Data Recording Settings
Select 
> System > Data Recording.
Cadence Averaging: Controls whether the device includes zero values for cadence data that occur when you are not pedaling (Data Averaging for Cadence or Power).
Power Averaging: Controls whether the device includes zero values for power data that occur when you are not pedaling (Data Averaging for Cadence or Power).
Log HRV: Sets the device to record your heart rate variability during an activity.
5Hz GPS: Sets the device to record high frequency data during downhill runs (5Hz Data Recording).
The Edge 850 can record data at 5Hz, allowing you to analyze your position during downhill descents, known as runs, with more accuracy.
If enabled, the device records data at 5Hz during the downhill and descending runs for the Enduro MTB and Downhill MTB activity profiles (Biking Activity Profiles). The Edge bike computer displays a 5Hz indicator on the ride timer during a run, and on the ride summary.
The bike computer does not record data at 5Hz while in battery saver mode.
After you complete and save a ride, you can view a detailed analysis of 5Hz descent data on your Garmin Connect account (Garmin Connect).