It always produced an accurate mileage count and map on the app afterward. I started up the Charge 4 every time I took my kids and dog out for a ( socially distanced) hike in the park behind my house, and I had no noticeable delay connecting to GPS.

For the past week and a half, the Charge 4 has accurately recorded how little sleep I’ve gotten and I haven’t been able to fool it, even on nights when I popped awake at 4 am, checked my watch, and spent hours lying there thinking about the fate of the world.īut it’s perfect for long, idle, outdoor days, like when golfing or hiking with friends (did I mention there's a new 'Outdoor Workout' category for tracking these kinds of activities?). Anything under 60 is extremely poor and scores over 80 are good. The new SpO2 sensor also measures the changes in your blood oxygen levels, and Fitbit uses a proprietary algorithm to calculate these factors into an overarching Sleep Score. The Charge 4 uses a three-axis accelerometer and the optical heart rate sensor to measure your time asleep and the amount of time you spend in different sleep stages. On the plus side, Premium is still a deal if you were planning on enrolling in a separate coaching or training program anyway. It does stink a little that Fitbit hides so many of its best software features, like the advanced sleep software, guided programs, and personalized insights, in the Premium subscription.

Its sleep features are the best in the market, and one of the reasons why you should probably spring for a Fitbit Premium membership, which costs $10 per month or $80 per year. Longer battery life means you can wear the watch while you’re sleeping, another arena where Fitbit excels. It's a relief to cut one device from my nightly routine of plugging in my phone, laptop, and kid's iPod. When tracking one to two activities per day, with notifications turned on and at normal brightness, the Charge 4 lasts me between 5 to 7 days. It is so, so nice to not have to charge it every night like I have to do with my Apple Watch. To me, the primary reason to get a Fitbit is battery life.

Charge 4 fitbit