I am also in this camp of not being able to make these big jumps in PL 3x15 @90% is Tray Mountain -1 a 5.2 level Sweet Spot workout, I did Round Bald -1 this week (3x15 @85%). I’m also one of the folks that has essentially been doing a Masters plan since before they became a thing, generally 6-8 hours of riding each week but only 2 hard interval sessions a week, with the rest being Z2 or outdoors (mostly commuting 45 mins each way). I think the AI generally seems to keep my FTP at the bleeding edge though of my FTP so I rarely get any PL to exceed 5 before I am bumped up a few watts and huffing and puffing my way through the level 2.8 to 4 PL level workouts again.
I’m not super old (mid 30s) but am a covid baby so started riding mid summer 2020 so feel like I’m still developing a base fitness that seems to take years to grow. Its wild seeing the Junior racers go from complete noodles to hanging in there with the Cat As in ~2 years. I definitely don’t develop fitness at that rate.
Is there a good way to assess that without being hooked up to a face mask to assess real VO2Max?
Rough and ready: compare 5 minute power to FTP 
Solution is easy, stop accepting ftp increases and work on increasing sweet spot duration. You shouldn’t be huffing and puffing your way through lower level sweet spot. If you really want to know if your ftp is correct, try and do a 30+ min effort at what you think you ftp is. I feel like the TR approach of suggesting ftp increases and using low progression levels to mask overestimation is still a major flaw
I feel like they have discussed this on the podcast before a few times, their perspective is to take the FTP progress rather than delay the FTP progression to develop more within a lower FTP. I asked about this on the forum in late 2022/early 2023 when planning out this year and saw a mixed opinion on that as well (Developing PLs more within a static FTP vs taking the FTP progress and constantly reseting the the PLs) at that time it seemed the consensus (though not unanimous) was take the FTP progression.
TR now has that feature where if you fail a 2.5 PL or lower workout they will suggest a FTP drop, so that hasn’t happened but have definitely had some 2.8 to 3.5 level workouts that were very hard after FTP increase. Wheel -3 (3.5) recently killed me, stopped about 2/3 of the way through the last interval but then it still gave me the progression, it did put me in a bit of a hole for a bit in the midst of CX season, racing back to back Sat/Sun races with other workouts and commuting during the week, failed Yukon (3.3) about a week and half later but then was back on track 3 weeks later after Wheel -3 (would have likely recovered faster without the weekend races).
The big focus in 2023 for me was progressing my volume over necessarily progressing FTP or PLs, so this year the goal was to do a minimum of 6 hours of riding per week for the full year, only 4 weeks to go to accomplish that goal.
Have been in contact with someone to potentially coach me for 2024 (not going anywhere, am a time crunched Master but just want to get closer to my potential peak fitness) so will see what they think but I would like to continue to progress my weekly volumes and start adding in some resistance training without putting myself into a hole.
I think a lot of the guys I want to be competitive with actually have a lower W/Kg than me as they probably are ~23 kg heavier than me but they also have ~70W higher FTPs (looking at their FTP ramp test results), so my W/Kg advantage doesn’t always play out, especially when things get spiky, their race power files (more than one racer) show repeated 900w spikes coming out of tight corners in races where I have been dropped badly (circuit or crit races), in normal road races I can hang in the mix and can sometimes unintentionally make small separations with small climbs or while on the front (have never had the confidence to try and make a solo break or bridge into the headwind when this occurs) but will lose positions in a pack sprint at the end.
I have specifically heard them say on the podcast that there are scenarios where you don’t want to do that, and you want to drive progression levels. Accepting a higher AIFTP does not actually mean you’re more aerobically efficient or you’re driving MLSS (and your actual FTP) higher in every case.
When I look at this year for me, I just accepted my first FTP bump since May and it was under 2%, and volume has averaged > 10 hours weekly. During that time I spent a TON of time doing SST, Tempo, and Endurance. My TTE increased, heart rate at different powers decreased, endurance pace increased. I think my Tempo / SST Progression levels all maxxed out over 9. Even having just accepted an increase, Tempo is at 6.5, Sweet Spot at 8.5. I will caveat this in that I am naturally stronger / more anaerobic with a reasonably high raw FTP, and my focus is marathon length events where I need to be able to diesel along in those lower zones all day, and if I just wanted to drive my AIFTP number higher, I could be focusing on short power and seeing that number climb faster.
