Charge 6 - How accurate are active minutes

[aidenso]

How accurate are active minutes? Lately when I’ve been working out, running as hard and fast as I can, sweating and breathing heavy, my heart rate sits around. I’ve tried different tightness and positions on my wrist but it doesn’t change. Is it a problem with my Fitbit or am I just not getting the workout I feel like I’m getting?

Moderator edit:  updated subject for clarity

[JuanFitbit]

@aidenso , A warm welcome to the Community! Thank you for your message. 

Active Zone Minutes are earnt for time spent in the fat burn, cardio, or peak heart-rate zones. To help you maximize your time, you earn 2 Active Zone Minutes for each minute you’re in the cardio or peak zones. Heart-rate zones are personalized based on your fitness level and age.

Heart-Rate Zone	Active Zone Minutes
1 minute in the fat burn zone	1 Active Zone Minute
1 minute in the cardio or peak zone	2 Active Zone Minutes*

Do you see your heart rate on your Charge 6?
Are the green LEDs blinking?
Is the heart rate measurements transfered to the app after syncing?

More about the active zone minutes can be read here: What are Active Zone Minutes or active minutes on my Fitbit device?