IF and FTP

DesFlurane said:

I think I know the answer to the question I'm about to ask but as a newbie to CP I need some reassurance.
Had the PT 3 weeks now with all rides going to CP, and I have set my FTP after a trainer session using the method in the book.
So far so good, but the IF which comes up seems too high for what are pretty sub maximal efforts.
IF of 1.0 is one hour at FTP, I think I shouldn't have many rides of +1.0? Is that correct? All my rides are IF 1.0 or more.
Unfortunately the Flow has gone to the menders, again, so it's difficult to test again and road testing is something I'm not comfortable with, very rolling terrain here with much traffic.
So looking at power distribution over the last 28 days the number I picked looks spot on, nice drop off and all that.
The power distribution for the last week shows a number possibly 15w higher!
So should I maybe be looking at NP as this does seem to give a more realistic figure?
Sorry this is a "What's my FTP" post but without an accurate figure the data appears skewed.
Thanks.

Just to clarify: You are looking at IF and not VI, correct?

Jim

otb4evr said:

Just to clarify: You are looking at IF and not VI, correct?

Jim

Yes IF.
The VI on all my rides are over 1.2. No trainer sessions.

DesFlurane said:

All my rides are IF 1.0 or more....

It's very unlikely all your rides will be IF 1.0 or higher for hour or longer rides unless you're only doing TT work and even then you'd have to nail your best one hour efforts every time you go out.

The histogram step down approach doesn't work if you're on a steady diet of structured indoor rides unless you're intentionally pushing to your breaking point regularly. That approach assumes a certain competitively random approach to riding where you attempt to hold your best efforts and sometimes go above your best one hour pace. Hard group rides and races provide the kind of data set that works well with that approach but steady SST or L4 work will just show a big step down at the higher end of the ranges you predefined.

The 95% of your best 20 minute effort approach is just a swag. It makes a lot of assumptions about a person's AWC and CP from the Monod model. Some folks will have an FTP higher than the 95% estimate and some lower. Have you tried a 2 or 3 point Monod CP test? It's not too hard to do or to analyze the results and CP is a very good estimate of FTP expressed in W/Kg. Here's a good link to the Monod CP protocol with a handy spreadsheet: velo-fit.comcritical power.pdfOpen ↗

In the meantime, I'd just bump up your FTP estimate since it's gotta be higher or you've gotta be working awfully hard everytime you get on the bike.

-Dave

Thanks for the reply,

I do feel that I am working pretty hard but it really can't be a maximal effort each time. So I have bumped up the FTP in CP 16 points which ties in with the usual NP average for my rides.

It sounds like you tested on a trainer, but you primarily ride outdoors. Many people find they can sustain 10% higher power (or even more) outside. In your case, it could be a huge difference.

I would suggest using whichever test method you can do outdoors.

jbvcoaching said:

It sounds like you tested on a trainer, but you primarily ride outdoors. Many people find they can sustain 10% higher power (or even more) outside. In your case, it could be a huge difference.

I would suggest using whichever test method you can do outdoors.

At the moment I have no trainer, though the initial test was done on one, it's now broken.
Summer here so all of the riding is outdoors.
I think that you are correct in your supposition about indoors/outdorrs FTP .
Is there any way of changing my FTP in CP retrospectively, so I can see what would happen to my last workout file with my new FTP?

On the atheletes home page, pick the date of your work out, pick New Zones out of the Options drop down enter your FTP then calculate new zones. Be sure your work outs are closed and opened after the change to reflect the test FTP.

DesFlurane said:

At the moment I have no trainer, though the initial test was done on one, it's now broken.
Summer here so all of the riding is outdoors.
I think that you are correct in your supposition about indoors/outdorrs FTP .
Is there any way of changing my FTP in CP retrospectively, so I can see what would happen to my last workout file with my new FTP?

Thanks, got it.

Changed my last workout with a bigger FTP, 3hrs 40mins over hilly terrain and that now gives an IF of 0.94 which looks much more realistic.

.94 over 3 hrs 40 minutes is extremely high. The assumption is that your max loses 5 % for doubling. So, 95% for two hours, 90% for 4 hrs. That would be a maximal effort.

Without doing specific testing, I'd check our outside mean maximal power for maybe 5 10 and 30 minutes, and use the Monod's sheet. That will give you a closer reality to your FTP than what you have now.

Or, you could go out and do actual testing. Do a 5 minute and 10 minute all out set on one day, and the 30 minute on the next.

Or, you could take your MMP for normalized power for a 1 hr all out day, to get close. Average power may/may not be closer depending on terrain.

FTP isn't something you want to be using Kentucky windage on.

Love it, "Kentucky windage"
Had to google that one!
You are absolutely correct that I need to test properly, but to get an IF of 0.86 gives me a FTP of 245w 😎
I was working on 189w :eek: :eek: 😕

There's something really weird going on.

