FORERUNNER 245 - HRB update too slow during activity

Hi,

I created a custom activity which contains some HRB fields. During a crossfit session I noticed that the HEART RATE field is updated with a delay.

For example, if I have a heart beat of 80 before 15 push ups it will be 85 after the push ups. 20 seconds later the heart beat shows a value of 115.

I feel that my heart beat is higher after the push ups so the 85 value is certainly not correct!

Is there a setting which is related to this behavior?

The Garmin page https://www.garmin.com/en-US/legal/atdisclaimer is saying the following:

Accuracy of Wrist-based Heart Rate (Elevate)

The frequency at which heart rate is measured varies, and may depend on the level of activity of the user. When you start an activity with your Garmin optical HR device, the optical HR monitor measures more frequently. The intent is to provide the user with a more frequent and accurate heart rate reading during a given activity.

Could it be that a custom activity is measuring less frequently then other activity types? Does a table exist showing which activity types have which measure frequency?

Thanks for any feedback!

Kr;