Usually I would agree but when it comes down to the human body it’s not that simple. In reality it is more of range or zone if you like. The rate of lactate build up is dependent on the amount of fast twitch fibers doing the work.
There are some interesting articles written about fatigue rate in fast and slow twitch fibers and muscle typology in general that is worth reading.
Shades is a level 2 threshold workout.
Alarm bells ring for me when someone can’t manage a threshold workout level 4 and below.
For me this does indicate that you’re FTP is set too high unfortunately.
An athlete should be able to hold their FTP for at least 40 minutes - but you were only able to hold 95% of it for 24mins in total with big breaks in between.
The absolute max your FTP can be is 95% of what you currently have it set at.
They have most likely not recovered enough from previous workouts, maybe in combination with an optimistic FTP.
Of all the things I’ve become convinced about lately, it’s that if someone can’t do at least 2x20 sweet spot around 90% easily or 3x10 threshold, their ftp is likely to be some degree of overestimated. And the 2x20 thing is being conservative, I know some who say 60min tiz for sweet spot is the floor
If recovery was the issue then they should be struggling with other workouts as well. From how I read ops post they are only having issues with stuff ~FTP.
Distance athletes tend to think this way. But if you are a true sprinter it is amazing how fast the drop off is.
That said I don’t think this is the case here. The OP mentioned that they can ride at SS and Tempo fine. VO2 pace is fine. Likely they just need to train threshold. It hurts, we don’t want to, so don’t.
Yeah I have seen people with legit FTP numbers that they can barely hold for 30m when fresh. Would love to see the pdc of op as it will probably give us a lot of info.
I’ve experienced your first post a whole bunch of times. I’ve also ignored the “your ftp is too high” comments that you have here because how could that be? Ramp test can’t be wrong! AIFTP can’t be wrong! Garmin can’t be wrong! And having a higher FTP is somehow inflated to some sense of worth as a cyclist or whatever. But it’s just a number to set training zones. Unless you’re into TT, I guess.
If you are an anaerobically gifted rider, you will skew every FTP test shorter than 20 min, and probably a 20 min test too if you don’t do some 5-10 min efforts before you test. The ramp test and whatever AIFTP is using is based on you being a top of the bell curve rider from a power profile standard, and some of us have to be on both sides because that’s how bell curves work.
Also, cycling is this toxic sport where people pretend stuff is easy all the time. For me, threshold is doable, but it’s not pleasant. If I can’t do 2 x 20 at like say 97% of threshold, my FTP is too high.
Do a longer test.
Edit: and even all that said, I still struggle with threshold workouts, but love sweet spot workouts. It’s a weird mental block combined with me thinking I can will myself to a higher threshold. It’s stupid. Anyway, I get the frustration.
I think this could be where I’m at. On TR I struggle with level 2 threshold workouts but I’m thriving at level 4.5 VO2.
This is what threshold should feel like.
Ignore the “Your FTP is too high” crowd. For the purposes of training (not the hour record) your FTP as determined by AI FTP sets your training effort levels appropriate to what you can do. HOWEVER as someone who also despises threshold, and has a particularly difficult time with it, i can attest that TR’s expectations with threshold and the longer interval sweet spot workouts can be … optimistic for us.
I race XCO, and have for 15 years, so have a pretty well developed VO2 max capability. I also ride a lot of road, from the occasional race, to spirited group rides, to double centuries, and everything in between. What I don’t do is TT or any other predominantly threshold level efforts. Or, I didn’t until last year. I got it into my head that it would be “fun” to try hill climbing (I am not built for hill climbing), and so set that as my TR plan for 2024. I have never been so miserable during training as I was last year. The bulk of my workouts were SS or threshold, and I have never failed so many workouts in a season, nor dreaded them as much. I’ll take an hour block of 30/30’s or 5x5’s over 3x20 Threshold any day.
What I realized too late is that (imho) TR doesn’t put enough emphasis on increasing duration in SS before shortening rest, then moving to threshold. It’s a pretty quick progression from short-ish SS to long SS with little rest, then to mid-length (10min) threshold, if you’re not predisposed to that sort of effort.
