Charge 6 heart rate doesn't register well when exercising

[Sreichs]

Anytime I start an exercise, it takes about 15 minutes for it to actually register a moderate or cardio heart rate. By then I'm usually doing a bit of a cool down for a couple minutes before ramping up again. My heart rate then drops to about 95, I turn the tension up and start going again and 10 seconds in heart rate drops to 67 or 70 again for another 15 minutes no matter how fast my heart is pounding. Every now and then, it works normal after the first 15 minutes but 90% of the time it's just showing a resting heart rate. Now it doesn't do this throughout the day. I have an active job and often times my heart rate will be 120 BPM with what I'm working on and so forth, it always picks up those increases no problem. Never seen an flaw in just normal function. Only anytime I engage an exercise. Now this is frustrating as I use my heart rate as a guide to know how hard to push myself. Now I know these sensors aren't perfect and a strap would be most effective I just don't understand why it registers my increases in heart rate throughout the day but not when I'm actually purposely elevating my heart rate.

Moderator Edit: Clarified subject

[Julia_G]

Hi, @Sreichs , this can happen sometimes due to sweat on your wrist when exercising or because the exercise you are doing involves wrist flexion (for example rowing machine or some weight exercises).  During exercise Fitbit recommends wearing your tracker a little tighter than usual and higher on your wrist.  That can help with this issue.  I suggest trying that and let us know if you get any improvement.

[Mnmadeira]

It happens to me as well.

Usually, I jump on my bike and start exercising, and I reach the point where a conversation is impossible. 

But not for the HR 6: the display shows I'm resting.

Sometimes, when I pause and restart, it shows an increase. 

It's the same thing when walking.

And I'm sure it's not the position in my wrist or sweat.

Last night, it stopped tracking my sleep at 2 AM.

I have had HR since version 3, and this one is the worst so far.

I'm waiting for the one-year mark when they break the connection with the band or the screen gets too dim, then replace it with a Garmin.

[Sreichs]

I have tried wearing it tighter multiple times with no luck and have taken it off and dried wrist and watch multiple times as well (with no luck and I and watch are also usually dry as when I start my exercise I'm not sweating yet). I'll maybe try moving my arms more especially at the start. It's just weird that when I'm walking around getting water and such and I hop on the bike and start peddling it will show 102 (or whatever) BPM and as soon as I start the exercise, within 5 seconds it then shows 70. 

[Sreichs]

I'll try the pause and restart 👍 I've never had the issue where it stops tracking in while asleep so that's good as that definitely sucks. Hopefully you get better luck when you switch! 

[Julia_G]

Hi, @Sreichs , in my reply I was assuming you started the exercise app on your Charge 6 and are not relying on automatically detected exercises?  You will get a more accurate heart rate reading using the exercise app.

[RiekoC]

To add to @Julia_G response

If you are using auto detect for your exercise, you can adjust the time when your Charge 6 starts tracking the activity. The default is 15+ minutes. You can change it to 10+ minutes, which is the lowest amount of time available for this feature.

To change the auto detect time:

• Tap on the Exercise Days tile on the Today page in the Fitbit app
• Tap on the 3 vertical dots in the upper right of the Exercise page and select Activity settings
• Under Auto Recognized Exercises, tap on the exercise that you want to change the time for. Enter the time and tap Save in the upper right
• You can also turn off Auto Recognize for any exercise that you don't do by tapping on the activity, disabling Auto-recognize, and tapping Save in the upper right. These activities will show as "Ignored"

[Sreichs]

I don't use auto detect for main workouts (spinning, hiking, workout vids etc). Sometime at my job it aut detects cuz I have a physical job but workouts, no, I activate an exercise on my watch. 

[Sreichs]

I don't use auto detect, I activate on my watch. Altho I'm tempted to use auto detect as my heart rate is usually accurate on the watch when no exercise is happening so it may be the way to go. It probably won't guess spinning tho as I'm not moving so 🤷