but it feels like Fitbit has finally found its footing in the world of smartwatches and the Fitbit Sense is proof — sort of.

At this point, it's no secret that Fitbit is extremely capable of manufacturing accurate, easy-to-use, sleek, and affordable fitness trackers. But when it comes to smartwatches, it's safe to say the journey hasn't been as smooth.

Between 2016 and 2017, Fitbit released two devices that straddled the line between smartwatch and fitness tracker: the Blaze and Ionic. While both packed every sensor necessary to track your daily fitness needs, each one was just as clunky and unattractive as the one before it. These just weren't wrist-worn accessories anyone really wanted to wear on a daily basis.

And then came the Fitbit Versa in 2018, which the company confidently touted as a full-fledged smartwatch to compete with the likes of Google's Wear OS and Apple Watch. This time around, Fitbit prioritized design, resulting in a stunning device that lacked any standout features to separate it from the rest of the company's fitness trackers.

Now, with the new Sense, Fitbit's tapping into something that smartwatch brands have yet to even touch with a ten-foot pole: tracking the mind in addition to the body. Currently on pre-order, the $330 smartwatch packs an electrodermal activity (EDA) sensor under the hood to measure changes in skin temperature. With this device, it's clear Fitbit is signaling to the market that mental health and stress management are just as critical to track as fitness.

A premium, but subtle design

At over $300, the Fitbit Sense is the company's most expensive smartwatch to date and it's easy to tell from the packaging alone. I've unboxed many Fitbit fitness trackers and smartwatches throughout my career, but nothing has felt quite like opening the double-door box that houses the Sense. It's a beautiful-looking watch that's super lightweight, comfortable to wear throughout the day, and pairs well with any outfit.

The gold aluminum watch case has a large, 1.58-inch AMOLED display with 336 x 336 pixel resolution. The Sense's display, bordered by thick bezels all around, is super responsive and smooth. It's also bright enough to easily view content and metrics even while in direct sunlight. It also comes with an always-on display feature, so you can glance at it to view the time or metrics without having to flick your wrist to wake it.

I can get used to not having any physical buttons on future Fitbit smartwatches.

Navigating the display is easy to get the hang of, too. Swipe down to view notifications; swipe up to access all of your health metrics and stats; swipe to the left for access to apps (i.e., exercise, weather, Fitbit Pay, Spotify, and more); and swipe right to toggle on features like Do Not Disturb, Always-on display, Sleep Mode, and more.

The Sense, which is free of any physical buttons, features a sensor button with haptic feedback that's indented on the left side of the case. A single press wakes the screen; a double press gives you access to four of your favorite pre-selected apps; and a long press brings you to one specific app. It's just as easy as using a physical button and also gives the Sense a more streamlined look.

On the bottom of the Sense, you'll find a variety of sensors including Fitbit's new heart rate monitor, electrical sensors for EDA scans, and a skin temperature sensor. Additionally, the smartwatch also packs an altimeter, gyroscope, 3-axis accelerometer, built-in GPS, and an SPO2 sensor.

The right side of the Sense's case packs a speaker while the opposite side includes a microphone — both of which are used for either Google Assistant or Amazon Alexa. But there are a few things to note about this voice assistant feature.

The Fitbit Sense packs a ton of different sensors.

For starters, until Fitbit adds Google Assistant functionality later this year, you're limited to using Alexa for now. Additionally, audible assistant replies also won't available until later in 2020, so the speaker is useless at the moment. As of right now, you're forced to open the Alexa app on the display, ask the question out loud, and then wait for the results to appear on the screen. It's not awful, but seeing as how I'm used to hearing Alexa on my Amazon Echo or even Siri on my iPhone provide me with verbal results, it takes a bit of readjustment.

As for accessories, the Sense does have interchangeable straps. Out of the box, it comes with a classic silicone wristband. But you can purchase additional bands like the breathable sport band or woven band, which range anywhere from $29.95 to $49.95.

Accurate fitness tracking, unpredictable heart rate monitor

Compared to other Fitbit smartwatches and trackers, the Sense doesn't offer anything new in terms of exercise tracking features. On a daily basis, it tracks steps, distance, calories burned, heart rate, and floors climbed. Using the exercise app, you can track a variety of different workouts like running, biking, walking, hiking, yoga, and more.

The Sense also includes the fairly new Active Zone minutes feature, which was first introduced with the Charge 4 back in April. Essentially, it measures your heart rate zones (i.e., fat burn, cardio, and peak) to give you an extra push throughout your workout. So, when you're in fat burn zone, you'll get one credit towards your total Active Zone minutes while the more intense zones will get you two credits.

I didn't have the best luck with the heart-rate monitor on the Sense.

