My power is almost always 1 number short of the target

Been doing TR for about 5 weeks, I calibrate before every ride. One thing I’ve noticed is that my actual power usually hovers at exactly 1 number below the target. Sometimes it’ll be on the target (it’s always on target on my Garmin Edge), but when each interval finishes, my overall power reading is again always 1 number short of the target.

I’m guessing this doesn’t really matter, but still kind of annoying to see. Is this just some glitch or does this actually mean something? This happens at every power level so it’s not just targets that are difficult to hit. I online chatted with a TR rep about it but it didn’t seem to be a problem anyone’s ever brought up much and they didn’t think it was much of an issue.

Is this with ERG mode? I notice something similar on Zwift. If my target wattage is 230, it will typically settle out to 229. Sometimes hitting the “true” number, sometimes a little over, but almost always 1 watt below. I always assumed it’s something to do with the way the trainer works.

I have a Kickr, if that matters any.

Probably the ramp up/down as part of the interval and that’s causing the issue


It is with ERG mode, I have a Kickr as well. It happens no matter what (ramp or no ramp) except those short intervals where I’m ramping down, because the wattage starts out higher than the target and remains that way as it ramps down.

You need to quit slacking and push the extra watt if you want to see the numbers match. Either that or swallow your ego and lower the target so that it’s achievable.

I kid! I kid! :joy: It doesn’t really matter. Ignore it and continue crushing your workouts!


I have a wahoo Kickr bike. I just looked at a workout from last week it looks like I had the same thing. It’s definitely not something that I’ve paid much attention to. I’m sure I’ve noticed occasionally during a workout. But never gave it much thought

There’s always a ramp, you don’t go from say a rest interval to a VO2 max interval wattage instantly even if the target changes instantly.

Beyond that I also do find that my steady state power is often a watt lower than the target in Erg. The power you see in Erg is still pretty heavily smoothed and your real power is more variable than you’re seeing. I don’t know if it’s something KICKR specific but I think it errs ever so slightly on the side or caution as it tries hold the erg target in the face of human variability.

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At the end of the day it’s really nothing to worry about, but I sometimes wonder if maybe it’s a display or rounding issue within the app during the session.

I’ve seen that in the past as well (target to actual off slightly), but when I go into the web app after the session to analyze the ride, the target to actual numbers are slightly different and in many cases MATCH!

How do you plan to get faster if you can’t hit your power target?
Probably just a rounding problem

You PLAN to try HARDER next time, of course!!

In the end, even if the number on the screen isn’t changing, you are not doing perfect power. You’ve most likely got a power smoothing setting on that’s showing you a fake number.

Neither your trainer, power meter, or legs can be that precise. Turn off the fake numbers.
All About ERG Mode Power Smoothing On Wahoo KICKR Trainers | Zwift Insider

An interesting article and a feature worth knowing about, but if you read it the power smoothing has no impact on the training itself. So “fake numbers” or not, there’s nothing wrong with it.

It leads to this misconception.

I see the same thing with my Tacx trainer in ERG mode, and I’m sure it’s due to the few seconds lag while the trainer ramps up to target. It lags a bit on the way down as well, so the recovery intervals usually end up a little bit high. In other words, it’s mostly just shifting the interval a little bit out of the window shown on the graph. It’s more pronounced on shorter intervals than longer, and where there are big jumps up or down.

That said, I set the app at 101% for workouts with long intervals, 105% for ones with short bursts, and 102% for those in between. Even though I know full well that a few watts (or secomds) one way or the other makes absolutely zero difference whatsoever in training effectiveness, I still just can’t stand seeing the “official” intervals come up even 1 or 2 watts short!

the target already is higher to compensate for lag, if you “analyze online” you can see the actual targets of the intervals are lower than what you see during the workout

I’ve had numerous times where two out of the garmin/the web/the app says I’ve hit the target but other says I’ve missed it by 1w over or under, don’t fret about 1w @brianngo its just rounding.

Remember that you are training an energy zone. Only a 1 watt difference is NOT going to effect the intended result of the workout.

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indeed in spite of the prescribed target on screen being a set number we are working in zones. that being said i find the same frustration with my Saris H3 tending low to target in erg mode so when I do use erg I use the manual offset and when it really matters I just use standard mode.

  • That not quite what they do.

TR keeps the same exact power target (not higher), but they send the instruction for the resistance change to the trainer early. See this very zoomed in view of an interval start:

  • The blue blocks are the intended power target.
  • The green line is the actual trainer resistance instruction.
  • The yellow line is the actual power data.
  1. Notice how the green line is showing “early” compared to the blue target power block. This is 1 second early and is meant to make the trainer start changing 1 second sooner than the blue block target.

    • That is TR’s attempt to overcome the lag in trainer resistance changes. You will also see that they lower the target 1 second early as well at the end of an interval.
    • They are effectively shifting the trainer instructions to 1 second early for all of the interval ups/downs.
  2. As mentioned, the height of the green line does not change, which means the actual power data target is identical to the blue target blocks.

TL:DR is that TR sends the power changes early, not higher.