I have been using a Fitbit since they came out with the Flex 2 and my latest being the Fitbit Alta HR. As such, when presented with the opportunity to try out the latest Fitbit Charge 4, yours truly was very excited to do so and accepted it willingly, although I did wonder how I could test out all the new features while in lockdown mode. Nonetheless, I’m sure that there will still be some valuable insights to share!
What’s new
Built-in GPS
The Fitbit Charge 4 is the company’s first tracker with in-built GPS to provide real-time information on pace and distance on runs, walks, hikes and bike rides. There are seven GPS-enabled modes to choose from, including a new Outdoor Workout mode, which right now may look like hiking, running or brisk walk. But once the lockdown is over, other activities include surfing, kayaking and even downhill and cross-country skiing.
I did not try out this feature because I’ve relegated myself to home exercises and walking up and down the stairs within my block of flats ever since the circuit breaker period begun. What did get me noticing was that my Fitbit Charge 4 quite accurately tracked the number of flights of stairs I climbed and therefore, adjusted the estimated calorie output accordingly.
Workout intensity map
Fitbit has improved its workout intensity map and through the app, you can now see a detailed breakdown of your different heart rate zones during your workout. After completing a GPS-enabled workout, you can sync your device to see a GPS-powered heat map in the app to help you visualise and improve your activity against different terrains. Definitely a useful feature for those who enjoy running or trekking outdoors.
Active Zone Minutes™
Charge 4 is the first Fitbit device with this new metric that is calculated using your age and resting heart rate to provide you with a more personalised measurement of how hard you worked during any activity. Personally, I love this new feature the most! As mentioned, during this lockdown period, I have been faithfully exercising at home and my pre-Charge 4 routine was alternating days of yoga and strength training, with a few instances of trying out Tabata workouts.
Through the Active Zone Minute’s insights, I now get real-time alerts on my wrist each time I change from cardio to fat burn zone and this has made me more mindful about my workouts. It no longer was an “I don’t think I worked out hard enough” but an actual fact as I could immediately see that I was not entering into the peak zones, thus ensuring that I pushed myself harder and chose better workouts for the rest of the week to ensure that my exercise goals were met with efficient exercise routines. As a result, I’ve been mixing in aerobics to hit both the fat burn zone and total zone minute goals. In addition, I could also tell which particular exercise was increasing my heart rate and that made me more encouraged to continue mixing that exercise into my regime.
Do note that everyone’s Active Zone Minute goal is 150 minutes per week by default, based on guidelines from the American Heart Associations and the World Health Organization. However, more experienced athletes will want to increase that goal.
Sleep tools
The sleep score is available for any Fitbit device that tracks heart rate and this provides daily insight into your sleep quality based on heart rate, restlessness, time awake, and sleep stages. This can be viewed in the Fitbit app or directly on the Fitbit Charge 4’s on-screen dashboard by simply swiping up. Premium members will get a deeper analysis of their score with guidance on how to improve their overall sleep quality in the app.
One insight that I particularly liked was the percentage of your sleep within the four stages – awake, REM, light, and deep. You can compare that with the benchmark ranges of those of your age and sex. So if you’re not getting enough quality sleep, you might want to take up on some of their tips on how to get some better shut-eye or check out some of the relaxing sounds or stories and meditations for sleep in the mindfulness section of the Discover tab. But you can also read some tips on getting better sleep here.
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Sleep insight from Fitbit | Sleep insight from sleep app |
I compared Fitbit’s score with a sleep cycle app that I’ve been using for years and I’m quite intrigued at how similar the results are in terms of times the sleep stages and variations of my breathing during sleep (i.e. did I snore?). My sleep app does that through the sounds made while I sleep whereas the Charge 4 estimates oxygen variation through a combination of the red and infrared sensors on the back of the device to indicated breathing variations (I call this the snore score), as well as through the heart rate. What I would’ve liked to see in the Fitbit app is whether there’s any correlation between my sleep and my exercise or even diet or menstrual cycle. After all, Fitbit has added the menstrual cycle feature for us women and when it comes to overall health, all these things should be interlinked.
By the way, I don’t normally sleep for more than 7 hours a day but for that particular night, I was feeling really tired due to work plus my period.
There’s a sleep mode where you can turn off notifications and disable the screen display (yes, this can get quite annoying when you’re tossing and turning and the device suddenly lights up, further interrupting your attempt to snooze). What I’m looking forward to is the smart wake feature, where you’ll be able to set a smart wake alarm to wake you at the optimal time so that you wake up feeling recharged and ready to start the day. Alas, it’s still not ready.
The aesthetics

As wearables are an accessory that we’re seen with most of the time, we’ve got to talk about the design of the Fitbit Charge 4. I liked that the display face is relatively large but not clunky, nor does it try to look like the Apple Watch (unlike *cough* the Ionic) and you can choose from several different displays to further personalise your watch face. As for the width of the straps…now…Fitbit has tried over the years to make nicer wristbands for their devices but for someone like me who has a smaller wrist, I really do not like this thick rubber wristband and I wished that the width of the straps was a bit thinner. But I have to say that the woven and leather bands look quite nice. But if that’s the only downside…I can still live with it.
Where to get it
I do love all the new features of the Charge 4 and I am reluctant to return it once this review is over. You can order the Charge 4 and Charge 4 Special Edition at Fitbit.com or at major retail stores in Singapore such as Best Denki, Challenger, Courts, E-Gadget, Gain City and Harvey Norman at S$248 and S$278 respectively.
Images: Fitbit and Melissa Fann
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