User manual
Table Of Contents
- Getting Started
- Set up Fitbit Charge 3
- Wear Charge 3
- Change the wristband
- Basics
- Notifications
- Timekeeping
- Activity and Sleep
- Fitness and Exercise
- Weather
- Restart, Erase, and Update
- Troubleshooting
- General Info and Specifications
- Regulatory & Safety Notices
4. Charge 3 gently vibrates and the screen flashes when you reach your goal.
Check your heart rate
Heart-rate zones help you target the training intensity of your choice. Charge 3
shows your current zone and progress toward your maximum heart rate next to
your heart-rate reading. In the Fitbit app, you can see your time spent in zones
during a particular day or exercise. Three zones based on American Heart
Association recommendations are available by default, or you can create a custom
zone if you have a specific heart rate you're targeting.
Default heart-rate zones
Default heart-rate zones are calculated using your estimated maximum heart rate.
Fitbit calculates your maximum heart rate with the common formula of 220 minus
your age.
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