Iâm with @Captain_Doughnutman on this one (for a change ).
I found the answer to the question in Episode 194 about why sweet spot is so hard quite perplexing, in all honesty.
FTP is meant to be a good approximation of Maximum Lactate Steady State - which you should be able to maintain for 30 to 70 minutes depending on how well trained you are. Anything less than that and it really isnât your FTP, itâs just how long you can hold a certain power for, above MLSS.
In the example on the podcast the question was asked about not being able to complete even a single interval at Sweet Spot. The simplest answer was missing: FTP is set much too high if you canât complete a single 10 minute effort at, lets say, 90 or 95%.
Looking at the two more âtraditionalâ FTP tests, the 1 x 20 minute and the 2 x 8 minute protocols, itâs easy to see that failing a 10 minute interval shouldnât happen if FTP is set correctly.
Take the 20 minute test: The power that you have to hold for 20 minutes is FTP/0.95 or 105% FTP. If someone canât hold 90%, or even 95% of FTP for 10 minutes then there is no chance they could even come close to holding 105% for 20 minutes, especially after an all-out five minute effort.
Similarly, with the 8 minute test, you have to be able to hold FTP/0.9 or 111% of FTP for 8 minutes and then do it again after a complete rest. Again, not being able to hold 95% of FTP for 10 minutes when you should be able to do the test protocol should tell you something about where your FTP really lies.
All this talk of, âoh, my FTP is this but because sustaining power is not a strength, I couldnât possibly hold it for more than 10 minutesâ, is a load of ****. FTP is a measure of how good you are at holding power for a long time.
Donât start me on the Ramp TestâŚ
Ultimately FTP is a vanity metric which, unfortunately, is also the cornerstone of the current zone system as used by TrainerRoad. There is nothing wrong with that as such, although there are better methods out there, but given the lack to true maximal data that exists for a huge number of userâs profiles, wouldnât be that useful. The problems come when people cling onto the highest number they can even if it means they canât hold Sweet Spot power for 10 minutesâŚ
Thatâs not to say that Sweet Spot shouldnât feel challenging and that shorter intervals shouldnât be used to bridge to longer intervals as part of a progression, but if you are truly riding at Sweet Spot, there should be no problem holding much longer intervals with a degree of discomfort.
I actually think that proponents of Sweet Spot have got themselves in a bit of a tangle with this and may actually be prescribing threshold or very long supra-threshold efforts rather than Sweet Spot for some riders, because of the testing methods Everyone should listen to the Fascat coaching podcast about the origins of the training method - very long single efforts done outside at below FTP to exhaustion and beyond. Things have moved on a little but the principle is the same - ride below MLSS for a long time.
Anyway, Iâm away to take coverâŚ
Mike