4X15's and FTP

specialized31 said:

I haven't tested in the last couple of months but I'm in the middle of a block of 4x15's. I'm doing these at just below max P/E with limited recovery time between each interval (7-8 minutes) and I'm getting consistent avg watts each interval +/- 3 watts and even picking up an extra 4-5 watts on the fourth effort . Would it be fair to say that the avg numbers I'm getting are close to my FTP?

I find 7-8 minutes is plenty enough recovery time to be able to tap back into anaerobic component. I'd be hesitant to use these numbers as an FTP gauge, personally.

specialized31 said:

I haven't tested in the last couple of months but I'm in the middle of a block of 4x15's. I'm doing these at just below max P/E with limited recovery time between each interval (7-8 minutes) and I'm getting consistent avg watts each interval +/- 3 watts and even picking up an extra 4-5 watts on the fourth effort . Would it be fair to say that the avg numbers I'm getting are close to my FTP?

that depends on how you define close ...

7-8min recovery from a 15-min INT is actually fairly long ... have you tried shortening them to something like 2-min? Ultimately you won't know FTP until you shorten the recoveries to zero. 😄

[quote="rmur17"] Ultimately you won't know FTP until you shorten the recoveries to zero. 😄[/QUOTE

Yeah I know I know. Can't quite muster up the motivation to crank out a 1 hour all out effort on the trainer right now. But I've picked up about 10 watts on my 4x15's the last couple of weeks so that's a good thing no matter how you measure it.

A less than fresh 20 minutes minus 5% would be closer.

specialized31 said:

I haven't tested in the last couple of months but I'm in the middle of a block of 4x15's. I'm doing these at just below max P/E with limited recovery time between each interval (7-8 minutes) and I'm getting consistent avg watts each interval +/- 3 watts and even picking up an extra 4-5 watts on the fourth effort . Would it be fair to say that the avg numbers I'm getting are close to my FTP?

In all likelihood, the average power of your 4x15s is overstating your FTP somewhat, especially since you stated that you are near your max PE and given the fairly long recovery duration. How much they overstate FTP is hard to say. You might want to try 2-3 max duration efforts at, say, 3, 5 & 15mins and use the Critical Power Model as a better first approximation of FTP.