david
3 July 2025 15:12
4
You can easily create custom activity streams to pickup those fields. Have a look at the record fields for the fit file for an activity (“Original Fit File” on the activity data tab) on fitfileviewer.com :
It says “mps” in the units but those values look like mps * 1000.
Intervals.icu now supports custom activity streams for extracting data from record messages in fit files. Click “Charts” under the activity timeline chart and then “Custom Streams”.
[Screenshot 2023-07-19 at 21.16.30]
[Screenshot 2023-07-19 at 21.17.04]
Click “Add Stream” to create a new stream or search for streams created and shared by other athletes. Note that these streams are per athlete. You can add your own streams to athletes you coach using the search button.
[Screenshot 2023-07-…
You will probably need to use some Javascript to convert to actual mps:
Custom activity streams now support computing streams from fit file messages (not just record messages) using Javascript. Note that this cannot be used with the simpler “Record Field” streams but the process for creating the stream is the same:
Tick the “Processes fit file messages” box and create a script instead of entering a record field name.
[Screenshot 2023-08-11 at 07.21.32]
This script just grabs the heart_rate data from the record messages:
{
for (let m of icu.fit.record) {
…
