Hey everyone,
I’m new to Xert (1 week or so) and so far, I’ve liked it a lot.
I just did Stage 1 of Zwift Unlocked, which was a punchy 16m30s race (so very short) with some kickers. I got some all-time Power PBs ranging from 4m to 15m that I cannot fully believe myself as they are a significant improvement over my previous ones. More on that later.
I got a gold breakthrough with the following increases:
The PP is in the right ballpark I think, nothing to worry about here.
I don’t know whether the HIE level/increase makes sense.
What certainly does not make any sense is the increase in TP from 323 to 363 (!!!), which is absurd. Yesterday, I did the hardness test lvl 10 - alternate with a FTP setting of 323, and I gave up in the penultimate interval. I think I mostly cracked mentally; on a better day I could have probably pushed through. Still, what I’m saying is that the previous setting of 323 also felt like it’s in the right ballpark. What I do know for sure is that 363 is way too high. During the activity itself, I held 363 over 13mins - but it was an all-out effort. No way I could sustain that much longer.
On my power PBs and power meter: I am using Assioma Duo Shi pedals and calibrate them before every ride (I know I don’t have to do that). So there’s no reason to assume measurement error explains the PBs, but the increase relative to my previous PBs made me think about that:
I improved my 5min power from 384W (from May 22 – 4.5 months ago) to 411W. I haven’t done a 5min all-out test recently, so I don’t know whether it’s realistic. I would have been super happy to crack the 400W already. Probably the best result is the 7min power of 404W, which before the race would have sounded way too high for me. 15min is at 356W, but that is relatively close to a previous short Zwift TT I did in July (3 months ago). Overall, huge increases, could be measurement error, but as I calibrated the power meter before, let’s assume it isn’t. So my question is: How to address the inflated TP value in Xert?
Here’s my breakthrough report and power chart with the previous signature:
So as you can see, my power on the last Sgurr Summit South (hill-top finish race) is higher than the MPA for quite some time when using my previous signature (see screenshot above, 323 TP).
What is the best way to address the Xert overestimate of TP? I lean towards manually editing the activity fitness signature and set the TP value to something I deem reasonable. For instance, intervals.icu gives me an FTP estimate of 332W for 12min at 367W. [Note: I set the minimum duration over which to detect the eFTP in intervals.icu to 10min as I’m probably stronger anaerobically than the average athlete. Otherwise, the intervals.icu value is 342W from 7m at 404W - but this is again too much as I’m anaerobically stronger.] So I lean towards supplying 332W to Xert as the TP to use. Not sure whether I could realistically hold that for 40-60mins, but it is a lot more appropriate than 363W as suggested by Xert.
What would you recommend? How to proceed? Thanks a lot for your help! Looking forward to learning how to best tailor Xert.
Edit: Something I noticed, but probably just a coincidence? My forecasted/planned load was 3.9 and 1.3 high and peak, respectively. When using the fitness signature that Xert suggested (with the 363W TP), my workouts today more or less perfectly reach the 3.9 and 1.3. Using my modified signature (setting TP to 332W), the completed high and peak values are now 8.5 and 2.3. Xert does not adapt the TP to match the forecasted values does it? Probably just a weird coincidence in this case…
Edit2: With the modified fitness signature of 332W TP, the effort would still be a breakthrough (see below). From my understanding, this means if I repeat the same effort, the same Xert TP correction happens again. Does this mean I should also adjust HIE? If so, to what level? Are there any power tests that you would recommend?
