"The 33"-Road Bike Racing - cyclingpeaks question regarding FTP

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Lithuania
05-16-07, 07:30 AM
Does the cycling peaks software determine your FTP for you or does it just use whatever you enter for threshold under power training zones?
I am no expert but it relies on the number you input. The good thing is it will usually show you your FTP a number of ways. I have about 100 rides in CP so far. The power curve at 1 hour was right at my lab measured FTP. My heart rate chart drops off right at my threshold heart rate, and my power distribution chart drops off at my FTP.
Richard
NoRacer
05-16-07, 08:55 AM
my power distribution chart drops off at my FTP.
Richard
This is what I use--drop off of power on the 28 day distribution chart and watching for trends using the 7 day distribution chart. If a trend seems to be sticking, I'll do an adjustment, resetting the FTP number and recalculating new Coggan Training ranges.
From: http://www.cyclingpeakssoftware.com/power411/threshold.asp
A good estimate of your functional threshold power can often be obtained by simply uploading all of your training data into CyclingPeaks Software, and then examining the power frequency distribution found on your "Athlete Home Page". Because exercising above threshold power is quite strenuous and there is a limit to how long you can do so, there will often be a rather noticeable drop-off above this point in this graph. (This same approach works even better for identifying an individual's spontaneously-achieved maximal heart rate - thus reducing or even eliminating the need for formal testing!) Of course, this method works best if the time period being examined includes some high intensity training and/or racing, which serves to make the distinction between sub-threshold and supra-threshold efforts more distinct. Also, sometimes the drop-off in time spent above threshold power is more apparent when the width of each power "bin" is reduced from the default of 20 W to a smaller value, e.g., 5 or 10 W. CyclingPeaks Software has been specifically designed to allow you to customize graphs, to make such analyses possible.
Snicklefritz
05-16-07, 10:21 AM
This is what I use--drop off of power on the 28 day distribution chart and watching for trends using the 7 day distribution chart. If a trend seems to be sticking, I'll do an adjustment, resetting the FTP number and recalculating new Coggan Training ranges.
I'm curious how you transfer a specific number from the histogram to the athlete profile. If you have a range (ie bin size) of 10W say, are you taking the midpoint of the range where the dropoff occurs or the highest number?
On a related note, I was trying to do the same thing just now and apparently there was some bad power data that screws everything up. There is one specific dday where the data has a huge power spike (to 2000 W) so it makes the rest of the data really hard to see. Is there a way to "repair" that file somehow and get rid of that bad point?
Lithuania
05-16-07, 10:23 AM
I dont trust that power distribution thing at all. I already believe the threshold Im using may be a little high and the distribution method would indicate its even higher.
Anyways... all i want to know is where does cyclingpeaks derive the FTP number from when computing IF and whatnot.
NoRacer
05-16-07, 10:25 AM
Anyways... all i want to know is where does cyclingpeaks derive the FTP number from when computing IF and whatnot.
You supply the number from testing data.
The tests are as described here:
http://www.cyclingpeakssoftware.com/power411/threshold.asp
NoRacer
05-16-07, 10:32 AM
I'm curious how you transfer a specific number from the histogram to the athlete profile. If you have a range (ie bin size) of 10W say, are you taking the midpoint of the range where the dropoff occurs or the highest number?
For me 10 watts is not worth worrying about. I'm looking for trend data that indicates an increase (or decrease) in FTP. If my distributions are trending down AND I don't seem to ever hit an IF of 1.00 on hour long rides that feel like threshold rides, then I know my FTP needs to be adjusted downward. Upward adjustments would be made for the converse. I usually pick the top number of a bin. It's close enough.
Snicklefritz
05-16-07, 10:36 AM
I've just been doing tests every 4 weeks or so and then using that as a basis for entering a new FTP.
NoRacer
05-16-07, 10:39 AM
I've just been doing tests every 4 weeks or so and then using that as a basis for entering a new FTP.
That's a viable method and is more accurate then the power distribution method, if you care about that kind of accuracy.
LT Intolerant
05-16-07, 10:46 AM
I'm curious how you transfer a specific number from the histogram to the athlete profile. If you have a range (ie bin size) of 10W say, are you taking the midpoint of the range where the dropoff occurs or the highest number?
On a related note, I was trying to do the same thing just now and apparently there was some bad power data that screws everything up. There is one specific dday where the data has a huge power spike (to 2000 W) so it makes the rest of the data really hard to see. Is there a way to "repair" that file somehow and get rid of that bad point?
You can repair the data by going into the data and over-writing it by hand (see the raw data button when in the graph of a specific ride) or you can just "cut" the bad data out (much more time-friendly). I tend to cut spikes/bad data because its easy and saves time.
Hope that helps.
gene r
I just wanted to point out that when you update your FTP in the Athlete profile, make sure you add a whole new entry (FTP plus date) rather than simply changing the existing entry. That way, your profile will contain the historical data for your FTP. Obviously, the IF and TSS of your previous rides should be calculated based on your past FTP, not your current FTP.
--Steve
NoRacer
05-16-07, 05:20 PM
I just wanted to point out that when you update your FTP in the Athlete profile, make sure you add a whole new entry (FTP plus date) rather than simply changing the existing entry. That way, your profile will contain the historical data for your FTP. Obviously, the IF and TSS of your previous rides should be calculated based on your past FTP, not your current FTP.
--Steve
+1 - go to Power Training Zones; enter new FTP; select the effective date; then click the Options control and select New Zones.
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