Using the Monod spreadsheet I get figures close to my original estimate of FTP 189. this from last 7 days MMP or even my last ride MMP.
I really do need to test but am having trouble squaring the numbers, especially the IF CP is giving me.

DesFlurane said:

There's something really weird going on.

Using the Monod spreadsheet I get figures close to my original estimate of FTP 189. this from last 7 days MMP or even my last ride MMP.
I really do need to test but am having trouble squaring the numbers, especially the IF CP is giving me.

how exactly did you test again? Using Hunter's test routine with several hard efforts including a 5MP effort, then a 20MP test and taking 95% of that as FTP? Can I ask what you did for 5MP for comparison?

You mention a Tacx flow but the readings taken were from the PT correct?

Perhaps your power due to cooling/motivation/acclimatization is considerably lower indoors than out?

DesFlurane said:

I think I know the answer to the question I'm about to ask but as a newbie to CP I need some reassurance.
Had the PT 3 weeks now with all rides going to CP, and I have set my FTP after a trainer session using the method in the book.
So far so good, but the IF which comes up seems too high for what are pretty sub maximal efforts.
IF of 1.0 is one hour at FTP, I think I shouldn't have many rides of +1.0? Is that correct? All my rides are IF 1.0 or more.
Unfortunately the Flow has gone to the menders, again, so it's difficult to test again and road testing is something I'm not comfortable with, very rolling terrain here with much traffic.
So looking at power distribution over the last 28 days the number I picked looks spot on, nice drop off and all that.
The power distribution for the last week shows a number possibly 15w higher!
So should I maybe be looking at NP as this does seem to give a more realistic figure?
Sorry this is a "What's my FTP" post but without an accurate figure the data appears skewed.
Thanks.

I know that FTP can be estimated a number of ways, but my view is that one of the best ways is to do an hour at 100%. It's not easy, but it does avoid the estimation factor that can occur with some of the other methods.

rmur17 said:

how exactly did you test again? Using Hunter's test routine with several hard efforts including a 5MP effort, then a 20MP test and taking 95% of that as FTP? Can I ask what you did for 5MP for comparison?

You mention a Tacx flow but the readings taken were from the PT correct?

Perhaps your power due to cooling/motivation/acclimatization is considerably lower indoors than out?

Yes to all questions. From all my rides 5MP is about 290w.
Also agree with last statement.
It just seems so far off what I feel my FTP to be, 189w and what it might be to bring the IF to a believeable number ie <0.9
I guess I need more test rides.

I know this isn't ideal but here is my last ride power file zeros removed
[img=http://img340.imageshack.us/img340/8981/yupvu3.th.jpg]

DesFlurane said:

....Using the Monod spreadsheet I get figures close to my original estimate of FTP 189. this from last 7 days MMP or even my last ride MMP.
...

Well did you push to near your limits for the selected durations during your last 7 days? Points picked from your MMP curve are only valid if you pushed yourself to best efforts for those intervals. Otherwise it's the same as using the step down approach on constrained data where you didn't attempt to go hard.

It can even be misleading if you attempted say a hard 20 minute effort but didn't try any hard 5 minute efforts and then plugged those two numbers in the Monod spreadsheet. Your FTP and AWC will be off based on that approach. It's not hard to try for a best 3-4 minute, 6-8 minute and 15-20 minute effort and then plug those numbers into the model. You can even do two points but then you've got to modify the spreadsheet since it assumes 3 test points. You don't have to hit a particular power or time, you can just go as hard as you feel you can for say 3 minutes and then try to stretch it beyond 3 minutes at the same power if you feel some extra juice. The spreadsheet allows both power and time to be variables which makes this method pretty easy.

Good luck,
Dave

DesFlurane said:

Yes to all questions. From all my rides 5MP is about 290w.
Also agree with last statement.
It just seems so far off what I feel my FTP to be, 189w and what it might be to bring the IF to a believeable number ie <0.9
I guess I need more test rides.

if you look at the 5MP to FTP ratio, it's about 1.52 which in my recollection is quite high. For contrast mine is about 1.15 right now. Just another tidbit that points to a higher FTP but it takes some proper testing to pin it down.

I hope to be in a position to test by Sunday.

The figures from Monod and the 'method' by Rmur both give figures I don't like, 240w or so.
A great number just not one I feel I could deliver.
Why? Frightened I guess, going full chat, leaving nothing in the tank.
Oh well, I can always call a cab from the side of the road when I blow up😉

DesFlurane said:

...The figures from Monod and the 'method' by Rmur both give figures I don't like, 240w or so....

I don't know. Based on the power distribution you posted, you spent quite a bit of time above 240W on that particular ride. You might be pleasantly surprised by formal testing but I wouldn't be surprised if your FTP was even a bit higher than 240W.