Fitbit Sense 2 review: I’m really stressed, apparently, and this smartwatch wants me to think about it
With the second-generation device, the company wants you to feel mindful about your body at all times
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“Fitbit is doomed.” That’s what critics said when Google announced it was acquiring the fitness wearable company in 2019. Some feared Fitbit would lose its identity, as it was inevitably rolled into future Google wearables, while others worried Google’s influence on the device might be too severe. But nearly two years on from the completion of the acquisition, and with the company’s new flagship Fitbit Sense 2 device on our wrist, it seems there wasn’t too much to worry about. Fitbit still has a place in the increasingly crowded wearables market, even with Google on board.
From what we can see, Google’s influence on the latest Sense has been kept to a minimum, if not dramatically reduced. While the company has been busy weaving Fitbit into the fabric of its new Pixel Watch (poaching essential Fitbit sensors), on the Sense 2, you’re still getting a simple, non-intrusive Fitbit experience like no other.
Sure, the fitness tracker does feel more like a Wear OS product, following a redesign of the user interface, but the Fitbit Sense 2 still runs on Fitbit OS, and you can still use Fitbit Pay to make NFC payments, with Google Wallet said to be launching in a future update, as well as Google Maps.
There are things missing, however, and these omissions might put you off buying the device. The voice assistant is weirdly locked to Alexa, and there is no support for Google Assistant, despite both being available on the original Sense. On top of that, third-party apps have been seemingly stripped from the watch altogether, you can’t control music playback, and wifi has been deactivated.
However, it’s also £30 cheaper than the original model, and is flush with class-leading health, sleep and stress-tracking features. These are so class-leading, we knew exactly when our emotions were heightened throughout the day, because the Sense 2 kept telling us. And, blimey, we were stressed, and we were forced to be mindful about it.
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How we tested
Wearables are growing in sophistication as each generation develops. They don’t just track your runs or workouts anymore. While we did test the basics, assessing its ability to keep track of our CrossFit drills and (admittedly slow) jogs, battery life and durability, the Sense 2 is, like the original fitness tracker, a device that encourages you to be more mindful, understand when you’re feeling stressed and track how well you sleep.
While it’s filled with sensors for tracking all kinds of things, it offers guided meditation, mindfulness sessions and more. We’ve tested all those features, on particularly stressful days and days when we were feeling calm. So, did it help us understand how our body ticks?
Fitbit Sense 2: £269.99, Fitbit.com
- Battery life: Up to six days, with fast-charging
- Voice assistant: Alexa
- Sensors: ECG sensor, heart-rate sensor, continuous EDA sensor, SpO2 tracker, skin-temperature sensor, ambient-light sensor, 3-axis accelerometer
- Features: Built-in GPS, all-day body response tracking and notifications, sleep-stages tracking, guided mindfulness and breathing sessions, Bluetooth calls
- Pros: Stress tracking is incredible, unrivalled battery life, good range of workouts, easy to use
- Cons: No music playback, GPS isn’t massively reliable
- Rating: 4.5/5
Design
Put the Sense and the Sense 2 side by side and you’ll barely be able to tell them apart. The Sense 2 is lighter by a few grams and thinner by a millimetre or so. That millimetre having been shaved off means it juts out less awkwardly on your wrist, sitting much more uniformly against your skin, and we barely remembered we were wearing it, because it’s so feather-light. Design-wise, though, both devices are practically the same.
It still features the same compact 40mm rounded aluminium square case, the same 1.58in AMOLED display with a 336 x 336 resolution, and the same soft silicone straps in medium and large (both come in the box as standard). Those too are as comfortable as ever. We were able to adjust the straps to a tight enough level that the Fitbit was in constant contact with our skin – assuming a tighter fit meant a better continuous electrodermal activity (cEDA) reading (more on that in a bit).
Even though it’s largely the same in terms of its handsome design, what is different is the introduction of a physical button on the side. The original Sense featured a haptic groove instead of a physical button, which frustrated users. Many complained it either didn’t work when it was pressed, or was being activated accidentally. There’s no chance of either of those things happening now that Fitbit has implemented a physical button. It’s easy to click and hold, stretches almost the length of the watch, and doesn’t protrude too far.