To do this, the Sense uses Fitbit's new PurePulse 2.0 heart rate monitor, which the company says has an improved algorithm to offer its "most advanced heart rate technology yet." However, I didn't have the best experience with it during my workouts.

To test it out, I wore the Sense, Apple Watch Series 6, and Polar H10 heart rate monitor, and compared my stats. Throughout three separate runs, I found my average heart rate on the Sense was always off by about 10 to 20 beats per minute (BPM). Now, contrast that with the measurements from my Apple Watch and Polar strap — both of which were only about one to two BPM off from one another.

Throughout my runs, I noticed the Sense struggled to keep up with change in pace in real-time. For example, when I was at a light jog, the BPM on the Sense matched the rest of the devices. But when I'd ramp up my speed and increase my heart-rate, it would take a while for it catch up with both the Apple Watch and the Polar H10.

I also tested it during a quick, 15-minute kickboxing session and ran into the same issue. But this time, the average BPM was off by about 20 BPM.

While this might not be a big deal for some people, it's important for those who base their training around heart rate zones. Seeing as how they rely on the exact zone their body is in to decide whether or not to slow down or speed up, it's crucial for proper training.

I didn't have this issue throughout the day, though. Resting heart rate calculations were spot on with results I typically receive from other trackers. However, it clearly tends to struggle with more intense activity when there's various changes in heart rate throughout the workout.

With built-in GPS, at least distance tracking was accurate.

I reached out to Fitbit to look into the heart rate monitor issue and will update this review when I receive a response.

With built-in GPS, distance tracking was almost on par with the Apple Watch's results. Having that built-in sensor also means you don't have to take your phone with you on your runs in order to log your mileage. You can also pair Bluetooth headphones to the device and access playlists from music apps like Spotify, Pandora, and Deezer.

Managing stress with the Sense is going to take some work

Using the Sense, you can track how stressed out you are throughout the day or night. Simply open the EDA Scan app on the device, place your palm over the metal frames around the display, and breathe for two minutes while it takes a Quick Scan. When it's done, you'll feel the Sense vibrate and you'll be provided with a summary of your session. Basically, it works like this: The higher the number of responses it records in one session (based on your change in temperature), the more stressed you are.

To take an EDA Scan, all you have to do is place your palm over the display.

You'll then be asked to log how you're feeling (i.e., very calm, calm, neutral, stressed) so that the Fitbit app can connect a specific mood to your score. At the moment, logging your mood simply allows you to make more sense of your overall score when reflecting back. But in the future, that data might also make it easier for your Fitbit to predict stress levels based on your EDA Scan.

With that EDA Scan, you'll also receive a Stress management Score (based on numbers 1-100) that's calculated using your EDA score, heart rate, sleep quality, and activity levels. The higher the score, the less stressed out you are.

While I can't measure the accuracy of these EDA scans, I did rely on the feature whenever I was feeling a lot of anxiety coming on. And I can confirm that, for most sessions, it managed to pick up a higher amount of responses the more stressed out I was. And, given that the week prior was absolute madness work-wise, I'd say my lower score of 49 last Thursday and 62 today are very accurate indicators of how I'm feeling on the inside.

As of right now though, I can't say the score impacts my daily life very much when it comes to how I view my metrics or what workouts I'm going to do. And, that's particularly because getting the most out of the EDA Scans and your Stress Management Score is going to take some work and dedication.

Taking the time to breathe for two minutes throughout your day is mainly a push towards guiding people into the habit of meditating. If you'd rather opt for a shorter or even longer EDA Scan, the bottom of the display suggests participating in a mindfulness session ranging anywhere from one minute to an hour.

Using the Fitbit app, you can see a history of your Stress Management Score.

When you tap on a specific score, you can log additional reflections throughout the day.

There's absolutely nothing wrong with that — if it's not already incorporated into your routine. I've been incorporating meditation into my fitness routines since the start of the pandemic, so the EDA feature was actually crucial for days when I felt anxiety attacks coming on. I would simply open the app, breathe for two minutes, and log my score.

It's worth noting that relying on meditation whenever I start to feel panicky has taken me over six months of practice — and I'm still working on it. While you can set notifications for reminders to take a moment to breathe, the actual act of stopping what it is you're doing to take a reading each time might take practice for some.

But given the positive benefits that mindfulness and meditation can provide for some, it's certainly a nice feature to have, especially if it also helps paint a picture of your overall stress. Of course, it's going to take some time to evolve before we can see it provide more useful suggestions and metrics.

A smartwatch that's also an ideal sleep companion

Though the heart-rate monitor had a tendency to struggle with workouts, it did manage to track sleep accurately. Based on my BPM, it was able to correctly pinpoint when I fell asleep and when I woke up — a problem a lot of smartwatches and trackers tend to misidentify. It also provided me with a Sleep Score each morning based on metrics like duration of sleep and sleep stages (i.e., REM, deep, and light sleep).

