Inconsistent interval "target value"

There is some inconsistency in the values displayed for “interval power targets”. I have noticed this for a long time and kept ignoring it because it makes no difference to training or metrics, but I now notice often enough to mention it.

For example, yesterday I did South Twin -1 (2min intervals at 120%). The target value for the interval would therefore be FTP*1.2 = 288W *1.2 = 345.6W

  • The workout displays a target of 346 W on the web and during the workout…seems plausible for a calculated target, assuming it rounds up.
  • The summary that shows up on-screen after each interval reports a target of 345 W…looks like we rounded down here?
  • The interval summary when I analyze the ride on the web says 344 W target…not sure how we got to 344 from 345.6?

Clearly this is not an urgent issue, but curious if it can be addressed at some point. It’s especially distracting during a ramp test where you try hard to stay exactly on target. Again, I know 1 watt doesn’t matter :slight_smile:

1 Like

yes, there are little annoyances like that and I pulled up your workout from “All Rides”

346 or 344? Who knows! Good times :wink:

Try riding outside, pull up web interface, turn off elevation display, and use the lap and zoom features :wink:

More fun on the web interface - pull up a ride where you worked on sprints. Use power duration to select best 15-second power, and now checkout the summary (upper left):

Since when did 796W equal 781W?

1 Like

Calling @IvyAudrain for some help with this one. Thanks!

2 Likes

Fairly certain I reported the last one three years ago.

1 Like

Yeah, I’ve seen this reported a few times before. Yes it’s minor, but I find it really annoying too.

This is from Bluebell the other day - FTP 284, target values on the PC app were reported as 341 (rounded value of 284 * 1.2). Then you go to analyse the workout and it says the target was 337. Note this more closely matches what I actually hit using ERG mode, so maybe there’s inconsistency in what ERG mode is asking for too! But 341 would be closer to the desired 120%. Sure, a few watts between friends doesn’t really matter, but at the very least it should be a consistent value wherever it’s used and displayed.

While this kind of fix probably always get deprioritised in favour of new features, I think it’s a slippery slope when you continually ignore problems reported by paying users. Zwift, Strava … I expect better from TR.

I now wonder if they have the “window” used for average shifted by 1 second or if they are including 1 sec after (or before) the effort in the calculation. Both of these would get you to 344W…doing this weighted average with the South Twin -1 example:
(345.6W* 119sec + 115.2W * 1sec) / 120sec = 343.7W

I think it is something that should be fixed, as reporting inconsistent numbers can annoy anyone who notices it.

1 Like

To make this hypothesis more convincing, I noticed it’s only the final interval of an over-under set which is affected. Selecting it, you can see the power target (green line) does include one point at the recovery power level.

Same story if you zoom in on the “under” portion - it contains 1 data point from the “over”, but the values are close enough that it does not affect the calculated target value. 36:00 to 37:00 is actually 61 data points, not 60.

So for TR engineers (@IvyAudrain) , it looks like there are 2 things to fix:

  1. In-workout interval target rounding
    1a. live interval target value rounds UP
    1b. the interval summary rounds DOWN
  2. Target power calculated on the web uses a window that includes a data-point from the following interval in the average.
1 Like

Thanks for bringing this up! We’re looking into this now with the new apps to see if the differences are there too.

For the second issue on the web, it is a known issue with the web calculations and we just haven’t prioritized addressing that yet since the differences are so small.

To speak to that prioritization process a bit, we do empathize that it’s an issue and want to bring everything into parity, but this issue, in particular, has just been reprioritized as we work on other features that we think will help athletes more. It’s definitely still something we very much want to address in the future, and worth noting that when prioritizing issues like this, It’s not that we think this isn’t something that should get fixed, it just comes down to what we think will be the best features to help cyclists get faster. We think that what we have cooking in the immediate future will help even more!

I’ll follow up about point number one once we do some digging. Cheers!

2 Likes

Thanks. I submitted a support.trainerroad.com ticket linked to this topic too.

No issue from me on the prioritization - this “issue” has no impact on making you faster

1 Like

I understand this argument, I really do. I’m as excited for new features as anyone. However, setting accurate power levels and reporting them accurately is a fundamental core feature of the product that we are paying for. It is not working correctly and leads to confusion. There has to come a point where it gets taken seriously.

I completely agree! And for that reason, it is on the road map. Again, It’s not that we think this isnt something that should get fixed, there are just features coming that will have a greater impact in helping athletes get faster that took priority. Thanks for your patience, we understand its been a wait, and apologize for the delay in addressing this!