7
Measuring your heart rate
When your heart beats, your capillaries expand and contract based on blood volume changes. PurePulse™
LED lights on your Fitbit Model FB407 reflect onto the skin to detect blood volume changes, and finely-
tuned algorithms are applied to measure heart rate automatically and continuously.
Default heart rate zones
Heart rate zones can help you optimize your workout by targeting different training intensities. Your
zones are calculated based on a percentage of your estimated maximum heart rate. Fitbit calculates your
maximum heart rate with the common formula of 220 minus your age.
To quickly determine what zone you’re in, take a look at the heart icon:
Out of zone Fat burn Cardio Peak
•
When you’re out of zone, which means you’re below 50% of your maximum heart rate, your
heart rate may be elevated but not enough to be considered exercise.
•
Fat Burn zone, which means your heart rate is between 50% and 69% of your maximum, is the
low-to-medium intensity exercise zone and may be a good place to start for those new to exercise.
It’s called the Fat Burn zone because a higher percentage of calories are burned from fat, but the
total calorie burn rate is lower.
•
Cardio zone, which means your heart rate is between 70% and 84% of your maximum, is the
medium-to-high intensity exercise zone. In this zone you’re pushing yourself but not straining.
For most people this is the exercise zone to target.
•
Peak zone, which means your heart rate is 85% of your maximum or higher, is the high-intensity
exercise zone. Peak zone is for short intense sessions that improve performance and speed.
At any time you can check your dashboard to see the amount of time you’ve spent in each zone.
Custom heart rate zones
Instead of using the default heart rate zones you can configure a custom zone. When your heart rate is
above or below your custom zone you’ll see an outline of a heart, and when your heart rate is in your
custom zone you’ll see a solid heart.
To set a custom heart rate zone using the fitbit.com dashboard:
1.
Log in to fitbit.com.
2.
Click the
gear icon
in the top-right corner of the dashboard and select
Settings
.
3.
Using the navigation tabs on the left, find
Personal Info
.
