FTP much higher than I thought? Help with analyzing intervals for FTP!

cshong88 said:

Entire ride (168w):
Duration: 1:47:30
Work: 1080 kJ
TSS: 153.4 (intensity factor 0.928)
Norm Power: 195
Distance: 29.822 mi
Min Max Avg
Power: 0 570 168 watts
Heart Rate: 9 254 190 bpm
Cadence: 25 138 103 rpm
Speed: 0 40.7 16.7 mph
Torque: 0 262 65 lb-in

This right here sets off flags for me. 1 hr 47 minutes at IF .93 - MAYBE if it was a 1hr 47 minute TT, you would do it at .93, but not likely for an interval session with rest periods during the session.

The normalized power for the 20 minutes is high because it's covering the periods of your all out intervals, and that will "skew" the NP upwards. Remember that normalized power is not WHAT you did, but it's HOW your legs will feel like you did. It does not necessarily translate to what you can do "steady state" for that same time period.

As nothing in this single ride falls within any of the "7 deadly sins" for determining FTP, there's just broad brush stroke information here. I would agree with you though that it's higher than the 210 you have defined right now.

cshong88 said:

Hi, I'm a long-time reader but not really a poster. But wanted to finally get some opinions on what my FTP is. I've always thought since last season that it is 220W but I haven't really tested that much recently. I did a ramped test on a Computrainer in january and got something around 220W roughly. I've also climbed Mt. Ascutney in 30:08 which according to analytic cycling.com, at my weight gives me about 240-250W average...I don't know exact numbers since I didn't have my powertap on my bike when I did it.

Anyways, can you guys analyze this power file and let me know what you think my FTP is? This is from a workout I did that is 6x30" maximal efforts followed by 2' of "recovery" at Z3. I have 210W as my FTP in CyclingPeaks so I tried to keep my "rest intervals" at 170-190W. I felt really good my entire ride today from my 30' warmup to my intervals which were all out and hurt a lot...and a good 30-40 min spin afterwards at tempo pace. This workout was done a trainer...the beginning and last parts of it are riding to and from the building where my team has its indoor training session.

I'm looking at my NP for 20 minutes and it's really high. Taking the conventional .95x20 min. test gives something like 245W FTP which is much higher than what I originally had as 210W (which I thought might be just slightly underestimating...I was ballparking 220W). Even my 30 minute NP is 243W and my 1 hr NP is 215W which wasn't even an all-out 1 hr effort since that includes a chill Z3ish warmup, 15 worth of the intervals, and then another 20-30 minutes at Z3ish pace. In fact, the riding after the intervals was very chill as well...once I recovered fully from the last one which took a couple minutes, I was spinning fine at Z2-3ish pace for the rest of my trainer session.

So, is my 220W estimate too low? Any ideas on what my FTP is?

By the way, I wasn't like super-rested or anything for this interval set. Just did it a day after an easy 2 hr Z1-3 ride and time trial practice 2 days before that. Thanks.

Looks like you had a great workout.

Why don't you do some formal testing with a 5 minute and 20 minute effort and plug it into the critical power spreadsheet?

You won't have to worry about guessing if your FTP is close, as this does a real good job of estimating your Critical Power.

www.velo-fit.com/articles/critical-power.pdf

www.velo-fit.com/articles/monod.xls

Jim

You are going to get a variety of responses since what you did isn't strictly according to the "training with power" protocol. I don't use that protocol and, at the risk of overstating my FTP 🙂 , have always used my best 20minutes multiplied by .95.

Your Peak 20 min from the power tap shows 227 AP and 262 NP.
2 Observations:

1 - 227 AP X .95 = ~215 FTP. The calculation is based on average power, not normalised power.

2 - Your 35 watt spread between NP and AP is HUGE for a 20 minute FTP test interval. It may be safe to say that if you even things out, you will be able to hold a higher average watts. I would guess NP and AP should be no more than 5-10 watts apart, if you pace well.

I give people who do the "5 minutes all out" before their 20min interval a lot of credit. I know my average watts would suffer if I cremated myself for 5 minutes before the test. Instead of that, doing 2 X 1min at 120-130% of FTP seems a better way to start, IMO.

cshong88 said:

So, is my 220W estimate too low? Any ideas on what my FTP is?

Nice ride. You're right to question your previous estimate, and should see how repeatable those numbers are through some testing.

There's very little use in trying to extrapolate from sub-maximal efforts, except for raising a possible flag, as it did for you. 🙂

The workout you did is a 'NP buster' - I wouldn't pay any specific attention to it in re: adjusting FTP.
In addition, the .95*20MP method of determining FTP (which some find problematic) typically refers to repeatable average power for intervals (eg 2x20's) not a one-time max NP for 20 minutes.

peterpen said:

The workout you did is a 'NP buster' - I wouldn't pay any specific attention to it in re: adjusting FTP.

That's correct. Search this forum as well as the wattage list (@google) for that term, and you'll see that 30s intervals are indeed the recipe to create one of these.

peterpen said:

The workout you did is a 'NP buster'

How do you know? You certainly can't say that just because somebody does 30 s intervals (and only 6 of them at that) that they automatically produce an "NP buster".

peterpen said:

In addition, the .95*20MP method of determining FTP (which some find problematic) typically refers to repeatable average power for intervals (eg 2x20's) not a one-time max NP for 20 minutes.

Actually, it *does* refer to a one-time maximal effort, but it is 1) based on average power, not normalized power, and 2) also entails doing an all-out 5 min effort prior to the 20 min TT.

acoggan said:

How do you know? You certainly can't say that just because somebody does 30 s intervals (and only 6 of them at that) that they automatically produce an "NP buster".

Actually, it *does* refer to a one-time maximal effort, but it is 1) based on average power, not normalized power, and 2) also entails doing an all-out 5 min effort prior to the 20 min TT.

