Negative Breakthrough?

I just finished a pretty hard group ride. Interestingly enough, I got a breakthrough - a negative one! We all ride and train in hopes for an increase in fitness so I was surprised to get a breakthrough at the end of the ride but when I looked closely, PP, HIE and TP were all negative!

Has anyone ever got that? What gives? When I looked at my Progression Chart, for the year (2023), I’m tracking up with a few breakthroughs that confirms proper TP or some minor bumps up in TP here and there.

Thanks for your input.

In this scenario you’ve tickled MPA drawdown enough to trigger a sig calculation. The algorithm calculates to decimal pt levels so it’s certainly possible to see negative tweaks.
Had you known a BT calc was being triggered at that moment you might have pushed a bit harder/longer and one or more values would have gotten bumped up instead.
Also, consider a power meter has +/- 1% variance or more, especially outdoors.
Your signature is essentially spot on based on that effort. :slight_smile:


If you know you had a lot more to give when you got the breakthrough you can of course manually revert the fitness signature change. Are you able to tell if you were at the front when you got it? In group rides you might not push as hard as you can as you also have to keep the pace smooth for those behind (or in front of) you.

Thanks for both reply. I don’t remember specifically where I was in the group (front, back or middle) so it’s hard to tell if that was a factor.

I was coming in to the ride with some fatigue as I rode 145km the day before (at a very easy pace) but it’s still fatigue in the legs regardless.

I was curious to see if anyone had experienced that. I think it’s a good thing, as it keeps you informed of your progress (or decline) as the season progresses.

You have experienced a near breakthrough (aka fake through)

You can search the blog or forum for more detailed answer, but in essence, if the values barley decrease, apart from the scratch in the ego, is nothing to worry about.

It just means that you were close to a maximal effort to trigger a sig update, but not above.

And to reply directly to your question, yes, I been there. NEVER STOP PEDDLING WHEN YOU HEAR THE BT CHIME!!! Give it a few more seconds :triumph:

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That’s exactly our thoughts as well! Not only can Xert identify your best performances, but also your near-best, which allows you to reflect on why you weren’t able to achieve your best. Maybe it was the fatigue in your legs from the previous day (hard to capture in training data), maybe it was your nutrition or hydration, or maybe you didn’t know you were so close to a BT and stopped short of a BT unintentionally (like cresting a large/steep hill). :slight_smile: