Using NP IF and TSS during a 1/2 event

[bex]

I am seeking opinions on the above for my wifes next 1/2 IM distance event.
We have yet to get her FTP exactly, we have guessed it based on her percieved effort on the last few rides she has completed. We hope to send her out and complete it soon, but her training is not really allowing for it.
She is 117Lbs (soaking wet) and we have given her an FTP of 154
I have tried to paste a screen shot of her last ride (which covers most of the route for the 1/2 but without success. So I uploaded it, sorry.
Can someone explain how to do that?
for this latest ride which I will post when I figured it out, she "felt" she put in about 70/75% effort, and felt good on the run afterwards.
Her average power was 102w avg speed 17.8mph time 2hs 35 and distance of 46 miles
her NP was 118
IF -766
TSS 151 83
Can someone suggest what she needs to be at for NP IF TSS for a 3hr 56 mile please. Or does it seem the FTP is incorrect?
Any and all info and advice appreciated

Bex

[turbomentor]

Bex:

You have asked a LOT of questionns with no real easy answers so I'll try to tackle them as best as I can.

First: do not ever guestimate one's FTP especially based on RPE. The whole idea of training with power is precsion and metrics. To estimate your wife's FTP, have her ride a very hard TT effort as follows: 20' (2') 40'. Take the Normalized Power reading for this 42' segment and use that as an estimated FTP. Then base all of your training around that number (for instance, ride 2 hours at 80-85% FTP etc). Retest your wife regularly, perhaps every 4 weeks to see improvements and to fine tune the FTP number.

Average power is a suspect number. Normalized Power is a much better metric to use. If you use WKO+, also pay attention to VI.
TSS and IF are only going to be good if you have a good FTP number. This is paramount.
Remember that the formula for TSS is TSS = IF^2 x time(hrs) x 100 where IF = NP/FTP. So the longer you are on the bike course, the more you rack up TSS points. However, with smaller folks like your wife, this can be a bit misleading. Recommended bike pacing for a 70.3 race is about 80-85% FTP. So if your wife intends on a 3 hr time at 80% FTP, her TSS will be 192 (.8^2) x 3 x 100.

The ride you described will have her finishing in 3h 9min if she maintains that pace, so she is going to have to speed up to around 18.6 mph in order to come in at 3 hrs. Now depending on the terrain (flat/hilly) that will determine the NP needed to achieve that speed. For example: on a flat course, she may be able to sustain 19 mph at a cost of 125W. Thus if her AP is 125W, I would expect her NP to be around 135W which means her FTP would need to be around 169W.

If however it is a rolling course, she will need more watts to get the same average speed. How much more? Impossible to say without riding the course ahead of time. If the route you described below is the race course, then she needs to average 1-1.5 mph more on the same course to come in at 3 hourse.

So: get an accurate test of FTP then back compute the ride below to see what her actual TSS and IF/NP come out to be then go from their to work on a training program to build up her FTP. In the end, more Watts = more faster!!

[bex]

Thanks!

This will take me a while to digest, and I really appreciate the comprehensive response.

Cheers

Bex