In my experience, rides with 30s "all out" intervals (or courses with repeated ascents of hills between 30 and 60s) produce files with unusually inflated NPs. The OP was attempting to divine his FTP from the NP of such a file, which I think is a mistake. Do you think the ride in question is a good example of the robustness of the normalized power concept?

I stand corrected on the .95*20MP method of estimating FTP - thanks. In any case, the ride in question wasn't suitable for this method.

peterpen said:

In my experience, rides with 30s "all out" intervals (or courses with repeated ascents of hills between 30 and 60s) produce files with unusually inflated NPs.

How do you define "unusually inflated", or to put it another way, what is your limit of tolerance? (IME, the normalized power algorithm is usually good to w/in +/- ~5 at ~1 h.)

peterpen said:

The OP was attempting to divine his FTP from the NP of such a file, which I think is a mistake. Do you think the ride in question is a good example of the robustness of the normalized power concept?

Since I don't know his actual functional threshold power nor have I seen a plot of power-vs-time to appreciate what he actually did, I really have no idea. It is interesting to note, however, that despite it being (according to you, anyway) an "NP buster" his normalized power during the hour in which he maintained the highest average power was 215 W, i.e., just below his currently assumed functional threshold power of 220 W.

acoggan said:

How do you define "unusually inflated", or to put it another way, what is your limit of tolerance? (IME, the normalized power algorithm is usually good to w/in +/- ~5 at ~1 h.)

I'd say anything over 5% at 1h. I've seen 1hr NP's "off" (vs. FTP) by 6-10% on a course with a short, very steep hill. One 47m race on the same course produced a NP 19%> than FTP, but I don't think it's necessarily 'fair' to look at durations under 1 hr when examining the robustness of the NP concept (at least when comparing NP to FTP.)

acoggan said:

....It is interesting to note, however, that despite it being (according to you, anyway) an "NP buster" his normalized power during the hour in which he maintained the highest average power was 215 W, i.e., just below his currently assumed functional threshold power of 220 W.

Good point. Maybe what I'm trying to say is that NP might not be the best way to examine an effort shorter than 1h in duration and including 30s all out intervals. btw, it might be worth noting that I was not the only poster who described the ride as a NP buster. 😉

peterpen said:

I've seen 1hr NP's "off" (vs. FTP) by 6-10% on a course with a short, very steep hill.

Have you sent me that file? If not, would you?

peterpen said:

it might be worth noting that I was not the only poster who described the ride as a NP buster. 😉

No, John said that 30 s intervals provided a "recipe" for creating one - or, to put it another way: not every workout that includes intervals of a particular length automatically results in an "NP buster", just as not every "NP buster" is the result of intervals (deliberate or terrain-induced) of a certain length.

[quote="acoggan"]Have you sent me that file? If not, would you?
Dr. Coggan, I just sent you my file for the workout I did. Would you be able to look at it and give me your opinion on what I should set my FTP at? I'm about to start my season in two weeks and aside from my scheduled intervals and workouts, there isn't much time for a 1 hr test.

If anyone else would be kind enough to look at my file, please let me know and I will gladly e-mail you it. It's too bad that I can't attach it to this message. Thanks everyone.

[quote="cshong88"]

acoggan said:

Have you sent me that file? If not, would you?
Dr. Coggan, I just sent you my file for the workout I did. Would you be able to look at it and give me your opinion on what I should set my FTP at? I'm about to start my season in two weeks and aside from my scheduled intervals and workouts, there isn't much time for a 1 hr test.

If anyone else would be kind enough to look at my file, please let me know and I will gladly e-mail you it. It's too bad that I can't attach it to this message. Thanks everyone.

[quote="cshong88"]

acoggan said:

Have you sent me that file? If not, would you?
Dr. Coggan, I just sent you my file for the workout I did. Would you be able to look at it and give me your opinion on what I should set my FTP at? I'm about to start my season in two weeks and aside from my scheduled intervals and workouts, there isn't much time for a 1 hr test.

If anyone else would be kind enough to look at my file, please let me know and I will gladly e-mail you it. It's too bad that I can't attach it to this message. Thanks everyone.

Alex Simmons said:

Man, if everyone sent Andy random files to set FTP....

They already do. 😉

rmur17 said:

Have you been doing regular threshold/L4 workout (2x20's or other)? If so, what power have you been sustaining for these? I would trust that type of repeat workout data and average power much more than a single highly variable workout

The best predictor of performance is performance itself.

cshong88 said:

I've also climbed Mt. Ascutney in 30:08 which according to analytic cycling.com, at my weight gives me about 240-250W average

So I'm curious: was that recently, and/or at a time when your fitness was comparable to what it is now?

I ask because your mean maximal normalized power for 30 min during this workout (which Peter assumed was an "NP buster" simply because it included hard 30 s efforts) was - tada! - 244 W.

[quote="acoggan"]So I'm curious: was that recently, and/or at a time when your fitness was comparable to what it is now?

Actually it was back in November and it was the day after I rode 100 miles. I was definitely not fresh that morning, but I figured since we were in the area, that it would be a waste to not do Ascutney. But yes, from the official start to the finish line at the top, my computer gave me a time of 30:08. My fitness back then was pretty good, although I wouldn't say as good as now...add that to riding 100 miles the day before...

I think I'm going to bump up the FTP to 225W right now for the time being...any real objections to this? I would do some formal testing, but right now, I'm following a schedule of set intervals and with racing in two weeks, I don't really want to diverge from the plan right now.

cshong88 said:

I would do some formal testing, but right now, I'm following a schedule of set intervals and with racing in two weeks, I don't really want to diverge from the plan right now.

Shouldn't you be doing some longer threshold-level efforts then?