Another year of using WKO4 to crunch the numbers of cyclists power and other metrics has taught me that using short durations tests is a waste of time.
However short duration tests are fantastic for testing short-duration power, like sprint power, track tt power, or pursuit power. Why go to WKO4 to calculate "PMax/FRC" to get sprint power when you can just go do some sprints!
Why bother with anything "modeled" at all when the real thing is so easy to test for these days with power meters on just about every bike and trainer? (at least in Slowtwitch land). Coggan himself says something like "the best test is the performance itself" (or something very similar to that) about 12x per day
I can see modelled FTP being useful because doing a "pure" FTP test regularly sucks for those who don't do pure FTP-test-like races. (FTP is super easy for me to track because I do lots of pure 40K time trials). Though I'm fast enough at 40K that you might claim it overestimates my FTP because it's too short. :)
Well yes, I had a Sprint Cyclist in Rio, nice little cartwheel in the Keirin. She doesn't do any FTP testing.
WKO4 tells you not only your power at PMAX/FRC but the duration you can sustain this. So while a PMAX/FRC of 2400 watts sounds impressive the ability to hold it for only 3-4 means a rider who will start fast and die just as fast. Vanity PMAX/FRC.
As Andy mentioned we test the model to normalise the data. To know whether our good is good enough. To compare with others and to compare our progress. A rider turned down for a Development U23 team in U19 because they couldn't see any further progress in the rider or a rider in our coaching group signing for a World Tour team purely off his power test data (clearly a solid background on track and conti pro leading into that).
Andy does often remind us that "the best predictor of performance is performance itself" but then no two races are ever the same so is what you are testing actually relevant to your test. In cycling the FTP is strongly related to performance in everything from a pursuit to a long road race.
I would argue a well developed threshold with good time to exhaustion is the best way to start the specific preparation for a goal performance.
Hamish Ferguson: Cycling Coach http://www.roulston.co.nz