I recently installed some power meter pedals (Garmin Rally) on my bike for outdoor riding, having previously only had power data from my Wahoo Kickr indoor trainer. Until now, outdoor rides have been using Heart Rate data for calculating XSS etc.
However, after installing my pedals (I have calibrated them, running latest firmware version), I’ve seen a significant jump in my Threshold Power, going from 203 watts to 318 watts after breakthroughs on both of my outdoor rides since installing the power meters.
As I’m beginning to ramp up my training again, my concern is that this has skewed my fitness signature to the point where the difficulty of my next indoor workouts are going to be affected compared to previous workouts. Below are the analysis for both recent free rides that triggered a breakthrough:
12/06/2025 (gap in power reading was a short rest after a climb to re-fuel/take in the view, followed by a technical gravel descent)
Is this increase in Threshold Power something to be concerned with, or is this expected due to having more power data available and is more representative of my actual capabilities?
Check that your trainer and power meter give the same power readings. Do a workout in ERG at different power targets where you log both the power readings from the trainer and the pedals. After the ride, compare how close they are. You might have to log the power using two different devices.
Which trainer do you have?
Also, make sure you have set the correct crank length. This will have a direct impact on the power values.
Thanks, I’ll give this a go over the weekend. I can drop the bike I use outdoors on the trainer to have both the Wahoo Kickr Core trainer and Garmin Rally pedals record power. I’m assuming I’ll need to have something like Zwift and the EBC app running simultaneously here with each linked to a different device for power?
The crank length is set correctly on my Wahoo bike computer, and is where I did the calibration.
Any Xert workouts that you recommend? Or will any work so long as I hit at least a few different power targets for a sustained period? e.g. a mix of Z2 and sweet spot intervals for 1-1.5 hours?
You can create an over/under workout to test your updated sig.
You’ll know within minutes if LT1 and LT2 feel off.
Click here to open Save Yourself - 90 in Workout Designer.
Edit set #3 and change 90/110% LTP to 90/100% TP (under then @TP rather than over).
Edit set #4 and change 90/110% LTP to TP.
Or enter whatever % LTP/TP you’d like to test during sets.
Click Copy at bottom, change Title to whatever you want, then Save.
The result will look like this –
Same thing happened to me a year ago when I got Assioma pedals. I figured they must be reading high. Put them on the bike on my Elite Direto trainer and they matched very closely. I discovered that I just put out more power riding outdoors. I have to admit I really don’t enjoy riding an indoor trainer so that may be part of it for me.
This can absolutely be the case if you do not have proper cooling inside. Or maybe it is easier to motivate yourself outside, especially when riding in a group.
At least I find it much easier to ride inside in the winter compared to the summer, and I believe it is due to better cooling in the winter.
It can also be interesting to establish a separate fitness signature for indoors and outdoors. Maybe the peak is the same, but your endurance is reduced due to the temperature / cooling.
I had a similar experience. I used the GP Llama file app to compare the output of the crank meter vs. the trainer and they were within a couple watts of each other consistently. I talked to my coach about this and he said that having a higher power on outdoor rides is fairly common. He suggested possibly making a separate profile for outdoor rides so they wouldn’t skew my indoor program.
The reported power from pedal-based PM’s will depend on their crank length is set to in their app (or on the headhunt).
What crank length are you running? IIRC, most pedals assume a 172.5mm crank length by default - I could be wrong. If you’re running shorter (or longer) cranks, that could also explain some of the discrepancy.