Also ERG is hell if you’re not used to threshold efforts. The complete lack of micro-rest makes those efforts way worse. My strategy for ERG was (and is) to hang on as long as I could during the work intervals, then when I risked getting trapped in the ERG death spiral, I dropped back to resistance, and stayed there. Much better to finish the workout with wavy power than fail it completely trying to stay in ERG.
I’ve also noticed in past years, and again this year, that I respond really well to VO2 efforts, rising in ability much faster than other zones. I’ve also noticed that as my VO2 work improves, the other zones get dragged up with it. YMMV.
I suggest you work your way up to the longer threshold efforts, and pick the TR workouts that support that tactic (use alternates for scheduled days). Use sweet spot to your advantage, and build tolerance there before tackling the threshold that is too challenging. Also, unless you’re goals involve lots of threshold efforts, don’t sweat it too much. Do what’s prescribed if you can, or switch in a more achievable alternate if you’re sure you can’t. And ditch erg mode entirely for threshold or longer SS, unless you want the extra challenge for that workout. The mental benefit you’ll get from completing a workout will far outweigh any potential losses from less perfect power numbers, especially if you’re unable to complete it.
-Tim
Your ftp is probably too high too! I’m coaching an athlete who is able to do 130% ftp for 4min vo2 intervals, but they also were able to do all the sweet spot and threshold workouts I gave them. Why? Because I took the time to have them test their actual ftp via long efforts and their short term power in other testing. Meanwhile I’m doing my vo2 work in the 110-115% range because that’s how I test and also am able to do sweet spot because I know what my ftp actually is, and not relying on some algorithm that may or may not be correct
But your fast twitch fibers really don’t contribute to FTP (maybe, maybe in very highly trained endurance athletes they can convert to become slightly more type I), your fast twitch fibers contribute to your anaerobic capacity
This is another argument for TR to relabel AIFTP something else. Because if you can’t even do your FTP for 30 min then by definition it’s probably not your FTP.
Not saying that whatever that AIFTP number is isn’t a good target for TR style SS and Threshold intervals, but it’s not FTP.
I disagree with this.
If one struggles with even a single 10 minute interval, then what your ftp is wrong. It doesn’t matter if you did prep work with SS or built out your TTE at FTP. MLSS/FTP is by definition your steady state power for 30-70 minutes. If you can’t do just 10 minutes, your testing methodology for FTP is flawed. It doesn’t matter if you can smash out sprint or vo2 intervals at a high percentage.
TR had to invent Ai FTP because people don’t like to test. Long form tests changed my training life. Riding 30-40+ minutes at your sustainable but slightly tough wattage is not a horribly difficult workout. The first 20-30 minutes should be fairly easy. You’ll start to struggle at the outer edge of your TTE but you should never struggle in the first 10 minutes. Even a second 10 minute interval shouldn’t be very hard with a few minutes rest between the two intervals. If you do like 3x10min, you should only be feeling the burn at the end of the 3rd interval.
I hate to do this to you, but if they haven’t already, a dozen people are about to tell you that if you’re even remotely anaerobically inclined, TR VO2 workouts don’t really start to get sufficiently challenging until you get up towards level 7+ (especially the intermittent stuff)
Sorry.
The more I think about, the more I’m convinced his FTP is set too high. This comment should be a red flag to everybody:
“I managed to complete Shades (3x8 @ 95%) I found it very hard and had to be completely rested and fully fueled to manage it.”
He said he was completely rested and fully fueled, and it was still very hard to do 24 minutes at 95%. So less than 30 minutes, and not even at FTP. That just screams FTP too high to me.
Nah. We should be ignored. 
Indeed, Occam’s razor. Likely this thread will run and run though, as just doing a long form test and setting zones correctly is harder to deal with than holding onto an inflated number and doing the easier workouts in the challenging zones to swerve the issue
I was actually going to make that same comment but thought it might sound too harsh.