Like the original Fitbit Sense, the second-generation model features an always-on display, but it isn’t turned on by default – a good thing, because it basically halves the battery life of the smartwatch. Flipping your wrist towards you or pressing the button reveals the watch face. It’s a little less convenient, and sometimes the screen is a tad slow to respond when you turn your wrist, but it preserves battery massively.
The user interface has also been given a makeover. As mentioned above, using it feels more like we’re using a Wear OS device than one running Fitbit OS. It’s wonderfully simple to use – you switch from tiles by swiping left and right, access the quick settings by swiping down from the top and view notifications by swiping up. We also loved that we were able to quickly start our last-used workout, so we wouldn’t have to cycle through the list and find the right one.
Because the Sense 2 now has a physical button, it’s easier to hold down the side button and activate Alexa, navigate quickly to our shortcuts, and view all our apps in one list too.
Features
The Fitbit Sense 2 is one of the smartest fitness trackers on the market. As with the original Fitbit Sense, the device is able to track a whole host of body markers. It told us when we’d worked out enough to reach the recommended weekly active zone minutes, tracked our quality of sleep automatically to tell us how long we’d been in deep and REM sleep, and asked us to get up and take 250 steps every hour, as well as track our SpO2, ECG, heart rate and skin temperature. The skin-temperature sensor isn’t technically a new sensor, but smartwatches such as the Apple Watch are only now adding this one into the mix.
The Sense 2 then used all that data to give us a daily readiness score, telling us if our body was ready for another session at the gym, if we needed to rest, or if it was a day to go all out and hit a new personal best. It accurately tracked our CrossFit sessions too, giving us information at a glance.
What continues to set the Fitbit Sense series apart from the competition, however, is its focus on mindfulness. Just like the first Sense, the Sense 2 can monitor your stress levels. The Fitbit Sense is also able to track electrodermal activity, used to detect tiny electrical changes on the skin, to tell us when we were stressed or our emotions were heightened. Data points include our heart rate, heart-rate variability and the temperature of our skin.
Fitbit’s taken this one step further in the Sense 2, adding in a continuous EDA body response sensor, so now it’s always looking for signs of stress. The EDA sensor on the first Fitbit Sense was a little less useful because you’d have to tap into an app and place your palm on the screen for two minutes to get a reading – which you can still do on the Sense 2. It was more of a mindfulness exercise, with the smartwatch tracking your electrodermal activity as you listened to one of Fitbit’s mindfulness sessions. But the cEDA sensor is actually much more useful – it’s always searching for signs of stress. For a week, it buzzed incessantly as we constantly worried about spiralling mortgage rates, energy bills and the cost-of-living crisis.
When the Fitbit Sense 2 noted an abnormal body response, we got a notification on our device asking us to record how we were feeling at that very moment – whether that’s excited, sad, stressed or one of the other prompts. It can’t pinpoint which emotion you’re feeling, just that your heart rate might be elevated and that you’re sweating a little bit. It needs your own human input.
It’s something that David Ellis, a computational scientist and associate professor of management at the University of Bath, confirmed. “In laboratory studies, EDA sensors are often used to measure arousal as well as stress because, as you can imagine, there’s an overlap,” he explains. “If someone’s galvanic skin response increases, that could be because they’re stressed, but it could also be because they’re just excited about something or engaged in something.”
That’s not ideal, because it assumes people have good insights about their body and how they’re feeling – sometimes we don’t know whether we’re feeling calm or happy, sad or stressed. And if Denholm from the IT Crowd has taught us anything, it’s that being told you’re stressed all the time (even if the Fitbit is just asking you for a body response) can heighten your levels of stress.
The body response feature also isn’t instantaneous. There were times when we knew we were feeling stressed, but the smartwatch didn’t give us a body response alert until half an hour had passed – it would’ve been useful to get a mindfulness prompt so we could have caught it in the moment. Still, once we did catch our stress levels rising and accessed one of the quick mindfulness sessions, we always felt better.
But slight quibbles about implementation aside, was it accurate? Miraculously so. The Fitbit Sense 2 was incredibly precise at detecting when we were stressed. Looking at historical trends in the Fitbit app, the days when the Fitbit detected more body responses were the days when we knew we were feeling particularly anxious. It could go one step further, however.
If the device could monitor what prompts we’d fed it over time, learning how we were feeling based on our cEDA body response, it would make the Fitbit Sense 2 even more useful, but for now, it’s more of a mindfulness exercise. When the cEDA sensor detected we might be feeling stressed, it was basically just encouraging us to take a step back and recognise we were feeling a certain way. But it wouldn’t tell us whether we were feeling excited or stressed – we had to decide that for ourselves.
