Yes, if you can’t do that workout, and since it’s not due to heat/humidity or cumulative fatigue*, then your FTP is clearly set higher than your true FTP, and is therefore set too high.
Emphasis added, because despite people claiming that “FTP is just a number around which to base workouts”, it’s really not - it is a functional expression of your muscular metabolic fitness (a.k.a., “threshold”), which is the single most important physiological determinant of your endurance performance ability. Set your FTP incorrectly, and workouts will be either too hard or too easy, and you will either struggle to complete them or you won’t progress as rapidly as you might.
(That said, no need to obsess about determining your FTP to within more than the nearest 5 W. Just avoid relying on unreliable estimates, and check your ego at the door.)
*I’m not going to say “nutrition”, because what you ate or didn’t eat in the preceding hours really has nothing to do with it, not when you blew up so early. As a general rule, folks on this forum routinely overestimate the role of acute/recent food/energy intake on performance. You can definitely screw yourself up by inducing reactive hypoglycemia or GI distress, but at best CHO ingestion has only limited benefits during workouts less than ~90 min.
@Chris1982 out of interest, (tried looking at your profile but it’s private) the progression level for the workout is high. Did you self-assign this or is this part of a plan. 10 on / 2 off threshold intervals are HARD. Very little time for recovery before you go again. You mention it was productive, but if completed, what would’ve been the progression <1 or over 1?
Rather than the FTP being too high, perhaps the workout was too much. that’s a really tough workout due to the short rests. Personally for threshold, I’d want half the interval as a rest. 10/5 not 10/2. Or no rest at all. I had a similar thing with Lamarck a few months back which is also 10/2 and I bailed in the fourth. The short rest is a killer.
For efforts up to 100% of FTP, you generally shouldn’t need any rest. If you regularly do to get through a workout, it’s a clear sign that your FTP is overestimated.
For efforts >100% of FTP, rest periods would allow you to spend more time “soaking your muscles in that metabolic milleu” (how I long thought of it). Even when I used to do 4 x 10 min at 105% (before giving up on that particular workout), I would only rest for 2.5 min between efforts (I.e., about how long it takes to restore the “energy charge” in muscle). Again, if you need more, you’re probably going too hard.
Not all muscles are equal
I think the key thing here is the level of progression for Chris1982. Or perhaps some residual fatigue from previous days, or that day. Maybe the workout was too much of a stretch for that particular system at that time.
And also, how the FTP number was calculated. AI FTP, test, self-prescribed.
A good benchmark, perhaps, would just to get on the trainer when fresh, take a decent warmup and ride threshold for 60mins and see how you get on. Or if that’s daunting, [do Gray].(Log In to TrainerRoad)
I’ve found AI FTP to inflate my number a touch, think it was 368w, which was fine for work above and below threshold but then more recently it fell a few percent due to less riding and it’s pretty much on aligned (±1%) with my real world FTP (359w)
@ all, FTP 208 → 215 was AI FTP after 3-4 solid weeks of good work.
Just wanted to say I very sincerely appreciate everyone who took time to reply and try to help. It really helps clear the weeds so I can try to find a path forward.
I was really ready to rock that day, and super stoked for the WO. These kind of “long hold” and supras are my favourite WO types. They super drain the tank, and get me super into the zone. As I said above, Fri Jun 30, when FTP was at 208, did Connell, rated it just Hard. 45 min hold @ FTP, and I absolutely loved it. So these types are supposed to be my strength, not my weakness. Just doing 10 mins @ FTP should be Moderate - Hard for me.
I’ve manually adjusted FTP back to 210 and will see how the next few Thresh & VO2 go.
It’s certainly a much trickier monkey than it originally seemed. “AI will be perfect every time” / “It’s so easy! Just set it and forget it!”
You really need to have the set FTP dialed in. Too low, Thresh will just be cruising and VO2 will be Thresh intervals, you could do them for 5 - 30 mins. Too high, and you’re not even going to finish one long interval at thresh 10 - 15 mins.
For the record, I don’t think AI FTP is bad necessarily. I’d bet, like tests, it can easily be +/- 2 - 5%. And it fluctuates more than that much day by day.
I guess the bottom line is that it’s best to have that dialed in just a touch low at first, and work your way up, than to be just a touch high, and blowing yourself up every single WO / unable to complete.
SUPER appreciate all your input!! <3