So I’ve been using Xert for the past month or so, in combination with Zwift. Great alternative for the winter season btw, and I’m contemplating using Xert for structured training outdoors as well.
At first I imported all my 2023/2024 rides to get a good baseline. I’ve done some structured training from other platforms (Join, Trainerroad, KNWU Fondo) before and a lot of free rides. It established MPA at 630-ish and TP at 217 (apparently peak TP was july when it was at 230). Which seemed very close to FTP (which was last measured at 220).
Last weekend it was nice weather so I decided to go for an outdoor free ride. During a ~8m segment I went pretty much all out (lets say 98%) and afterwards Xert adjusted my TP from 217 to 240. Its because I exceeded the Max available power after 8 minutes by a certain amount, I got that.
Then I wondered if the initial MPA when I’m fresh was ever correct. So yesterday I decided to do some all out sprints on Zwift. I reached around 800 watts for 1s and 750s for 5s. So another breakthrough but in a different department. And funnily enough, the Treshold Power got adjusted from 240 back to 224.
Now I’m not complaining about that, I actually think that’s much closer to what it should be. Am I right in suggesting that because MPA was never really correct (I never do sprints, no reason to as recreational cyclist), it was a bit lowballed, causing my breakthrough on the 8m effort. And today it noticed my MPA was actually much higher so it adjusted my fitness signature.
All in all, my TP and MPA now seem pretty much on point. And TP (224) is now super close to intervals eFTP (222)
You have proven that your PP was too low. You also proved that HIE or TP (or both) was too low when doing this eight minute interval, at least if you were able to fully drain MPA down to TP. I belive it takes some attempts to get the ratio between HIE and TP right, as increasing one of the will allow decreasing the other. That is also why the detection works best if you not suddenly stop (as you do in ERG mode), but really go all out until you can no longer produce power above TP.
Yeah, I think it’s pretty much spot on now. I don’t like tests, but I did think PP was too low so I needed to do that effort to get a more close to reality. I’d think SMART+Autogen workouts would’ve become pretty hard otherwise. In general I feel Xert power signature works best for me if I just trust the plan, so i’m doing that.
Based on your description, is sounds like 800 W in PP is correct. It might be a bit higher, but not by something that makes a real difference. However, 170 W difference is a lot will make an impact when calculating HIE and TP.
You can always try the Xert fitness tests to see if you get a new signature.
Here’s the four types of BTs (push, pull, multiple, near) – Breaking Through the Xert Way! – Xert
Once your signature is dialed in you can go months without a BT and Xert will accurately track changes to signature based values on TL alone.
Those who compte are more likely to accumlate BTs from hard efforts (drop group rides, ZRL, town line sprints, TTs, etc.),
As @hpbieker suggests you can periodically select a “fitness test” from the Library and ride it in Slope mode to validate your signature. Even if you don’t achieve a BT you’ll know your signature is dialed in by how close you get to acheiving one.
As far as sprinting goes I think you find a value to sprint workouts now and then to trigger further adaptations. For example, all-out efforts for 20-30 secs with 5-10 minute easy pedaling in between. Start with 2-3 during a ride then work your way up to performing 6-10 reps or whatever number you can muster before you begin to fade. I find this type of workout rejuvenating especially when I’ve reached 3-4 stars status. There are also a number of sprint workouts in the Library (filter by Road Sprinter).
