How do you adjust FTP for Outdoor Rides/Different Power Metres?

Hey guys,

My current FTP on the trainer is reading 13% higher than my pedals. I’d like to do an outdoor workout but would need to adjust the FTP accordingly. Any idea how I can do this? My plan is to redo my ramp test using pedals next month so this is a temp fix.


Assuming it’s a smart, direct-drive trainer and your pedals are dual sided and accurate, your trainer is the problem.

You might need to do a factory spin-down.
This solved my problem with a smart trainer that was reading to high.

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Another solution is to simply use Power Match while training with TR. This way your indoor and outdoor power numbers are always directly comparable.

One sided.

Been there since that.

Neither of these are solutions To the questions I asked. I’ve posted another thread with my discrepancy issues which has over a 100 replies. It’s an ongoing matter. What I’m asking for is a way to change my outdoor intensity or FTP for one ride.

Perhaps I didn’t give enough details: you wrote very specifically that you knew the discrepancy between the two FTPs to a specific percentage point. I haven’t read the other thread, so I don’t know what other issues you are having.

So use Power Match and change your FTP in TR by 13 %. The outdoor workout will then use your correct FTP, and because you are using your power pedals also for future indoor workouts, you only need to do this once.

Wouldn’t that solve your problem?

The answer is you don’t. Either use power match or buy a dual sided upgrade kit. It’s silly to train using power sources with such a massive discrepancy.

Possible solutions to the question you’re asking:

  1. Don’t follow a scripted outdoor workout, but instead just do the intervals yourself using the lap button and mentally adjust 13% down (or work out the 13% reduction in advance and write it on your hand/stem to remind yourself). You can still match that ride to the prescribed workout and get it recognised in your PLs and do a survey
  2. Manually create your own outdoor workout that’s the TR workout reduced by 13%. Bit of a hassle if you’re doing this on a regular basis
  3. Manually adjust your FTP in TR every time you switch between indoors and outdoors. This is probably the best option in terms of getting the workout at the right intensity up on your head unit. Not sure how quickly workouts update and sync to and from head units though. I.e. you probably want to change FTP first, then bring up the workout you want to do outside and make sure it’s at the new lower intensity and then mark it as an outdoor workout to make sure it’s the reduced version that gets sent to your Garmin/Wahoo.

All of these are options for getting the work done at the right level outside. But using 2 such different power measurements is going to cause other issues with TR functionality like PLs and AI FTP, since TR doesn’t currently allow for different power sources that with significant differences. At least not in any way that’s visible to the user - I guess it’s possible that at the back end the machine learning is smart enough to notice that when you’re riding outdoors you’re using a different PM and that your power is lower for same HR and survey feedback and compensate for that in some way. But in the long run to get the most out of TR it’s definitely better to explore options for getting power measured more consistently across all rides. Probably covered in your other thread (I haven’t read it, might go have a look now!) but one-sided power measurement could well be at least part of the problem. I know personally I’ve had times when my L:R balance has been hovering around 42-44:56-58 due to various injury/imbalance issues, and a left-sided PM would have been extremely misleading compared to a 2-sided one.