Hi
I had a breakthrough today after successfully completing the prescribed workout (Hardness Test Level 12) from my moderate-1 continuous plan. My HIE went up by 0.1, but my PP went down 1W, my TP down 2W and my LTP down 4W. Given this was a prescribed workout which was completed as required, why do I get the drop in TP and LTP. Is it possible for someone to explain why that would be?
Cheers
Matt
Hardness tests arenât designed to lead to breakthroughs, so unless you went all out and exceeded power targets (or you have some power meter / trainer issues) 1) you shouldnât have had a breakthrough from that workout and 2) I would flag the activity so the BT is âignoredâ.
As to why some parameters go up and some go down when you have a BT, thatâs part of the optimization. A BT does mean in aggregate your power profile improved (or you did more than Xert thought you could do) and the updated parameters reflect that
Thanks for that. i was in erg mode, so I did exactly as the session prescribed. I wasnât expecting a BT, so was a bit surprised. Have flagged the workout.
I probably should have said âin generalâ they shouldnât lead to a BT - actually I recall somewhere that for some signatures a hardness test can bring you very close and I guess thatâs what happened. Some of those have âalternatesâ for that reason. For me hardness 12 is nowhere a BT for example, but for you it seems to be. Not suggesting you did anything wrong 
The fact you had a BT and it wasnât actually a max effort for you means itâs probably worth going âall outâ at some point soon, to update your signature
If you had more in the tank when the BT occurred itâs likely you could have generated a more substantial BT had you been riding in Slope mode and extended the interval duration and/or surpassed the target watts.
You may have a latent BT ready to be expressed. On your next hard HIT workout consider switching to Slope mode when that moment arrives and go all out to a failure point. Or substitute a âfitness testâ workout on your HIT day. Or move up the Hardness Test ladder and select Level 13. In either case ride the entire workout or the hard portions in Slope mode.
You previously mentioned Slope mode on your trainer wasnât working as expected. Was that issue resolved? If not, what model trainer?
Your signature is never static in Xert and is recalculated every time you visit XO or refresh the browser page.
Values willl rise and fall incrementally on a daily basis due to TL alone independent of any BTs.
To see this in action view your Activities Table.
I have tried riding in slope mode and it does work. The issue last time was I was using auto mode, maybe there was an issue. Will further test next ride.
Just fyi, my trainer is a kickr core, never had any issues with it, before or since the odd behaviour.
Thanks for the clarification around signature. My confusion was why it impacted all 3 power metrics in that way, and tbh Iâm still not sure why that would. Happy to have someone show me the maths behind it.
To get a feel for how signature parameters interact you can manually play around with them in that activity eg increase TP a bit and drop HIE but still ensure that MPA just touches your power at the point of BT⌠youâll see that there are a large number of combinations which âworkâ⌠how Xert lands on one combination is proprietary though⌠partly I guess they check that the signature also works for other recent rides (so doesnât lead to power above MPA in the last X rides for example) and there is apparently something about the pattern of failure (which is why they say itâs important not to just stop, but to hang on and have ânaturalâ failure pattern) and I guess (but donât know) itâs about getting close to the right shape of that failure with the signature