While the cEDA sensor is the obvious star of the show, Fitbit also added a further 20 new exercise modes on top of the 20 on the original Fitbit Sense – including HIIT, CrossFit, rollerblading, weightlifting and dance – making it more versatile than ever. It detects when you’re working out as well, something the new Pixel Watch can’t do, despite the Fitbit integration. But it’s not all rosy, there are some things we found frustrating with the new Fitbit Sense 2 – and it’s actually because Google has taken itself away from the device, not because it wanted to stamp its mark on the product.
As mentioned above, Alexa is the only voice assistant on the Fitbit Sense 2 and it’s not set to get Google Assistant. Frankly, that’s a detriment to the device. Amazon’s voice assistant isn’t very useful. It failed to understand or compute any of our requests related to the device. It couldn’t start a workout, it couldn’t tell us the battery life of the device, it couldn’t start an ECG reading, it couldn’t really do anything besides tell us the weather or answer non-device-based questions.
The in-built GPS wasn’t very accurate either, and said we’d run a street away from where we actually were. We’re hoping this will improve when Google Maps comes on board, but there’s no timeline for when that will happen just yet. But, as of now, the GPS isn’t incredibly reliable when it comes to mapping your runs.
There aren’t any third-party apps on the device either, they’ve been stripped completely, so we couldn’t even get MyFitnessPal on the watch, to track our meals, which is something you were able to do with the original fitness tracker. Wifi has also been deactivated, so you can only update the smartwatch via Bluetooth 5 when it’s connected to your phone. And, finally, one of the worst changes? The removal of music playback – you can’t control your music or podcasts while on runs anymore, and you can’t upload music to the device either for offline playback. It’s a crucial feature that all smartwatches have, including the first Fitbit Sense.
It does make the smartwatch feel a little more like a standalone stress-tracker, rather than a smartwatch. But there’s another thing you’re not going to get if you opt for the Pixel Watch over the Fitbit Sense 2: incredible battery life.
Battery life
The one thing that has always stopped us from sticking with smartwatches after we’ve finished reviewing them is that they require constant charging. We’re charging them so often that we forget to put the smartwatch back on, at which point it becomes useless. We don’t have this problem with the Fitbit Sense 2, because its battery life is absolutely bonkers. You get up to six days of battery life on a single charge with the always-on display turned off, and we sometimes even got more than that, depending on our level of activity.
It fast-charges too, so you can pop it on the magnetic charger and get it juiced up in an hour or so. Being able to wear a device and not think about charging it puts the Sense 2 leaps and bounds ahead of some Wear OS devices, which can only clock in one day’s worth of battery before needing a recharge. And even though it feels like the Sense 2 is more of a fitness tracker using Fitbit OS, it benefits the Sense 2 massively in the battery life department.
The verdict: Fitbit Sense 2
So, is the Fitbit Sense 2 just a glorified stress tracker, and should you get the cheaper Fitbit Versa 4 or the Pixel Watch or maybe even the older Fitbit Sense instead? While the Fitbit Sense 2 has stripped a few things that make the original Sense (in some ways) better, including third-party apps and Google Assistant, the original model is actually more expensive, and doesn’t feature that cEDA sensor or the 20 new fitness modes. At launch, the original Fitbit Sense cost £299.99, while the Sense 2 is actually £30 cheaper, costing £269.99.
The Fitbit Versa 4 might be cheaper, but it doesn’t have a dedicated skin temperature sensor, an EDA sensor for stress-tracking and there’s no ECG. The Sense 2 remains the stress and wellness device, while the Versa 4 continues to be the general fitness device. And the Pixel Watch? If you want something that acts and looks more like a smartwatch, with some Fitbit elements built in, it might be a better, albeit more expensive, proposition. But remember, it won’t last six days, and it won’t track your workouts automatically like the Fitbit range.
The Fitbit acquisition has seen the Fitbit Sense 2 become more streamlined in its approach, but we still enjoyed the very lengthy battery life, and the stress-tracking features – while occasionally aggressive – really did help us feel more mindful about how we were feeling. Maybe in the next iteration, it’ll be able to learn how we’re feeling and tell us instead, so we know how to deal with it.
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