Each activity recorded by FR945 is assigned Aerobic and Anaerobic Training Effect and categorized in Training Load Focus categories (Base, High Aerobic, Anaerobic). This works well for short intense sessions or long low intensity sessions each categorized properly.
If however you do say 2x20m @ Threshold followed by or inside longer endurance ride whole activity (all Training Load units) are added into High Aerobic category. Where in fact only 40 or so minutes were spent in High Aerobic zone and the rest was in Base category. This produces skew metric for 4 week Training Load.
This affects any combination of high and low intensity mix in a single session. For example: couple sets of HIIT 40/20 intervals or VO2 intervals within longer ride will add all Training Load to either High Aerobic or Base category based on overall proportion of HIIT and Endurance part of the session. If implemented correctly, HIIT minutes and TL should be added to High intensity category and time, TL spent in Endurance zone separately added to Base category.
Only workaround to this is separate the workout into more activities and record intensity intervals as one activity and endurance part as another activity. Which is kind of stupid and "smart" watches should figure this out themselves!
