Power in zwift vs. TR

Been zwifting to do my HVLIT and put in big hours. Started a plan this week to prep for a XCO race in 19 weeks.
After one session I noticed holding the same power target on TR vs Zwift is SIGNIFICANTLY harder. Did a 3x12@239 for my first workout and it was pretty hard. I’ve done 233 for 66 minutes on Zwift. What gives?
I’m using an elite suito smart trainer and calibrate nearly every ride.

I have all that turned off. Same resistance regardless of gradient

I’m riding right now lol
Just want to clarify this isn’t necessarily a problem. It’s just weird and I’m curious

I found holding power harder in Zwift than TrainerRoad. Both have slightly different responses. It took me a few rides to get use to both.

Same power meter / same trainer.

Note* I don’t use erg mod.

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We have seen comments over the years, that TR does a better job of handling power in general, but especially in ERG mode when compared to Z. That may be the entire difference.

For clarity, what exactly (app and such) and when exactly (before or after any warmup) are you calibrating your trainer?


Was contemplating this for some reason….

I think there are a couple things that could be at play.

  1. Too frequent and inconsistent calibration: are you always calibrating with the same method (zwift, TR, elite app)? Maybe a rogue calibration was in play when you did the 66min?

  2. Difference in ERG vs Resistance: if your cadence is erratic you could be getting “corrected” by TR and thus doing more work than if your cadence and power were more steady

  3. You aren’t as fit as you think you are? Don’t really say when the 66min effort was in relation to the workout

  4. Fueling and overall nutrition and rest: poor sleep, poor eating can lead to poor performance

  5. Watts are watts: maybe your motivation is lower for blue bars than fake scenery in which case HTFU


Lol at #5. That ain’t it.

But I think the calibration could be playing a role. Sometimes I do it right when I get on, sometimes after I’ve warmed up, sometimes not at all.

Maybe to a lesser extent relative fatigue played a roll

The 66 min effort was recent and I’ve had consistent training since then. More recently I’ve done a couple of 30ish min efforts at 240-250 watts.

I think Chad may have something with the cadence/power not being as smooth as it should making ERG mode do lots of adjustments . The last time I used TR my cadence hung out in the high nineties/low hundreds. Now, after this long Z cycle, my preferred cadence seems to drop to the mid eighties

Again, I don’t actually care as long as I’m getting in that work and prepared well for my race. Thanks for all the insight though. Y’all are smart