Fitbit Exercise graphs

[Ukase]

What does "Peak" mean, in reference to fat burn, cardio and Peak on the graph? 

[USAF-Larry]

@Ukase, you will probably find the answers in the help article, What should I know about my heart rate data?

Peak zone

Peak zone, which means your heart rate is greater than 85% of maximum, is the high-intensity exercise zone. The peak zone is for short intense sessions that improve performance and speed.

 

Cardio zone

Cardio zone, which means your heart rate is 70 to 84% of 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.

 

Fat Burn zone

Fat burn zone, which means your heart rate is 50 to 69% of 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.