The first thing that you need to know is that HRV analysis is only relevant if done on a rest or during a sleep record. In fact, based on the literature, HRV values can only be accurately and meaningfully measured during a period with very minimal activity and movement. Indeed, it was reported that activity and movement can cause outliers in the ECG signal and then bias the HRV calculation and interpretation (please refer to the attached document Hexoskin-MeasureHRV).
If you still want to perform HRV analysis during an activity or a wake period, you will need to download your data under Binary format and do your analysis by eliminating the outliers in the ECG signal. The HRV analysis can be performed with Kubios software (for more details, please refer to this link).
To do this, you need to:
1. Download Kubios software (free version)
2. Download the HxConvertSourceFile software*
3. Download the data of your choice
4. Make sure that you check the following boxes when you download and convert your CSV data:
5. Open Kubios software
6. Click File, then Open and then choose the file "RR_interval.txt" of your choosing
7. For the data analysis and interpretation, please refer to the Kubios User's Guide.
Finally, as your HRV analysis is being performed on an "active" period, we strongly recommend only using the HRV metrics calculated by the time-domain analysis as they are the least sensitive to changes in the activity intensity.
For more information regarding measuring your HRV with Hexoskin, take a look at this PDF file:
Measuring your HRV with Hexoskin