Finally got my laptop to reply to you. That will probably make it a bit easier for everyone to read!
First of all thanks for chiming in on the discussion wescaine! I know I can sometimes get a bit annoying and lost in the details simply because I am quite a curious person!
@ridgerider2 is referring to ‘optimal decay’ causing (estimated) TP to drop, which is correct. That’s different to your actual TP which should be expressed by a breakthrough. That should generally go up with training, hence your question
So if I understand you correctly here the expectation would be, that the decay overestimated my loss in TP and because all I did in that month was a sprint BT it only bumped my PP up, not my TP. Got it!
I stand guilty of avoiding longer all out efforts and instead going for shorter sprints or one minute efforts. I just find long efforts above threshold to be super uncomfortable and they always leave me rather dizzy. Not really something I like doing on a regular basis 
From your comments (soreness, low motivation), and progression chart (strong and near continuous increase in TL, with loads of breakthroughs which are by definition ‘all out’ and stressful), I suspect you are getting close to over-reaching hence seeing some decline in performance. I’d try a recovery week eg ride even easier eg 50 to 60% TP for half your usual hours for a week, then try a breakthrough again and see what comes out… you could also try a week completely off the bike… don’t get too obsessed by your TL number - it’s normal for it go down when resting, in the off season etc…
Interesting assessment! I was always wondering if I was doing too much while I was feeling super sore. But because Xert recommended high intensity workouts I was of the opinion that it would be okay. I thought soreness in the legs would be quite normal when first starting out. Maybe I did actually overdo it!
But oh well, that is why I ended up switching to a mainly low intensity zone 2 type training regime starting in December. I thought this alone would be enough to recover. Especially because I am now only following the medium 1 improvement rate, which is supposed to be doable without breaks.
But getting to your next point, which I think, is actually quite interesting:
More broadly, are you following Xert by adding intensity when blue, and riding easy endurance when yellow? It could be that two intensity sessions a week is just too much for you at the moment, as it’s probably 2 sessions out of 5 a week? Or 2 hours of sessions out of 8 hours? And there are degrees of intensity e.g. 2 weekly threshold workouts would be considered intense but easier to recover from than 2 VO2 (Rouleur) workouts
According to Xert, I should be doing a high intensitiy workout every day of the week pretty much. Even after my near BT on Monday it still had me showing as fresh. And sure enough, I COULD have gone for another high intensity workout the day after, but the literature seems to suggest that you should only do one or two high intensity workouts per week. Back when I was really hitting it hard I was often getting a yellow star and kept it yellow for a while (but only doing high intensity stuff when fresh) but now I never really seem to be able to get it to yellow. The only way for me to change my freshness is by getting it to a red star. Which I usually manage to do, if I simply ride long enough.
So I can see two options here:
- I am a soft little rider who isn’t psychologically able to go to his HIE limits
- Xert overestimates what I am able to do in the HIE area.
When I got my near BT on Monday I went for one longer-ish pretty much max effort where I only really had a couple more seconds in me. Had I known that I was actually that close to a BT I probably would have been able to push on that last little bit to get it, but it really was quite close.
After the effort I was feeling sick to the stomach and just overall not very good. So I rode on with a low intensity for a while and decided I was going to finish the workout off with some more 1 minute high intensity intervals. I was still fresh after the workout.
As you can see my HR went up all the way so those efforts were definitely max efforts. Could I have done one more effort in that time frame? Probably, yes. But the prospect of literally having to destroy myself all the way and not being able to function anymore afterwards for it to count as a high intensity workout sounds quite daunting to me…
On to your last point:
You can use the freshness slider to reflect your fatigue, and bias to getting more endurance recommendations - more base endurance training is often a good idea (which it sounds like you started with the z2 focus, but perhaps are still overdoing the intensity)
I haven’t used the freshness slider at all yet, which probably is a major oversight. I always thought that because I was technically able to follow Xert’s recommendation of going for high intensity, the freshness feedback was correct. I just wasn’t willing to do it basically. But then again, aren’t you always technically able to do a high intensity workout, so long as you are not injured?
For reference I will post a typical endurance ride here. Note that most of my endurance rides tend to have some amount of intensity in them, simply because I only do free rides in Zwift and I wouldn’t get up the mountains otherwise.
Of course I know that I could technically reduce the trainer intensity of Zwift below 100%, but I really draw a lot of motivation from the fact that the things I do have at least some sort of connection to reality. If all I did was doing some mindless simulation of something where the numbers didn’t at least try to depict reality, I’d probably just not do it…That’s why I love Xert so much. It lets you just ride without having to follow workouts precisely.
Again thanks for looking at all of this and giving me feedback! This is very much appreciated!
Same goes for week-to-week training. Rest days are mandatory if your body is not recovering.