If you commute frequently, and are riding 8 a week, what’s the longest ride you do?
I won’t get into the ins and outs of AIFTPD and PL, but yes, TR plans focus way too much on moving “FTP” up, and not enough on extensive work. Put the focus on going LONGER, not HARDER during base. If you’re having a good day, extend the intervals or skip the rest rather than bumping up workout difficulty. If you’re getting stronger, extend the intervals at the same power.
The consensus on the TR forum was to do what TR said on a podcast. Who knew?
The TR podcast gives a lot of really bad advice these days, and is a marketing tool first and foremost. I would take any advice given based on the present-day podcast with a grain of salt. YMMV.
How long can you hold your aiFTP?
When riding at it if you ease off 5 - 10 watts do you feel that you could carry on for much (much) longer, 5 watts over do you feel you are going to have to ease right off to keep going for any significant duration?
To me it sounds like you ‘might’ have accepted FTP gains that arent ‘real’ or at least significant enough to justify low PLs over progressing the duration of intervals and TiZ
I don’t know, because my only power based rides (my new road bike for 2024 will have a PM) are on the trainer using TR, I never have assessment of maximal efforts.
This week I did Round Bald -1 which is 3x15 at 85% and Zabriskie which is 4x8 min at 98%, last week I did Spruce -2 which is 2x20min at 85% but those are workouts rather than an all out, how long can you hold it sort of thing.
In recent history 1h45 threshold or 2 hour SS workouts like Zabriskie and Kabati. Was thinking of discussing with my potential coach getting my hard interval days during the week (currently do one on Mon or Tues and the other on Sat usually) to allow for progression through low intensity Z2 rides on Sat or Sunday from 3h up to 4h (don’t really wanna exceed 4h on the trainer) which I can see helping me get up to around 9.5h a week. Biggest week for me this year was 13h31min with a 4h41m group ride on the weekend after a week of commuting and 2 ‘hard interval’ TR workouts during the week. Last winter I did trad base and tried to push Z2 intensity and was able to do stuff like Walker, Dombai, Sandy Bay and Broken Hand. Was thinking to push volume would instead focus on progressing from Karnak to Hemp or Finley.
Intervals during the week and free up time for a 3-4h Z2 ride and you’ll see the benefits, for sure.
Hit my first hiccup…
So working overnight on Friday and Saturday probably wasn’t the best for my training and is likely playing a role in having to cut it today? 
lol i’ll commiserate one of my lasko blower fans broke last week but workouts don’t wait, this was a lot less pleasant than it should have been
Oof! So sorry. I’m going to go eat 2nd lunch now to try to avoid this fate for my own intervals tonight.
In my professional coaching opinion, yes. That’ll be hundreds of dollars please. 
I’ll give you the same advice for a dollar less. 
SSSshhhhhh. QUIET YOU.
Some great rides here. Makes my ride seem easy in comparison. Nevertheless still proud of my ride today: 80 minutes @ 90%. With basically zero decoupling (0,6% over the work-interval). Although I do feel my FTP might actually be slightly higher then the 250 I have it at right now.
Tomorrow rest day, then Wednesday 2×45’ @90% and Thursday Saturday and Sunday Z2 and Friday recovery ride
A similar week next week with Monday and Wednesday 90 and 100min at sweetspot respectively and rest Z2.
After that some VO2 probably…
80 min at 90% FTP is STOUT. Strong work.
Road racing is so multi-dimensional at some point you need to assess why you’re getting dropped by people you said you are fitter than (read that earlier) and target those weaknesses. Sweetspot is not the answer, it is a small part of a big picture. Those progression and AI FTP numbers are also difficult to glean much off on 6 hours per week, would advise testing your FTP properly.
Can you increase riding volume? Is racing the priority? Can you race more?