Lucy_Aspenwind]While the 20 min power x 0.95 works for some, I think it is rather lacking. I mean here you are using a generic estimate x another estimate. Example, my FTP is only 89% of my 20-min power
What is the percentage of your 20 minute power after an all out 3 minute effort, a few 1 minute efforts and some sprints. Likely the 20 minute effort that follows would be much closer than 89%.
if I used 20 min power x 0.95 as an estimate for Level 4 work, I'd blow myself to bits somewhere around the first minute or two of my 2nd set of intervals.
I agree it is unwise to use 95% of a test that only includes a 20 minute effort.
I would opt to:
a) use the cp/monod model.....just do two tests, a 3 minute & 20 minute all-out. Then plug in your results into this spreadsheet and you can predict your power at any duration:
http://velo-fit.com/articles/critical-power.pdf
Two questions on this.
One, Would you do both tests on the same day? If so how musch rest in between?
Two, The chart is designed to use at least 3 CPs. One can correct for the use of just 2. My 130 pund rider did 3 min at 254W and 20 min at 232, seperated by a 10 min rest. the Spread sheet only drops the Est 60 min to 229 Watts, that is still over 98% of the 20 min time. 95% would be 220W. This atheletes best 60 was 215W. Which was during a 1:12 TT with an NP of 217 for his best hour, at .986 IF. Hunters short test may have over estimated his FTP but less so than the Spread sheet. Hunters long test would have under estimated it at 208W.
Maybe I am doing somethng wrong with the spread sheet.
b) 60-min TT, grueling I know having done them, but there won't be any ambiguity or doubt about your true FTP. Warning: Bring the motivation and your A-game!
Once you start doing your Level 4 work it won't take long at all to figure out if your estimate is accurate or wildly optimistic. You can easily then use whatever power you do the intervals at as FTP.
Using the long test and Andys levels seems to match this athelete quite well, looking at the Watts this athelete can sustain for the different intervals. Abve L4 he is usually at the bottom of the range. But his relatively low AWC would explain this as well as the test results.
What I can bring home from this is to cut back the AWC draiing intervals a bit for this athelete, say to a 3 min and two 1 minutes before the 20 min test.
Suit the test to the rider to get the ost accurate estimate.