Intensity factor

A light bike doesn't replace good fitness.

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TheRich
Posts: 822
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

jcrr wrote:
Thu Oct 29, 2020 8:23 pm
Cycomanic wrote:
Wed Oct 28, 2020 9:25 am
jcrr wrote:
Mon Oct 26, 2020 1:09 am
Curious how others find Golden Cheetah's CP chart curves. Pretty representative of real efforts? Too high? Too low?
Like for most things the answer depends. There are a bunch of caveats, do you have enough quality data for the estimates? Ideally you'd need some efforts in the 10-30s range, some efforts around the 1-3min mark and something longer (10min+) and then you get a good estimate over the whole range. Back when I was racing the estimates I got out of GC were very good for everything below 10min or so, even if I largely only had full gas efforts of 2min and less, however things were becoming less accurate above 10-20min and it would definitely underestimate my 1h CP (or FTP), that was simply due to the nature of my racing giving me very little best efforts around 10min and above. If I did an 20min FTP test it would typically bump up my assymptote of the CP curve quite a bit.
Thanks for taking the time. I agree, the answer depends on a number of variables. N=1, I would say I have both a number of, and quality, data points across a broad range of durations, say, 30s-40min. What I find, for my data, is the model/curve is spot-on for 1min<t<15min, and way overpredicts for 15min<t<120min.
I see variation between the estimates and reality as an indicator of my weak spots.

Pretty much everything overestimates my FTP...which I interpret as a lack of endurance.

by Weenie


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jcrr
Posts: 170
Joined: Wed Nov 30, 2011 4:36 am
Location: Seattle, WA

by jcrr

TheRich wrote:
Thu Oct 29, 2020 8:33 pm
jcrr wrote:
Thu Oct 29, 2020 8:23 pm
Cycomanic wrote:
Wed Oct 28, 2020 9:25 am
jcrr wrote:
Mon Oct 26, 2020 1:09 am
Curious how others find Golden Cheetah's CP chart curves. Pretty representative of real efforts? Too high? Too low?
Like for most things the answer depends. There are a bunch of caveats, do you have enough quality data for the estimates? Ideally you'd need some efforts in the 10-30s range, some efforts around the 1-3min mark and something longer (10min+) and then you get a good estimate over the whole range. Back when I was racing the estimates I got out of GC were very good for everything below 10min or so, even if I largely only had full gas efforts of 2min and less, however things were becoming less accurate above 10-20min and it would definitely underestimate my 1h CP (or FTP), that was simply due to the nature of my racing giving me very little best efforts around 10min and above. If I did an 20min FTP test it would typically bump up my assymptote of the CP curve quite a bit.
Thanks for taking the time. I agree, the answer depends on a number of variables. N=1, I would say I have both a number of, and quality, data points across a broad range of durations, say, 30s-40min. What I find, for my data, is the model/curve is spot-on for 1min<t<15min, and way overpredicts for 15min<t<120min.
I see variation between the estimates and reality as an indicator of my weak spots.

Pretty much everything overestimates my FTP...which I interpret as a lack of endurance.
Oh, I get that what we think of 'overestimates' are really highlights of our weak spots :beerchug:

It still puzzles me that, N=1, there is a 75-80w chasm between model and my data at 30min-60min
"If it ain't broken, it could be lighter"

TobinHatesYou
Posts: 6847
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Sufferfest's developers go as far as saying it's physiologically impossible for your 5min MAP to be more than 115% of your FTP. Say you test your MAP to 400W, but your best 60min is 300W. If you are doing SST, O/U, or other aerobic workouts that scale off FTP, you should absolutely be using a value of closer to 400W/1.15 than 300W. Since both are overwhelmingly aerobic efforts, your drop off over time should be very predictable. Weakness in one aerobic effort compared to another will come down to mentality and minor muscular/neuro adaptation.

TheRich
Posts: 822
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

TobinHatesYou wrote:
Thu Oct 29, 2020 10:52 pm
Sufferfest's developers go as far as saying it's physiologically impossible for your 5min MAP to be more than 115% of your FTP. Say you test your MAP to 400W, but your best 60min is 300W. If you are doing SST, O/U, or other aerobic workouts that scale off FTP, you should absolutely be using a value of closer to 400W/1.15 than 300W. Since both are overwhelmingly aerobic efforts, your drop off over time should be very predictable. Weakness in one aerobic effort compared to another will come down to mentality and minor muscular/neuro adaptation.
How does that work out for you?


I have no doubt that there's a big mental component, both in mindset and familiarity, to extended hard efforts, and that's probably where most of our problems lie.

TobinHatesYou
Posts: 6847
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

TheRich wrote:
Thu Oct 29, 2020 11:58 pm

How does that work out for you?

It's slightly optimistic. Currently my MAP is about 118% of what I've set my FTP to for training purposes.

eins4eins
Posts: 205
Joined: Wed Sep 28, 2016 11:49 am

by eins4eins

Is there any background to these kind of statements? I think Hunter Allen also stated something like this long ago.
My CP5 is more than 120% of my 60min power. And that 60min test i did was fulgas for sure. No way i can put out that much more power to level it with the CP5

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jcrr
Posts: 170
Joined: Wed Nov 30, 2011 4:36 am
Location: Seattle, WA

by jcrr

eins4eins wrote:
Fri Oct 30, 2020 9:38 am
Is there any background to these kind of statements? I think Hunter Allen also stated something like this long ago.
My CP5 is more than 120% of my 60min power. And that 60min test i did was fulgas for sure. No way i can put out that much more power to level it with the CP5
+1.

My CP5 is close to 140% of CP60. The model estimates I should be able to come up with an additional ~1.4w/kg at CP60. I'm not sure where I would find that...
"If it ain't broken, it could be lighter"

TheRich
Posts: 822
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

eins4eins wrote:
Fri Oct 30, 2020 9:38 am
Is there any background to these kind of statements? I think Hunter Allen also stated something like this long ago.
My CP5 is more than 120% of my 60min power. And that 60min test i did was fulgas for sure. No way i can put out that much more power to level it with the CP5
I bet "you" could do it if you just/only trained for the 20 minute test...which I think some programs do for marketing purposes.

I'm at 128% of FTP...but I race enduro and endurance MTB so a 20-60 minute effort is in my dead zone. IIRC Tobin races crits, if so, that's his wheelhouse.

reedplayer
Posts: 665
Joined: Sat Nov 14, 2015 10:10 am

by reedplayer

del.

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