Different FTP using Power meter vs Kinetic Trainer

Training
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I’ve been using TrainerRoad for awhile and when I’ve done my FTP tests I used my Kinetic Trainer for the power output. It gave me an FTP of 225, 247 at times. I’ve finished another 6 weeks of training and this time I used my Favero power meter pedals with power match to do a ramp test. After 6 weeks of good workouts and training my FTP is 195. Now to be fair last weekend I spent both days marching around in the hills at the Las Vegas Highland Games and probably was a little fatigued when I tested that Monday. Still I wonder if the drop is from the change in the power difference between the power meter pedals and the built in trainer power. I calibrate both the trainer and the pedals before the ramp test and before all workouts. Sometimes the trainer takes a bit more time to calibrate but it gets done. I don’t think I have lost fitness as my swimming, and running tests all show improvement but I question if there is a difference on which power meter I use. I guess I can check it later this week and do another test with the Trainer supplying the power. Any thoughts?

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Which Kinetic trainer are you using? You mention PowerMatch, so that might indicate one of their Smart Control units with the electronically controlled resistance unit?

Yes, you are essentially using two different measuring sticks, even though they both claim to be “watts”.

  • The Favero will likely be the more accurate number with respect to a “real” power value.
  • The Kinetic may well be less accurate, based on other comments I have seen.

Don’t think of it a “power loss”. It’s almost like measuring with inches and centimeters with the same number. When you mix different power measurement devices, you will very often get some separation.

If you want an idea of the difference, pair each device (trainer and power meter) with a different device (phone or head unit) and see how different they are at different power outputs.

One big thing here is to try and use the same device in all cases, for consistency. As such, using the pedals as the main power all the time makes the most sense, because they also go outside.

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