I do work with a lot of younger athletes and racers, so that is a clear bias of mine, however SweetSpot work should be attainable up to a certain extent. 3x20min is likely too long for you or you have your FTP set too high. FTP oversimplified is your power for 35-90mins or so, or you can go with the “1 hour power” (which is slightly incorrect). If you can hold your FTP for 1 hour, then you should be able to do 1 hour at 90% too. I’m just guessing here, but it was probably closer to a threshold workout than SweetSpot. Either that or there was just too much SweetSpot in the plan in general and the fatigue got too high by the 3rd workout of the week (I’ll leave that up to you to decide 
) If you’re new to SweetSpot or your TTE at FTP isn’t very long (35-45min) and you did a 3x10min, it should be easily completed. SS shouldn’t be that hard
More like 40 to 70 minutes, I think.
It is - if you can do one hour time trial and are able to sprint to the line, your FTP is certainly more in the 70 minute range.
If you start to fade after 45- 50 minutes, your FTP is lower than your one hour power.
And I agree on that, it isn’t 
You have to take everything in context. We looked at Cyclopaat’s power distrobution and HR distrobution and he is the only person I have ever seen that rides Zone 4 power at zone 2 HR… So he is just relaxing while doing his SS workouts… The rest of us are all taking ramp tests and over estimating our FTP’s and SS is super hard… I have seen over and over more of the top guys putting FTP much closer to CP which is closer to a ramp test result and probably like a 30m best effort in most cases… I realize this is wrong by the original definition, I just think there is a decent sized audience that has gone this way so we do have to take that into account. TrainerRoad and Zwift crowd have primarily gone to the ramp test and even Nate and the TR team say SS is hard for them at least many of their SS workouts.
What does all this mean? We need to do self-coaching and find our own correct intensity levels.
I’m not relaxing, as the workouts are often hard, even for me. It’s just that apparently, I have a low HR, adapted to what I do most.
I don’t think I would ever be able to do a one hour HIIT session every day and eventually get my HR into Z3 for the intervals and Z1 for the rests…
It’s all relative - if you do as I have done for the past ~10 years, then this is what you get. It has helped me ride those trips in the Alps 
Yes, wrong by the original definition, but while many still stick to and swear by it, the original FTP test is flawed, no matter which one you do (20 or 2x20).
I agree and “my experts” also feel the 20-minute tests are too variable for most people and so hard most people will rarely do them… So it is all a mess
Might find this interesting. I’ve had some success with it, and it gives great TTE numbers to know where you should be starting out
Imho, they’re just trying to catch up with Xert, but obviously they do disguise that in the usual clever way
I agree TP is playing catch up here. European scientists started CP, GC popularized CP, TrainerRoad popularized the ramp test that also was popular in European science circles. Xert took the CP modelled but named it Threshold not to scare all the American’s and finally TP could not sit there and have the lowest FTP on the block and switch to a more science and evidenced based model… And here we are all in the middle still dealing with legacy FTP… Really CP existed before Coggan popularized FTP and he should have saved us all a lot of time and just taken CP as it was already the standard in the scientific community rather than inventing something new…
The article is just showing a different way of testing FTP for personal use that might be more accurate than 20min or Ramp tests so you don’t over or underestimate the FTP
Oh you meant auto-calc yes catch up there too
Xert doesn’t do any kind of test. It’s an adaptive model and you just feed it a couple of parameters, related to your goal(s) and how to get there (improvement rate, based on time available and your ability to tolerate a higher rate or not).
Obviously, it helps if you have at least 3 to 6 months of reliable data, to calculate where you are when you feed these parameters.
The training plan is also adaptive, which is great for guys like me, not needing to see 3 months in advance what my workout will be by then.
Other people need a full planner, but if you do and you don’t comply for some reason, XATA will adapt.
Anyway, this is outside the scope of this thread a little
Yes, I was just offering an alternative to the standard testing approaches that has worked well for me and many others in a more accurate FTP as well as a TTE that’s more realistic. Agree this is probably outside of the scope of this thread getting into FTP testing
I just moved all this to a new thread. The first one was the cross over discussion to FTP.
So for for me and I know many others the TR ramp test and Xert auto-calc are very close. For me they are usually ± 1-2w. The other interesting thing is that the second deflection point of SMO2 is also the same. WKO mFTP is close but about 5-7w under and a 20min test is way under (with only a couple verifications)…
It seems like everyone is aligning to Xert, CP, and ramp test that produce higher numbers (bigger is better right…).
WIth SMO2 a test to failure is not required. Xert requires failures but workout failures. I personally enjoy a ramp test and just treat it like a workout but don’t obsess about the deepest level of failure.
In talking with Roger from Moxy, it sounds like SMO2 works well for some and not at all for others. I am one of the ones it works well for. Again this aligns with a ramp test not with a 20-minute test for me. I think accepting that none of this is perfectly accurate and not trying to fit all athletes to a standard set of workouts is the best approach since even with an accurate FTP different athletes perform differently.
So all this said I don’t see any reason to have a new “accurate” test because tests are generally considered inaccurate of actual LT or actual 60m TT. But if they are consistent within a person and you just adjust your workouts to match all is good.
Again this is an argument for the value of having a coach that is monitoring and suggesting adaptive workouts or self-coaching.
Lately with my riding, not training,… I don’t have any reason to do tests.
Not really failure - you can deplete MPA to TP without ‘failing’.
I used TTE on most every BT event and - no surprise there - most of my BT’s occurred (roughly) within a 25-40 minute window.
Occasionally, I would torture myself to let MPA drop to TP over a longer than an hour effort, to hone my TT skills
So how should a “good” FTP test be done?
I have made the 20 min test sometimes outdoor, but as many says it’s hard, and as I exercise for fitness, I’m not sure my FTP must be set “correct”.
You can use our app and do a ramp test like this, this is most popular and much easier than 20-minute test
You can also signup for intervals.icu and they will calculate it fairly accurately just from strava data.
“My experts” say that perfect accuracy is not possible and reasonable accuracy is fine (within 5% is ok). Now it may affect how easy it is to complete hard workouts so you might need to adjust your workouts to compensate for the being too hard or too easy.
Keep in mind that a few % overestimated may be the difference between being unable to recover properly (over doing it) and staying consistent. I’d much rather have a slightly lower FTP than slightly higher one. Which is why I do much longer and realistic tests typically than ramp, 8min, or 20min. Still they are not perfect. but there’s a much lower chance I’m overestimating which is important to me
My thoughts exactly - I never do short FTP tests, but I do 1 hour TT’s to the max, which gives me a fairly accurate “FTP”. In a sense, this is actually exactly what the “standard” definition of FTP is, but it is rarely ever tested that way.
Because it’s hard. So? TT’s are hard by definition 
As to perfect accuracy, as mentioned by @Alex’s experts: that’s true, as you should not treat it as an absolute number. Your state of mind and other (small) factors are constantly influencing your ability.
So, 5% is fine in general, but as @Jeremy points out, long term 5% too much is not.