Why are the active zone mins showing so low? Inspire 3

[nms1]

 

Please can someone help me understand this? This was a 40 min workout, during which my heart rate was above 100 for the majority of time and above 120 most of the time. I am 50+ years old. Why are the active zone mins showing so low? 

Moderator Edit: Clarified subject

[LZeeW]

@nms1   Active Zone minutes use an equation that uses both your age and resting heart rate.  They are calculated very different from active minutes.  You can check your personalized heart rate zones by tapping on the zone minute icon on your mobile app.

This article has more information: How do I track my heart rate with my Fitbit device?  It's important to understand that the active zone minute heart rate zones are very different from active minute zones.  For example, my fat burn zone starts at 76 bpm using active minutes, but 91 using active zone minutes.

[nms1]

I'm still not clear.

My fat burn zone starts at 83bpm

My cardio zone starts at 116bpm

For the workout above I was exercising for 40 mins and, as far as I saw, my heart rate never went below 89bpm and for the majority of the time it was over 110bpm

[LZeeW]

@nms1   Those values are the heart rate zones for active minutes for a 54 year old.  Like I wrote in my previous post, a different equation is used to calculate active zone minutes (AZM).  You need to tap on your zone minute icon to see your active zone minute heart rate zones.  These are mine (BTW, I'm 67 years old):

My fat burn is lower than what I listed in my previous post.  Active zone minutes use your resting heart rate in the equation.  My RHR is lower today.

The CDC and WHO changed their activity recommendations four years ago.  They now both recommend a minimum 150 minutes per week of moderate activity (AZM fat burn) or 75 minutes of vigorous activity (AZM cardio) or a combination that gives you a weekly minimum of 150 AZM/wk.  The CDC updated their target heart rate zones for moderate and vigorous activity.  CDC Target Heart Rate  The CDC equation doesn't use RHR in its equation.

I hope this helps.