That’s awesome. It’s another interesting data point in my 2024 goal setting. very cool.
If I put in what I’d consider to be a good racing weight the ftp is pretty much spot on. At my weight it’s off like 5%. But still pretty damn good for a number that is based on almost nothing. 
That’s fair.
The only thing I’d ask you in follow up is to look at your own power duration curve, see what your max 1-hour power had been, and then think if you could hold 88% of that for 3-hours.
Because threshold work is my weakness and I do no TT at all, but doing 88% of my one hour power for 3 hours would be hard but not terrible.
I’m sorry, but this makes no sense at all. By definition, your maximal 20 min power is something you can sustain for 20 min. Knock 5% off of that, and you will be able to go significantly longer.
IOW, the fall off in power with increasing duration isn’t nearly as steep as you imply.
That 20-30min number was just back of the napkin math and I was mostly thinking about ramp-test-derived FTP when it popped into my head.
I’m completely open to it being longer given that I pulled it out of my ass after thinking about the matter for maybe a second. This is kind of casual conversation so I wasn’t really looking to be precise.
What do you suppose the average duration that a recreational cyclist can hold their ramp-test “FTP” is? For me personally it’s usually around 20-25min. This is what I’ve seen among other people I ride with too.
And then what do you suppose the average duration that a recreational cyclist can hold their 20min derived “FTP” is? For me personally it’s around 30min. Can’t comment on others for that one though.
If you’re training regularly, and yet you can’t maintain your ‘FTP’ for at least 40 min…
…it ain’t your FTP.
The ramp test with power-only measurements is the worst way to estimate FTP. That’s the first problem. CP testing is far superior. And even then you still need to do a long test to confirm.
I’ll use me as an example. I don’t do much structured training lately and I rode for an hour at my threshold on Monday. Used CP to guide me and lactate measurements as a backup. I could do 70 minutes if I fueled and was more motivated.
Gotta find the real threshold.
Yes that’s my point.
Remember, this side conversation started with me stating that the reason why people thought that riding for 3h at 0.88 was impossible was probably because they were basing their “FTP” off ramp test or maybe 20min test results, whereas you were likely basing “FTP” off 1 hour power.
This forum would be much better with nested comments on long threads like this one 
I know. That’s why I referred to it as “FTP” 
But FTP is a thing and it’s observable. It’s the methods of estimating that are bad. Ramp test (power only or only 1 slope), 20 minute test with 5 minute blowout, two 8 minute tests, etc.
If you estimate FTP properly, normal folks like me can hold it for 60-70 minutes.
Yes, I agree with what you’ve said. I can see how you interpreted my comment the way you did though so that’s my bad for not being clear.
(Though I think sometimes TTE @ FTP can be as low as 40min or so.)
I obviously misunderstood what you were saying. In those articles, do the percentages of VO2 max they trained at equal percentage of FTP, or is it measured differently?
What would be an effective IF for shorter endurance efforts? Is it okay that they move out of Z2 and into Z3?
Well it’s not, because you don’t take your FTP to be your 20 min power, you take a percentage of it, 90-95%. Thus 0.88IF is not 88% of your 20 min power, unless you’ve misinterpreted the test result and used it directly as your FTP power. No one else has suggested that misinterpretation except yourself.
Riding at 0.86IF over 4-5 hour is a perfectly normal thing to be able to do. Unless you’ve misinterpreted what to do with your test result and thus inflated your FTP.
The average trained cyclist has an FTP of roughly 80% of VO2max. You can therefore approximate the percentage of FTP by dividing by 0.8 (or by multiplying by 1.25).
For example, if you read a classic study where participants exercised at 70-75% of VO2max for 4 h when fed carbohydrate at >100 g/h , that would have been approximately 88-94% of FTP. Similarly, Seiler’s “lower pole” around which training in his zone 1 (of 3) of roughly 60% of VO2max would be about 75% of FTP.
Less than about 70% of FTP is unlikely to induce further adaptations in someone who is already training regularly (unless perhaps carried out for many, many hours). As the intensity is progressively increased, so too is the stimulus for adaptation. There is therefore no downside to going harder (e.g., at level 3), except that it is more fatiguing. The latter is why when most people do an “endurance ride” (“LSD”, whatever) outdoors, they end up with an average power of 56-75% of FTP.* Of course, the longer the workout, the more likely it will be towards the bottom end of that range, and the shorter the workout, the more likely it will be towards the top of that range, even perhaps slightly above. For example, I did my 1 h (really 50 min once you subtract warmup and cool down) “moderate intensity filler workouts” at 83% of FTP. I never went easier than that indoors, except on the rare occasion that I felt like I needed a recovery ride, and/or I had a race in the next couple of days (then it was 50% of FTP for 1 h…never longer!).
*As discussed previously, when cycling outdoors, power tends to be highly variable, which pulls down the average. It’s really better to think in terms of IF in this context, i.e., by envisioning the effects of an isopower workout relative to FTP.
TL,DR: It’s your glycogen budget - spend it wisely.
I went back and had a look.
The longest I have held 0.88IF (by NP) for is just over 130m.
At 3 hrs, my best IF by NP was 0.84. That was in an event which lasted just over 3.5hrs. So with that in mind - as I was obviously riding in an event, rather than for a power target - I suppose 0.88 for 3 hours would have been possible.
“Fatigue” here means more than physical tiredness or wear? What about effects on hormonal system caused by high frequency going harder?
By more fatiguing I meant more difficult to recover and back it up again (and more) the next day. (Eating a diet really rich in carbohydrates obviously helps.)
Thinking about hormones is overthinking/oversimplifying it. There is FAR more to the story than that, and if anything, altered hormonal regulation (e.g., “sympathetic” overtraining) is more of a symptom than a cause.
On a more general note: true overtraining is uncommon. That’s why the numerous studies conducted a couple of decades ago that intended to induce overtraining in athletes by doubling their load for 2 wk failed to produce it. Indeed, one exercise physiologist highly active at the time suggested giving up on the paradigm, and simply study the few cases that emerged naturally.
But that is the argument against riding at that % of FTP isn’t it?
If I do an hour at 80% FTP, my subsequent hard interval day might suffer (and has in previous experience). If I knock it down to 2-3 hours at 65%, I have no issue with my hard interval days. So which is better? 2-3 hours at 65% FTP or 1 hour at 80%?
Oh yeah, 2 weeks of doubling load is just decent training camp 
I meant more 2-3 months of 4xSS + 2xZ2 per week. I bring Sweet Spot specifically as example – for me it is “happy hard”, I really like and wait for those workouts, unlike Z4+ where there might be psychological aspect in play because I slightly fear them. And yet, for whatever the reason with such regimen, I do lose motivation unlike with 2xSS/Z4/Z5 + 4xZ2 approach where I can go through whole season.
Only one way to find out: try both approaches.
Of course, that assumes you have the time (or desire) to pedal for 2-3 h on your “off” days (i.e., those not dedicated to higher intensity training or racing, or actual recovery rides).
If you don’t, your only real option* is to increase the intensity (and/the frequency of more intense workouts).
*The other options are 1) repeatedly jump from one training fad to another (e.g., polarized), in hopes of finding the “magic bullet”, or 2) accept that you’re as good as you will ever be, and enjoy your hobby as is.
And this has been the major driving factor in my training. During times where I work more and thus have less time available to train, I’ve always skewed towards harder but shorter workouts. My work has been light for now so I’ve had more time, thus I’ve been able to get in the 3 hour trainer ride.