The Sense offers a watch face that lets you easily check your blood oxygen level from the night prior.

The Sense also tracks your temperature throughout the night. It doesn't provide you with your exact temperature, but it does keep an eye on whether you're above or below your baseline. It takes up to three days of wearing the device to bed for it to determine your standard body temperature, and from there it calculates whether you're in range.

While it's especially useful during a pandemic where a high fever is one of the symptoms of COVID-19, these numbers can also help you figure out whether you're coming down with any illness. And, for women, specifically, it can help indicate whether or not a new menstrual cycle is starting.

Of course, it's tough to measure accuracy when it comes to this feature, but I can confirm that it registered when I was feeling warmer than usual one night. I'd gone to bed wearing both a T-shirt and a sweatshirt, and took off the latter because it was way too hot in my room. The next morning, the Sense recorded that I was .3 degrees Fahrenheit above my baseline. The increase in temperature also makes sense since my next menstrual cycle is supposed to start in about three days.

The last metric the Sense tracks throughout the night is your blood oxygen levels using the SPO2 sensor. Unlike the Apple Watch Series 6, which allows users to measure their levels manually, the Sense measures it throughout the night instead.

Fitbit says the reason it doesn't offer the ability to measure your levels on demand is because nighttime"is when your body is most likely to show variations from your baseline oxygen saturation levels."

You can see your history of temperature readings on the Fitbit app.

After three days, it was able to compare my metrics each night to baseline reading.

I also used the SPO2 watch face that displayed my levels after each night of sleep. That way, all I had to do was sync my watch to the Fitbit app each morning and the reading automatically appeared.

Similar to the new Apple Watch Series 6, the Sense also packs an ECG sensor, however, that feature won't be available until October since Fitbit only recently received FDA clearance this month. To take a reading when it's enabled, you'll need to place your fingers on the corners of the watch for 30 seconds to determine if you show any signs of atrial fibrillation.

Iffy battery life, depending on how you use it

Though Fitbit is very much known for its impressive days-long battery life, the Sense is a tad disappointing on that front. It's understandable, however, seeing as how the Sense is technically tracking double the amount of information as compared to Fitbit's other smartwatches — and that's with the addition of EDA scans.

The Fitbit Sense is supposed to last up to six days, but I could only squeeze about three to four days out of it on a single charge.

When it first arrived last Tuesday, it lasted me up until Friday night after using it for a couple of quick workouts, sleep tracking, and taking a few body scans throughout the day. That was also with the always-on display and all notifications enabled.

After charging it again on Friday, I was at 14 percent by Monday afternoon, but that was after making some tweaks. Since I'd used it for hour-long workouts throughout the weekend, along with more EDA scans to track stress, and sleep tracking, I saw it deplete at a much faster rate than earlier in the week. So, I turned off the always-on display and limited my notifications to strictly Gmail, texts, and calls.

If I hadn't changed the Settings as much, I know the Sense would definitely not have been able to last three days. But in addition to the Versa 3, it's the first of Fitbit's smartwatches to come with fast charging capabilities. So, you can charge it up to 80 percent in 40 minutes. Thankfully, if you're in a rush and need to use it for a workout, you'll get up to one day of battery life in only 12 minutes.

Regardless, it would've been nice if Fitbit packed a bigger battery into this one knowing exactly how many sensors and features are working simultaneously around the clock.

You might want to wait to drop money on this one

The Fitbit Sense certainly packs plenty of features that justify its over $300-plus price tag. But unlike the company's other devices, it's not for the ultimate fitness buff who only wants to focus on exercise metrics. Instead, it's a well-rounded smartwatch that fills the gap for those who need a smartwatch that focuses on wellness as much as it does fitness.

But there are minor annoyances that hinder it from claiming the title of the ultimate smartwatch: the unpredictable heart rate monitor, the mediocre battery life, and the somewhat useless stress management score. Plus, with a list of features like ECG readings, audible replies, and Google Assistant capabilities all slated to come later in 2020, the Sense just feels half-baked at launch.

If you're the looking for a smartwatch in the Fitbit ecosystem that's more streamlined when it comes to fitness metrics, then you're better off sticking with the Versa lineup. Otherwise, the Charge 4 is also an excellent choice.

The Fitbit Sense, on the other hand, is enjoyable to use but tough to recommend for everyone. With its emphasis on mindfulness when tracking stress, the Sense is more ideal for those who are in the market for a device that will help fuel their meditation practice or integrate it into their fitness routines.

But if you want the full experience, you're better off waiting until Fitbit makes all the updates to the Sense as promised.