Hello everyone, I have a question on how to interpret the results from my indoor and outdoor sessions:
Top is a ~60km indoor race on Zwift w/ Wahoo Kickr Core as the power meter
Bottom is an outdoor session with Wahoo Elemnt Bolt 3 computer and SRAM XX SL crank power meter.
To me both these sessions were equally as difficult as they were near max. However, I notice two key differences I can’t explain:
Even though I stand up on the climbs in both, the power of the indoor is nowhere near the power of the outdoor on climbs.
Why does the purple line, ‘MPA I believe, not move for the analysis of the indoor session?
I’m ok with the answer that the Wahoo Kickr Core isn’t as accurate, fast, etc to read max power as the crank power meter. The issue I have is the training difficulty is viewed differently by Xert, correct?
As they are both (near) max efforts, at least one of the power meters is incorrect, the top one you barely exceeded TP and most of the ride looks like tempo or endurance pace impossible to say which power meters is closer to accurate from the charts alone. You could do some real world test (eg an outdoor hill climb with low enough speed that air resistance isn’t a significant factor - you can use a climb speed from power calculator and compare vs what you observe).
Would first make sure they are both calibrated (Kickr after a warm up), you have the right crank length set for the crank PM etc
You won’t be able to really use your outdoor signature for indoor rides unless you resolve. If you try a Xert workout with the outdoor signature indoors, it will be much too hard. And your TL, allocation between peak, high low strain will not be meaningful.
Easiest resolution if possible is to use the same power meter indoors and outdoors - not sure if that is an option here. If so, you can set it so that power is taken from cranks and still use ERG mode / trainer control with the Kickr. But either way I’d calibrate each one
Thank you, I can absolutely use the SRAM cranks for both as it is the same bike. I’ll look into calibrating the SRAM cranks and then choose that as the power source in Zwift and see how that goes.
And YES, I’ve noticed the XERT training sessions are way too hard when I run them indoors.
If you’d like to compare the two power meters ride an indoor HIT workout with trainer power connected to your head unit and crank power connected to EBC or vice versa.
Save both recordings then upload the FIT files to a comparison tool.
