I just did a 20 minute FTP-test (resulted in 295W) and was checking my power- and heart rate details on intervals.icu. Apparently, my threshold heart rate was calculated as 176 bpm, resulting in below scheme following the Friel method:
Whilst I can relate to the upper zones, i’m having some trouble interpreting the zone 2 power and heart rates i.e. 56-75% of power and/or 81-89% of threshold heart rate. Nowadays, when I do an endurance ride and keep the average power around 190 (for average heart rate of 135-140), I feel tired afterwards.
If, let’s say, i should train in the upper half of zone 2, then my power constantly needs to be around 210-220 W (heart rate app. 155). I know I can hold this for 1.5 hour, but i also know this will be quite taxing on my body, let alone that I ride 5 hours in that zone. Even the lower range of this zone seems very high. In the end, it seems that it won’t feel like an endurance ride because of the too high pace.
Is this a matter of training? Should I be building up in the endurance zone: not only in time, but also in percentage of power output? Or is this something that i’ll get used too by just going by my power numbers?