Trainer power higher than outdoors

Not sure if a similar topic has been posted but found nothing specific to my question in the search…

My FTP is (est) at about 290w currently and have started ramping up longer outdoor group rides and solo interval rides. What i am quickly finding is it is a LOT holding power i would hold on the Wahoo outdoors, using HR as a proxy of perceived effort. For example:

Holding an hour at 230w INDOOR would be a decent effort, but not impossible to achieve, whereas the same outdoors would feel extremely hard (i have a pretty flat loop that is uninterrupted for about an hour).

My trainer rides ignore the wahoo PM and use my Assoma bePro pedals, so there would be no difference in measurement.

Ive always heard its EASIER to put power out on the road, but i am finding it to be the opposite. Anyone experience similar issues? Could it be a PM / calibration issue? I’ve had a pro bike fit in the past 2 years, so wouldn’t think that to be an issue.

Another example is I did a 2 hour group ride at 23mph this week. Made the break and settled into a 4 man pace line with hard pulls to the end. Avg power on the entire 3 hour ride was 189w. I get drafting would lower the total output but i was toast by the time i got home, and a mixed effort ride ending in 189w avg indoors wouldn’t put me into a coma afterward.

any suggestions/ input appreciated

Have you looked at normalised as well as average power? If you haven’t come across this, here’s an explanation:

A paceline with hard pulls and surges is very different to a constant effort, and you will find that the normalised power for the ride is probably a lot higher than average power.

Yes, this is something I have experienced and haven’t seen anyone else discuss before. I am literally clueless as to why. I am thinking maybe it is something to do with inertia of the trainer or something like that but honestly I am at a complete loss.

In fairness my differences aren’t quite as pronounced as yours, I maybe lose 2-4% outdoors but it is noticeable difference during intervals.

Its a good thought. for the group ride normalized was 225w. Not something that would kill me. I have done interval rides with a normalized in the 270’s and lower average HR.

I think Janeney might be onto something with Inertia factoring in. Leaving the group ride example out as that factors in a draft, doing an hour at an easy pace (say 220) would feel quite easy on the trainer but require significant focus outdoors. Maybe its needing to shift for elevation, balancing a bike that is no longer static, or something else. Just tossing the idea out there as i have always heard the complaint of not being able to put power out indoors.

Could you share links to the recent group ride as well as an indoor ride that you felt was easier but with higher power output?

Could you share the outdoor ride and an indoor TR workout? Might give us a few more clues.

Another thought could be cadence, I find when I do a zone 2 ride outside compared to inside my cadence drops and I have to actively bring it up. But if you do the majority of your training on the trainer at high cadences, then go outside were the cadence is naturally you might lose power.

Not sure if this applies to you, but it is something I have been working on and I think it helps.

My cadence stays pretty consistent between 83-89. Oh well…