Old 06-23-22, 06:12 AM
  #5  
GhostRider62
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Math sort of does not work to calculate FTP or intervals based upon short efforts due to the huge variation in W' from athlete to athlete.

107-110% of FTP is just a guesstimate.

With lots of max efforts and recent data, XERT is very good at predicting power levels along the curve up to maybe 20 minutes. The PD curve of a sprinter is different from a Rouleur or a Hill Climber. So, their interval prescriptions will be a little different even if preparing for the same type of event.

When doing an interval set like that (VO2 max), I tend to use 4-6 minutes depending on fitness and have an effort level that allows me to finish the fifth set or just fail. My 8 minute power is a little higher than yours and my 5 minute interval is around 330 watts but my percentage of type 1 fibers is relatively high and my W' is relatively low. I think the key is being just able to complete it five times with the last one being wicked hard to complete.
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